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Automating system administration by using RHEL system roles

Red Hat Enterprise Linux 9

Consistent and repeatable configuration of RHEL deployments across multiple hosts with Red Hat Ansible Automation Platform playbooks

Red Hat Customer Content Services

Abstract

The Red Hat Enterprise Linux (RHEL) system roles are a collection of Ansible roles, modules, and playbooks that help automate the consistent and repeatable administration of RHEL systems. With RHEL system roles, you can efficiently manage large inventories of systems by running configuration playbooks from a single system.

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Chapter 1. Introduction to RHEL system roles
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By using RHEL system roles, you can remotely manage the system configurations of multiple RHEL systems across major versions of RHEL.

The following describes important terms and concepts in an Ansible environment:

Control node

A control node is the system from which you run Ansible commands and playbooks. Your control node can be an Ansible Automation Platform, Red Hat Satellite, or a RHEL host. For more information, see Preparing a control node on RHEL 9.

Important

RHEL 9 contains ansible-core 2.14. This Ansible version supports managing RHEL 7, RHEL 8, and RHEL 9 nodes. To manage RHEL 10 nodes, you require a RHEL 10 control node.

Managed node
Managed nodes are the servers and network devices that you manage with Ansible. Managed nodes are also sometimes called hosts. Ansible does not have to be installed on managed nodes. For more information, see Preparing a managed node.
Ansible playbook
In a playbook, you define the configuration you want to achieve on your managed nodes or a set of steps for the system on the managed node to perform. Playbooks are Ansible’s configuration, deployment, and orchestration language.
Inventory
In an inventory file, you list the managed nodes and specify information such as IP address for each managed node. In the inventory, you can also organize the managed nodes by creating and nesting groups for easier scaling. An inventory file is also sometimes called a hostfile.
Available roles and modules on a Red Hat Enterprise Linux 9control node

Roles provided by the rhel-system-roles package:

  • ad_integration: Active Directory integration
  • aide: Advanced Intrusion Detection Environment
  • bootloader: GRUB boot loader management
  • certificate: Certificate issuance and renewal
  • cockpit: Web console installation and configuration
  • crypto_policies: System-wide cryptographic policies
  • fapolicy: File access policy daemon configuration
  • firewall: Firewalld management
  • ha_cluster: HA Cluster management
  • journald: Systemd journald management
  • kdump: Kernel Dumps management
  • kernel_settings: Kernel settings management
  • logging: Configuring logging
  • metrics: Performance monitoring and metrics
  • nbde_client: Network Bound Disk Encryption client
  • nbde_server: Network Bound Disk Encryption server
  • network: Networking configuration
  • podman: Podman container management
  • postfix: Postfix configuration
  • postgresql: PostgreSQL configuration
  • rhc: Subscribing RHEL and configuring Insights client
  • selinux: SELinux management
  • ssh: SSH client configuration
  • sshd: SSH server configuration
  • storage: Storage management
  • systemd: Managing systemd units
  • timesync: Time synchronization
  • tlog: Terminal session recording
  • vpn: Configuring IPsec VPNs

Roles provided by the ansible-collection-microsoft-sql package:

  • microsoft.sql.server: Microsoft SQL Server

Modules provided by the ansible-collection-redhat-rhel_mgmt package:

  • rhel_mgmt.ipmi_boot: Setting boot devices
  • rhel_mgmt.ipmi_power: Setting the system power state
  • rhel_mgmt.redfish_command: Managing out-of-band controllers (OOB)
  • rhel_mgmt.redfish_command: Querying information from OOB controllers
  • rhel_mgmt.redfish_command: Managing BIOS, UEFI, and OOB controllers

Before you can use individual RHEL system roles to manage services and settings, you must prepare the control node and managed nodes.

2.1. Preparing a control node on RHEL 9
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Before using RHEL system roles, you must configure a control node. This system then configures the managed hosts from the inventory according to the playbooks.

Prerequisites

  • The system is registered to the Customer Portal.
  • A Red Hat Enterprise Linux Server subscription is attached to the system.
  • Optional: An Ansible Automation Platform subscription is attached to the system.

Procedure

  1. Create a user named ansible to manage and run playbooks: 

    [root@control-node]# useradd ansible
    Copy to Clipboard Toggle word wrap

  2. Switch to the newly created ansible user: 

    [root@control-node]# su - ansible
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    Perform the rest of the procedure as this user.

  3. Create an SSH public and private key: 

    [ansible@control-node]$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/home/ansible/.ssh/id_rsa):
Enter passphrase (empty for no passphrase): <password>
Enter same passphrase again: <password>
...
    Copy to Clipboard Toggle word wrap

    Use the suggested default location for the key file.

  4. Optional: To prevent Ansible from prompting you for the SSH key password each time you establish a connection, configure an SSH agent.

  5. Create the ~/.ansible.cfg file with the following content: 

    [defaults]
inventory = /home/ansible/inventory
remote_user = ansible

[privilege_escalation]
become = True
become_method = sudo
become_user = root
become_ask_pass = True
    Copy to Clipboard Toggle word wrap
    Note

    Settings in the ~/.ansible.cfg file have a higher priority and override settings from the global /etc/ansible/ansible.cfg file.

    With these settings, Ansible performs the following actions:

    • Manages hosts in the specified inventory file.
    • Uses the account set in the remote_user parameter when it establishes SSH connections to managed nodes.
    • Uses the sudo utility to execute tasks on managed nodes as the root user.
    • Prompts for the root password of the remote user every time you apply a playbook. This is recommended for security reasons.

  6. Create an ~/inventory file in INI or YAML format that lists the hostnames of managed hosts. You can also define groups of hosts in the inventory file. For example, the following is an inventory file in the INI format with three hosts and one host group named US: 

    managed-node-01.example.com

[US]
managed-node-02.example.com ansible_host=192.0.2.100
managed-node-03.example.com
    Copy to Clipboard Toggle word wrap

    Note that the control node must be able to resolve the hostnames. If the DNS server cannot resolve certain hostnames, add the ansible_host parameter next to the host entry to specify its IP address.

  7. Install RHEL system roles:

    • On a RHEL host without Ansible Automation Platform, install the rhel-system-roles package: 

      [root@control-node]# dnf install rhel-system-roles
      Copy to Clipboard Toggle word wrap

      This command installs the collections in the /usr/share/ansible/collections/ansible_collections/redhat/rhel_system_roles/ directory, and the ansible-core package as a dependency.

    • On Ansible Automation Platform, perform the following steps as the ansible user:

      1. Define Red Hat automation hub as the primary source for content in the ~/.ansible.cfg file.

      2. Install the redhat.rhel_system_roles collection from Red Hat automation hub: 

        [ansible@control-node]$ ansible-galaxy collection install redhat.rhel_system_roles
        Copy to Clipboard Toggle word wrap

        This command installs the collection in the ~/.ansible/collections/ansible_collections/redhat/rhel_system_roles/ directory.

Next step

2.2. Preparing a managed node
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Managed nodes are the systems listed in the inventory and which will be configured by the control node according to the playbook. You do not have to install Ansible on managed hosts.

Prerequisites

  • You prepared the control node. For more information, see Preparing a control node on RHEL 9.

  • You have SSH access from the control node.

    Important

    Direct SSH access as the root user is a security risk. To reduce this risk, you will create a local user on this node and configure a sudo policy when preparing a managed node. Ansible on the control node can then use the local user account to log in to the managed node and run playbooks as different users, such as root.

Procedure

  1. Create a user named ansible: 

    [root@managed-node-01]# useradd ansible
    Copy to Clipboard Toggle word wrap

    The control node later uses this user to establish an SSH connection to this host.

  2. Set a password for the ansible user: 

    [root@managed-node-01]# passwd ansible
Changing password for user ansible.
New password: <password>
Retype new password: <password>
passwd: all authentication tokens updated successfully.
    Copy to Clipboard Toggle word wrap

    You must enter this password when Ansible uses sudo to perform tasks as the root user.

  3. Install the ansible user’s SSH public key on the managed node:

    1. Log in to the control node as the ansible user, and copy the SSH public key to the managed node: 

      [ansible@control-node]$ ssh-copy-id managed-node-01.example.com
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/home/ansible/.ssh/id_rsa.pub"
The authenticity of host 'managed-node-01.example.com (192.0.2.100)' can't be established.
ECDSA key fingerprint is SHA256:9bZ33GJNODK3zbNhybokN/6Mq7hu3vpBXDrCxe7NAvo.
      Copy to Clipboard Toggle word wrap

    2. When prompted, connect by entering yes: 

      Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
      Copy to Clipboard Toggle word wrap

    3. When prompted, enter the password: 

      ansible@managed-node-01.example.com's password: <password>

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'managed-node-01.example.com'"
and check to make sure that only the key(s) you wanted were added.
      Copy to Clipboard Toggle word wrap

    4. Verify the SSH connection by remotely executing a command on the control node: 

      [ansible@control-node]$ ssh managed-node-01.example.com whoami
ansible
      Copy to Clipboard Toggle word wrap

  4. Create a sudo configuration for the ansible user:

    1. Create and edit the /etc/sudoers.d/ansible file by using the visudo command: 

      [root@managed-node-01]# visudo /etc/sudoers.d/ansible
      Copy to Clipboard Toggle word wrap

      The benefit of using visudo over a normal editor is that this utility provides basic checks, such as for parse errors, before installing the file.

    2. Configure a sudoers policy in the /etc/sudoers.d/ansible file that meets your requirements, for example:

      • To grant permissions to the ansible user to run all commands as any user and group on this host after entering the ansible user’s password, use: 

        ansible   ALL=(ALL) ALL
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      • To grant permissions to the ansible user to run all commands as any user and group on this host without entering the ansible user’s password, use: 

        ansible   ALL=(ALL) NOPASSWD: ALL
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    Alternatively, configure a more fine-granular policy that matches your security requirements. For further details on sudoers policies, see the sudoers(5) manual page.

Verification

  1. Verify that you can execute commands from the control node on an all managed nodes: 

    [ansible@control-node]$ ansible all -m ping
BECOME password: <password>
managed-node-01.example.com | SUCCESS => {
        ...
    	"ping": "pong"
}
...
    Copy to Clipboard Toggle word wrap

    The hard-coded all group dynamically contains all hosts listed in the inventory file.

  2. Verify that privilege escalation works correctly by running the whoami utility on all managed nodes by using the Ansible command module: 

    [ansible@control-node]$ ansible all -m command -a whoami
BECOME password: <password>
managed-node-01.example.com | CHANGED | rc=0 >>
root
...
    Copy to Clipboard Toggle word wrap

    If the command returns root, you configured sudo on the managed nodes correctly.

Chapter 3. Ansible vault
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You can use Ansible vault to encrypt sensitive data, such as passwords and API keys, in your playbooks.

Storing sensitive data in plain text in variables or other Ansible-compatible files is a security risk because any user with access to those files can read the sensitive data.

With Ansible vault, you can encrypt, decrypt, view, and edit sensitive information. They could be included as:

  • Inserted variable files in an Ansible Playbook
  • Host and group variables
  • Variable files passed as arguments when executing the playbook
  • Variables defined in Ansible roles

You can use Ansible vault to securely manage individual variables, entire files, or even structured data like YAML files. This data can then be safely stored in a version control system or shared with team members without exposing sensitive information.

Important

Files are protected with symmetric encryption of the Advanced Encryption Standard (AES256), where a single password or passphrase is used both to encrypt and decrypt the data. Note that the way this is done has not been formally audited by a third party.

To simplify management, it makes sense to set up your Ansible project so that sensitive variables and all other variables are kept in separate files, or directories. Then you can protect the files containing sensitive variables with the ansible-vault command.

Creating an encrypted file

The following command prompts you for a new vault password. Then it opens a file for storing sensitive variables using the default editor. 

# ansible-vault create vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
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Viewing an encrypted file

The following command prompts you for your existing vault password. Then it displays the sensitive contents of an already encrypted file. 

# ansible-vault view vault.yml
Vault password: <vault_password>
my_secret: "yJJvPqhsiusmmPPZdnjndkdnYNDjdj782meUZcw"
Copy to Clipboard Toggle word wrap
Editing an encrypted file

The following command prompts you for your existing vault password. Then it opens the already encrypted file for you to update the sensitive variables using the default editor. 

# ansible-vault edit vault.yml
Vault password: <vault_password>
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Encrypting an existing file

The following command prompts you for a new vault password. Then it encrypts an existing unencrypted file. 

# ansible-vault encrypt vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
Encryption successful
Copy to Clipboard Toggle word wrap
Decrypting an existing file

The following command prompts you for your existing vault password. Then it decrypts an existing encrypted file. 

# ansible-vault decrypt vault.yml
Vault password: <vault_password>
Decryption successful
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Changing the password of an encrypted file

The following command prompts you for your original vault password, then for the new vault password. 

# ansible-vault rekey vault.yml
Vault password: <vault_password>
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
Rekey successful
Copy to Clipboard Toggle word wrap
Basic application of Ansible vault variables in a playbook
---
- name: Create user accounts for all servers
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Create user from vault.yml file
      user:
        name: "{{ username }}"
        password: "{{ pwhash }}"
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You read-in the file with variables (vault.yml) in the vars_files section of your Ansible Playbook, and you use the curly brackets the same way you would do with your ordinary variables. Then you either run the playbook with the ansible-playbook --ask-vault-pass command and you enter the password manually. Or you save the password in a separate file and you run the playbook with the ansible-playbook --vault-password-file /path/to/my/vault-password-file command.

If your organization uses Microsoft Active Directory (AD) to centrally manage users, groups, and other resources, you can join your (RHEL) host to this AD. By using the ad_integration RHEL system role, you can automate the integration of Red Hat Enterprise Linux system into an Active Directory (AD) domain.

For example, if a host is joined to AD, AD users can then log in to RHEL and you can make services on the RHEL host available for authenticated AD users.

Note

The ad_integration role is for deployments using direct AD integration without an Identity Management (IdM) environment. For IdM environments, use the ansible-freeipa roles.

You can use the ad_integration RHEL system role to automate the process of joining RHEL to an Active Directory (AD) domain.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      usr: administrator
pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Active Directory integration
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Join an Active Directory
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ad_integration
      vars:
        ad_integration_user: "{{ usr }}"
        ad_integration_password: "{{ pwd }}"
        ad_integration_realm: "ad.example.com"
        ad_integration_allow_rc4_crypto: false
        ad_integration_timesync_source: "time_server.ad.example.com"
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ad_integration_allow_rc4_crypto: <true|false>

    Configures whether the role activates the AD-SUPPORT crypto policy on the managed node. By default, RHEL does not support the weak RC4 encryption but, if Kerberos in your AD still requires RC4, you can enable this encryption type by setting ad_integration_allow_rc4_crypto: true.

    Omit this the variable or set it to false if Kerberos uses AES encryption.

    ad_integration_timesync_source: <time_server>
    Specifies the NTP server to use for time synchronization. Kerberos requires a synchronized time among AD domain controllers and domain members to prevent replay attacks. If you omit this variable, the ad_integration role does not use the timesync RHEL system role to configure time synchronization on the managed node.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ad_integration/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
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Verification

  • Check if AD users, such as administrator, are available locally on the managed node: 

    $ ansible managed-node-01.example.com -m command -a 'getent passwd administrator@ad.example.com'
administrator@ad.example.com:*:1450400500:1450400513:Administrator:/home/administrator@ad.example.com:/bin/bash
    Copy to Clipboard Toggle word wrap

By using the bootloader RHEL system role, you can automate the configuration and management tasks related to the GRUB2 boot loader.

This role currently supports configuring the GRUB2 boot loader, which runs on the following CPU architectures:

  • AMD and Intel 64-bit architectures (x86-64)
  • The 64-bit ARM architecture (ARMv8.0)
  • IBM Power Systems, Little Endian (POWER9)

You can use the bootloader RHEL system role to update the existing entries in the GRUB boot menu in an automated fashion. This way you can efficiently pass specific kernel command-line parameters that can optimize the performance or behavior of your systems.

For example, if you leverage systems, where detailed boot messages from the kernel and init system are not necessary, use bootloader to apply the quiet parameter to your existing boot loader entries on your managed nodes to achieve a cleaner, less cluttered, and more user-friendly booting experience.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • You identified the kernel that corresponds to the boot loader entry you want to update.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configuration and management of GRUB boot loader
  hosts: managed-node-01.example.com
  tasks:
    - name: Update existing boot loader entries
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.bootloader
      vars:
        bootloader_settings:
          - kernel:
              path: /boot/vmlinuz-5.14.0-362.24.1.el9_3.aarch64
            options:
              - name: quiet
                state: present
        bootloader_reboot_ok: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    kernel
    Specifies the kernel connected with the boot loader entry that you want to update.
    options
    Specifies the kernel command-line parameters to update for your chosen boot loader entry (kernel).
    bootloader_reboot_ok: true
    The role detects that a reboot is required for the changes to take effect and performs a restart of the managed node.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.bootloader/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Check that your specified boot loader entry has updated kernel command-line parameters: 

    # ansible managed-node-01.example.com -m ansible.builtin.command -a 'grubby --info=ALL'
managed-node-01.example.com | CHANGED | rc=0 >>
...
index=1
kernel="/boot/vmlinuz-5.14.0-362.24.1.el9_3.aarch64"
args="ro crashkernel=1G-4G:256M,4G-64G:320M,64G-:576M rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap $tuned_params quiet"
root="/dev/mapper/rhel-root"
initrd="/boot/initramfs-5.14.0-362.24.1.el9_3.aarch64.img $tuned_initrd"
title="Red Hat Enterprise Linux (5.14.0-362.24.1.el9_3.aarch64) 9.4 (Plow)"
id="2c9ec787230141a9b087f774955795ab-5.14.0-362.24.1.el9_3.aarch64"
...
    Copy to Clipboard Toggle word wrap

You can use the bootloader RHEL system role to set a password to the GRUB boot menu in an automated fashion. This way you can efficiently prevent unauthorized users from modifying boot parameters, and to have better control over the system boot.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configuration and management of GRUB boot loader
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Set the bootloader password
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.bootloader
      vars:
        bootloader_password: "{{ pwd }}"
        bootloader_reboot_ok: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    bootloader_password: "{{ pwd }}"
    The variable ensures protection of boot parameters with a password.
    bootloader_reboot_ok: true
    The role detects that a reboot is required for the changes to take effect and performs a restart of the managed node.
    Important

    Changing the boot loader password is not an idempotent transaction. This means that if you apply the same Ansible playbook again, the result will not be the same, and the state of the managed node will change.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.bootloader/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. On your managed node during the GRUB boot menu screen, press the e key for edit.

    GRUB2 boot loader menu
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    GRUB2 boot loader menu

  2. You are prompted for a username and a password:

    GRUB2 menu lock
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    GRUB2 menu lock
    Enter username: root
    The boot loader username is always root and you do not need to specify it in your Ansible playbook.
    Enter password: <password>
    The boot loader password corresponds to the pwd variable that you defined in the vault.yml file.

  3. You can view or edit configuration of the particular boot loader entry:

    GRUB2 boot loader entry details
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    GRUB2 boot loader entry details

You can use the bootloader RHEL system role to configure a timeout for the GRUB2 boot loader menu in an automated fashion. This way you can efficiently update a period of time during which you can intervene and select a non-default boot entry for various purposes.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configuration and management of the GRUB boot loader
  hosts: managed-node-01.example.com
  tasks:
    - name: Update the boot loader timeout
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.bootloader
      vars:
        bootloader_timeout: 10
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    bootloader_timeout: 10
    Input an integer to control for how long the GRUB boot loader menu is displayed before booting the default entry.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.bootloader/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. Remotely restart your managed node: 

    # ansible managed-node-01.example.com -m ansible.builtin.reboot
managed-node-01.example.com | CHANGED => {
    "changed": true,
    "elapsed": 21,
    "rebooted": true
}
    Copy to Clipboard Toggle word wrap

  2. On the managed node, observe the GRUB boot menu screen.

    GRUB2 boot loader menu timeout
    View larger image
    GRUB2 boot loader menu timeout
    The highlighted entry will be executed automatically in 10s

    For how long this boot menu is displayed before GRUB automatically uses the default entry.

    • Alternative: you can remotely query for the "timeout" settings in the /boot/grub2/grub.cfg file of your managed node: 

      # ansible managed-node-01.example.com -m ansible.builtin.command -a "grep 'timeout' /boot/grub2/grub.cfg"
managed-node-01.example.com | CHANGED | rc=0 >>
if [ x$feature_timeout_style = xy ] ; then
  set timeout_style=menu
  set timeout=10
# Fallback normal timeout code in case the timeout_style feature is
  set timeout=10
if [ x$feature_timeout_style = xy ] ; then
    set timeout_style=menu
    set timeout=10
    set orig_timeout_style=${timeout_style}
    set orig_timeout=${timeout}
      # timeout_style=menu + timeout=0 avoids the countdown code keypress check
      set timeout_style=menu
      set timeout=10
      set timeout_style=hidden
      set timeout=10
if [ x$feature_timeout_style = xy ]; then
  if [ "${menu_show_once_timeout}" ]; then
    set timeout_style=menu
    set timeout=10
    unset menu_show_once_timeout
    save_env menu_show_once_timeout
      Copy to Clipboard Toggle word wrap

You can use the bootloader RHEL system role to gather information about the GRUB boot loader entries in an automated fashion. You can use this information to verify the correct configuration of system boot parameters, such as kernel and initial RAM disk image paths.

As a result, you can for example:

  • Prevent boot failures.
  • Revert to a known good state when troubleshooting.
  • Be sure that security-related kernel command-line parameters are correctly configured.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configuration and management of GRUB boot loader
  hosts: managed-node-01.example.com
  tasks:
    - name: Gather information about the boot loader configuration
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.bootloader
      vars:
        bootloader_gather_facts: true

    - name: Display the collected boot loader configuration information
      debug:
        var: bootloader_facts
    Copy to Clipboard Toggle word wrap

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.bootloader/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • After you run the preceding playbook on the control node, you will see a similar command-line output as in the following example: 

    ...
    "bootloader_facts": [
        {
            "args": "ro crashkernel=1G-4G:256M,4G-64G:320M,64G-:576M rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap $tuned_params quiet",
            "default": true,
            "id": "2c9ec787230141a9b087f774955795ab-5.14.0-362.24.1.el9_3.aarch64",
            "index": "1",
            "initrd": "/boot/initramfs-5.14.0-362.24.1.el9_3.aarch64.img $tuned_initrd",
            "kernel": "/boot/vmlinuz-5.14.0-362.24.1.el9_3.aarch64",
            "root": "/dev/mapper/rhel-root",
            "title": "Red Hat Enterprise Linux (5.14.0-362.24.1.el9_3.aarch64) 9.4 (Plow)"
        }
    ]
...
    Copy to Clipboard Toggle word wrap

    The command-line output shows the following notable configuration information about the boot entry:

    args
    Command-line parameters passed to the kernel by the GRUB2 boot loader during the boot process. They configure various settings and behaviors of the kernel, initramfs, and other boot-time components.
    id
    Unique identifier assigned to each boot entry in a boot loader menu. It consists of machine ID and the kernel version.
    root
    The root filesystem for the kernel to mount and use as the primary filesystem during the boot.

Many services, such as web servers, use TLS to encrypt connections with clients. By using the certificate RHEL system role, you can automate the generation of private keys on managed nodes. Additionally, the role configures the certmonger service to request a certificate from a CA.

For testing purposes, you can use the certificate role to create self-signed certificates instead of requesting a signed certificate from a CA.

By using the certificate RHEL system role, you can automate the process of creating a private key and letting the certmonger service request a certificate from the Identity Management (IdM) certificate authority (CA). By default, certmonger will also renew the certificate before it expires.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed node is a member of an IdM domain and the domain uses the IdM-integrated CA.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create certificates
  hosts: managed-node-01.example.com
  tasks:
    - name: Create a self-signed certificate
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.certificate
      vars:
        certificate_requests:
          - name: web-server
            ca: ipa
            dns: www.example.com
            principal: HTTP/www.example.com@EXAMPLE.COM
            run_before: systemctl stop httpd.service
            run_after: systemctl start httpd.service
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    name: <path_or_file_name>

    Defines the name or path of the generated private key and certificate file:

    • If you set the variable to web-server, the role stores the private key in the /etc/pki/tls/private/web-server.key and the certificate in the /etc/pki/tls/certs/web-server.crt files.

    • If you set the variable to a path, such as /tmp/web-server, the role stores the private key in the /tmp/web-server.key and the certificate in the /tmp/web-server.crt files.

      Note that the directory you use must have the cert_t SELinux context set. You can use the selinux RHEL system role to manage SELinux contexts.

    ca: ipa
    Defines that the role requests the certificate from an IdM CA.
    dns: <hostname_or_list_of_hostnames>
    Sets the hostnames that the Subject Alternative Names (SAN) field in the issued certificate contains. You can use a wildcard (*) or specify multiple names in YAML list format.
    principal: <kerberos_principal>
    Optional: Sets the Kerberos principal that should be included in the certificate.
    run_before: <command>
    Optional: Defines a command that certmonger should execute before requesting the certificate from the CA.
    run_after: <command>
    Optional: Defines a command that certmonger should execute after it received the issued certificate from the CA.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.certificate/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • List the certificates that the certmonger service manages: 

    # ansible managed-node-01.example.com -m command -a 'getcert list'
...
Number of certificates and requests being tracked: 1.
Request ID '20240918142211':
        status: MONITORING
        stuck: no
        key pair storage: type=FILE,location='/etc/pki/tls/private/web-server.key'
        certificate: type=FILE,location='/etc/pki/tls/certs/web-server.crt'
        CA: IPA
        issuer: CN=Certificate Authority,O=EXAMPLE.COM
        subject: CN=www.example.com
        issued: 2024-09-18 16:22:11 CEST
        expires: 2025-09-18 16:22:10 CEST
        dns: www.example.com
        key usage: digitalSignature,keyEncipherment
        eku: id-kp-serverAuth,id-kp-clientAuth
        pre-save command: systemctl stop httpd.service
        post-save command: systemctl start httpd.service
        track: yes
        auto-renew: yes
    Copy to Clipboard Toggle word wrap

If you require a TLS certificate for a test environment, you can use a self-signed certificate. By using the certificate RHEL system role, you can automate the process of creating a private key and letting the certmonger service create a self-signed certificate.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create certificates
  hosts: managed-node-01.example.com
  tasks:
    - name: Create a self-signed certificate
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.certificate
      vars:
        certificate_requests:
          - name: web-server
            ca: self-sign
            dns: test.example.com
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    name: <path_or_file_name>

    Defines the name or path of the generated private key and certificate file:

    • If you set the variable to web-server, the role stores the private key in the /etc/pki/tls/private/web-server.key and the certificate in the /etc/pki/tls/certs/web-server.crt files.

    • If you set the variable to a path, such as /tmp/web-server, the role stores the private key in the /tmp/web-server.key and the certificate in the /tmp/web-server.crt files.

      Note that the directory you use must have the cert_t SELinux context set. You can use the selinux RHEL system role to manage SELinux contexts.

    ca: self-sign
    Defines that the role created a self-signed certificate.
    dns: <hostname_or_list_of_hostnames>
    Sets the hostnames that the Subject Alternative Names (SAN) field in the issued certificate contains. You can use a wildcard (*) or specify multiple names in YAML list format.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.certificate/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • List the certificates that the certmonger service manages: 

    # ansible managed-node-01.example.com -m command -a 'getcert list'
...
Number of certificates and requests being tracked: 1.
Request ID '20240918133610':
	status: MONITORING
	stuck: no
	key pair storage: type=FILE,location='/etc/pki/tls/private/web-server.key'
	certificate: type=FILE,location='/etc/pki/tls/certs/web-server.crt'
	CA: local
	issuer: CN=c32b16d7-5b1a4c5a-a953a711-c3ca58fb,CN=Local Signing Authority
	subject: CN=test.example.com
	issued: 2024-09-18 15:36:10 CEST
	expires: 2025-09-18 15:36:09 CEST
	dns: test.example.com
	key usage: digitalSignature,keyEncipherment
	eku: id-kp-serverAuth,id-kp-clientAuth
	pre-save command:
	post-save command:
	track: yes
	auto-renew: yes
    Copy to Clipboard Toggle word wrap

With the cockpit RHEL system role, you can automatically deploy and enable the web console on multiple RHEL systems.

You can use the cockpit system role to automate installing and enabling the RHEL web console on multiple systems.

You use the cockpit system role to:

  • Install the RHEL web console.
  • Allow the firewalld and selinux system roles to configure the system for opening new ports.
  • Set the web console to use a certificate from the ipa trusted certificate authority instead of using a self-signed certificate.
Note

You do not have to call the firewall or certificate system roles in the playbook to manage the firewall or create the certificate. The cockpit system role calls them automatically as needed.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage the RHEL web console
  hosts: managed-node-01.example.com
  tasks:
    - name: Install RHEL web console
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.cockpit
      vars:
        cockpit_packages: default
        cockpit_manage_selinux: true
        cockpit_manage_firewall: true
        cockpit_certificates:
          - name: /etc/cockpit/ws-certs.d/01-certificate
            dns: ['localhost', 'www.example.com']
            ca: ipa
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    cockpit_manage_selinux: true
    Allow using the selinux system role to configure SELinux for setting up the correct port permissions on the websm_port_t SELinux type.
    cockpit_manage_firewall: true
    Allow the cockpit system role to use the firewalld system role for adding ports.
    cockpit_certificates: <YAML_dictionary>

    By default, the RHEL web console uses a self-signed certificate. Alternatively, you can add the cockpit_certificates variable to the playbook and configure the role to request certificates from an IdM certificate authority (CA) or to use an existing certificate and private key that is available on the managed node.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.cockpit/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

By using the crypto_policies RHEL system role, you can quickly and consistently configure custom cryptographic policies across many operating systems in an automated fashion.

Custom cryptographic policies are a set of rules and configurations that manage the use of cryptographic algorithms and protocols. These policies help you to maintain a protected, consistent, and manageable security environment across multiple systems and applications.

You can use the crypto_policies RHEL system role to configure the FUTURE cryptographic policy on your managed nodes.

The FUTURE policy helps to achieve, for example:

  • Future-proofing against emerging threats: anticipates advancements in computational power.
  • Enhanced security: stronger encryption standards require longer key lengths and more secure algorithms.
  • Compliance with high-security standards: for example in healthcare, telco, and finance the data sensitivity is high, and availability of strong cryptography is critical.

Typically, FUTURE is suitable for environments handling highly sensitive data, preparing for future regulations, or adopting long-term security strategies.

Warning

Legacy systems or software does not have to support the more modern and stricter algorithms and protocols enforced by the FUTURE policy. For example, older systems might not support TLS 1.3 or larger key sizes. This could lead to compatibility problems.

Also, using strong algorithms usually increases the computational workload, which could negatively affect your system performance.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure cryptographic policies
  hosts: managed-node-01.example.com
  tasks:
    - name: Configure the FUTURE cryptographic security policy on the managed node
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.crypto_policies
      vars:
        - crypto_policies_policy: FUTURE
        - crypto_policies_reboot_ok: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    crypto_policies_policy: FUTURE
    Configures the required cryptographic policy (FUTURE) on the managed node. It can be either the base policy or a base policy with some sub-policies. The specified base policy and sub-policies have to be available on the managed node. The default value is null. It means that the configuration is not changed and the crypto_policies RHEL system role will only collect the Ansible facts.
    crypto_policies_reboot_ok: true
    Causes the system to reboot after the cryptographic policy change to make sure all of the services and applications will read the new configuration files. The default value is false.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.crypto_policies/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap
Warning

Because the FIPS:OSPP system-wide subpolicy contains further restrictions for cryptographic algorithms required by the Common Criteria (CC) certification, the system is less interoperable after you set it. For example, you cannot use RSA and DH keys shorter than 3072 bits, additional SSH algorithms, and several TLS groups. Setting FIPS:OSPP also prevents connecting to Red Hat Content Delivery Network (CDN) structure. Furthermore, you cannot integrate Active Directory (AD) into the IdM deployments that use FIPS:OSPP, communication between RHEL hosts using FIPS:OSPP and AD domains might not work, or some AD accounts might not be able to authenticate.

Note that your system is not CC-compliant after you set the FIPS:OSPP cryptographic subpolicy. The only correct way to make your RHEL system compliant with the CC standard is by following the guidance provided in the cc-config package. See the Common Criteria section on the Product compliance Red Hat Customer Portal page for a list of certified RHEL versions, validation reports, and links to CC guides hosted at the National Information Assurance Partnership (NIAP) website.

Verification

  1. On the control node, create another playbook named, for example, verify_playbook.yml: 

    ---
- name: Verification
  hosts: managed-node-01.example.com
  tasks:
    - name: Verify active cryptographic policy
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.crypto_policies
    - name: Display the currently active cryptographic policy
      ansible.builtin.debug:
        var: crypto_policies_active
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    crypto_policies_active
    An exported Ansible fact that contains the currently active policy name in the format as accepted by the crypto_policies_policy variable.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/verify_playbook.yml
    Copy to Clipboard Toggle word wrap

  3. Run the playbook: 

    $ ansible-playbook ~/verify_playbook.yml
TASK [debug] **************************
ok: [host] => {
    "crypto_policies_active": "FUTURE"
}
    Copy to Clipboard Toggle word wrap

    The crypto_policies_active variable shows the active policy on the managed node.

By using the fapolicyd software framework, you can restrict the execution of applications based on a user-defined policy and the framework verifies the integrity of applications before execution. You can automate the configuration of fapolicyd by using the fapolicyd RHEL system role.

Important

The fapolicyd service prevents only the execution of unauthorized applications that run as regular users, and not as root.

You can automate the installation and configuration of the fapolicyd service by using the fapolicyd RHEL system role.

With this role, you can remotely configure the service to allow users to execute only trusted applications, for example, the ones which are listed in the RPM database and in an allow list. Additionally, the service can perform integrity checks before it executes an allowed application.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configuring fapolicyd
  hosts: managed-node-01.example.com
  tasks:
    - name: Allow only executables installed from RPM database and specific files
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.fapolicyd
      vars:
        fapolicyd_setup_permissive: false
        fapolicyd_setup_integrity: sha256
        fapolicyd_setup_trust: rpmdb,file
        fapolicyd_add_trusted_file:
          - <path_to_allowed_command>
          - <path_to_allowed_service>
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    fapolicyd_setup_permissive: <true|false>
    Enables or disables sending policy decisions to the kernel for enforcement. Set this variable for debugging and testing purposes to false.
    fapolicyd_setup_integrity: <type_type>

    Defines the integrity checking method. You can set one of the following values:

    • none (default): Disables integrity checking.
    • size: The service compares only the file sizes of allowed applications.
    • ima: The service checks the SHA-256 hash that the kernel’s Integrity Measurement Architecture (IMA) stored in a file’s extended attribute. Additionally, the service performs a size check. Note that the role does not configure the IMA kernel subsystem. To use this option, you must manually configure the IMA subsystem.
    • sha256: The service compares the SHA-256 hash of allowed applications.
    fapolicyd_setup_trust: <trust_backends>
    Defines the list of trust backends. If you include the file backend, specify the allowed executable files in the fapolicyd_add_trusted_file list.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.fapolicyd.README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook ~/playbook.yml --syntax-check
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Execute a binary application that is not on the allow list as a user: 

    $ ansible managed-node-01.example.com -m command -a 'su -c "/bin/not_authorized_application " <user_name>'
bash: line 1: /bin/not_authorized_application: Operation not permitted non-zero return code
    Copy to Clipboard Toggle word wrap

RHEL system roles is a set of contents for the Ansible automation utility. This content together with the Ansible automation utility provides a consistent configuration interface to remotely manage multiple systems at once.

The rhel-system-roles package contains the rhel-system-roles.firewall RHEL system role. This role was introduced for automated configurations of the firewalld service.

With the firewall RHEL system role you can configure many different firewalld parameters, for example:

  • Zones
  • The services for which packets should be allowed
  • Granting, rejection, or dropping of traffic access to ports
  • Forwarding of ports or port ranges for a zone

The firewall RHEL system role supports automating a reset of firewalld settings to their defaults. This efficiently removes insecure or unintentional firewall rules and simplifies management.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Reset firewalld example
  hosts: managed-node-01.example.com
  tasks:
    - name: Reset firewalld
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.firewall
      vars:
        firewall:
          - previous: replaced
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    previous: replaced

    Removes all existing user-defined settings and resets the firewalld settings to defaults. If you combine the previous:replaced parameter with other settings, the firewall role removes all existing settings before applying new ones.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.firewall/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Run this command on the control node to remotely check that all firewall configuration on your managed node was reset to its default values: 

    # ansible managed-node-01.example.com -m ansible.builtin.command -a 'firewall-cmd --list-all-zones'
    Copy to Clipboard Toggle word wrap

You can use the firewall RHEL system role to remotely configure forwarding of incoming traffic from one local port to a different local port.

For example, if you have an environment where multiple services co-exist on the same machine and need the same default port, there are likely to become port conflicts. These conflicts can disrupt services and cause a downtime. With the firewall RHEL system role, you can efficiently forward traffic to alternative ports to ensure that your services can run simultaneously without modification to their configuration.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure firewalld
  hosts: managed-node-01.example.com
  tasks:
    - name: Forward incoming traffic on port 8080 to 443
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.firewall
      vars:
        firewall:
          - forward_port: 8080/tcp;443;
            state: enabled
            runtime: true
            permanent: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    forward_port: 8080/tcp;443
    Traffic coming to the local port 8080 using the TCP protocol is forwarded to the port 443.
    runtime: true

    Enables changes in the runtime configuration. The default is set to true.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.firewall/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • On the control node, run the following command to remotely check the forwarded-ports on your managed node: 

    # ansible managed-node-01.example.com -m ansible.builtin.command -a 'firewall-cmd --list-forward-ports'
managed-node-01.example.com | CHANGED | rc=0 >>
port=8080:proto=tcp:toport=443:toaddr=
    Copy to Clipboard Toggle word wrap

You can use the firewall RHEL system role to configure zone to allow certain traffic. For example, you can configure that the dmz zone with the enp1s0 interface allows HTTPS traffic to enable external users to access your web servers.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure firewalld
  hosts: managed-node-01.example.com
  tasks:
    - name: Creating a DMZ with access to HTTPS port and masquerading for hosts in DMZ
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.firewall
      vars:
        firewall:
          - zone: dmz
            interface: enp1s0
            service: https
            state: enabled
            runtime: true
            permanent: true
    Copy to Clipboard Toggle word wrap

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.firewall/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • On the control node, run the following command to remotely check the information about the dmz zone on your managed node: 

    # ansible managed-node-01.example.com -m ansible.builtin.command -a 'firewall-cmd --zone=dmz --list-all'
managed-node-01.example.com | CHANGED | rc=0 >>
dmz (active)
  target: default
  icmp-block-inversion: no
  interfaces: enp1s0
  sources:
  services: https ssh
  ports:
  protocols:
  forward: no
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
    Copy to Clipboard Toggle word wrap

With the ha_cluster system role, you can configure and manage a high-availability cluster that uses the Pacemaker high availability cluster resource manager.

11.1. Variables of the ha_cluster RHEL system role
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In an ha_cluster RHEL system role playbook, you define the variables for a high availability cluster according to the requirements of your cluster deployment.

The variables you can set for an ha_cluster RHEL system role are as follows:

ha_cluster_enable_repos
A boolean flag that enables the repositories containing the packages that are needed by the ha_cluster RHEL system role. When this variable is set to true, the default value, you must have active subscription coverage for RHEL and the RHEL High Availability Add-On on the systems that you will use as your cluster members or the system role will fail.
ha_cluster_enable_repos_resilient_storage
(RHEL 9.4 and later) A boolean flag that enables the repositories containing resilient storage packages, such as dlm or gfs2. For this option to take effect, ha_cluster_enable_repos must be set to true. The default value of this variable is false.
ha_cluster_manage_firewall

(RHEL 9.2 and later) A boolean flag that determines whether the ha_cluster RHEL system role manages the firewall. When ha_cluster_manage_firewall is set to true, the firewall high availability service and the fence-virt port are enabled. When ha_cluster_manage_firewall is set to false, the ha_cluster RHEL system role does not manage the firewall. If your system is running the firewalld service, you must set the parameter to true in your playbook.

You can use the ha_cluster_manage_firewall parameter to add ports, but you cannot use the parameter to remove ports. To remove ports, use the firewall system role directly.

In RHEL 9.2 and later, the firewall is no longer configured by default, because it is configured only when ha_cluster_manage_firewall is set to true.

ha_cluster_manage_selinux

(RHEL 9.2 and later) A boolean flag that determines whether the ha_cluster RHEL system role manages the ports belonging to the firewall high availability service using the selinux RHEL system role. When ha_cluster_manage_selinux is set to true, the ports belonging to the firewall high availability service are associated with the SELinux port type cluster_port_t. When ha_cluster_manage_selinux is set to false, the ha_cluster RHEL system role does not manage SELinux.

If your system is running the selinux service, you must set this parameter to true in your playbook. Firewall configuration is a prerequisite for managing SELinux. If the firewall is not installed, the managing SELinux policy is skipped.

You can use the ha_cluster_manage_selinux parameter to add policy, but you cannot use the parameter to remove policy. To remove policy, use the selinux RHEL system role directly.

ha_cluster_cluster_present

A boolean flag which, if set to true, determines that HA cluster will be configured on the hosts according to the variables passed to the role. Any cluster configuration not specified in the playbook and not supported by the role will be lost.

If ha_cluster_cluster_present is set to false, all HA cluster configuration will be removed from the target hosts.

The default value of this variable is true.

The following example playbook removes all cluster configuration on node1 and node2 

- hosts: node1 node2
  vars:
    ha_cluster_cluster_present: false

  roles:
    - rhel-system-roles.ha_cluster
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ha_cluster_start_on_boot
A boolean flag that determines whether cluster services will be configured to start on boot. The default value of this variable is true.
ha_cluster_install_cloud_agents
(RHEL 9.5 and later) A boolean flag that determines whether resource and fence agents for cloud environments are installed. These agents are not installed by default. Alternately, you can specify the packages for cloud environments by using the ha_cluster_fence_agent_packages and ha_cluster_extra_packages variables. The default value of this variable is false.
ha_cluster_fence_agent_packages
List of fence agent packages to install. The default value of this variable is fence-agents-all, fence-virt.
ha_cluster_extra_packages

List of additional packages to be installed. The default value of this variable is no packages.

This variable can be used to install additional packages not installed automatically by the role, for example custom resource agents.

It is possible to specify fence agents as members of this list. However, ha_cluster_fence_agent_packages is the recommended role variable to use for specifying fence agents, so that its default value is overridden.

ha_cluster_hacluster_password
A string value that specifies the password of the hacluster user. The hacluster user has full access to a cluster. To protect sensitive data, vault encrypt the password, as described in Encrypting content with Ansible Vault. There is no default password value, and this variable must be specified.
ha_cluster_hacluster_qdevice_password
(RHEL 9.3 and later) A string value that specifies the password of the hacluster user for a quorum device. This parameter is needed only if the ha_cluster_quorum parameter is configured to use a quorum device of type net and the password of the hacluster user on the quorum device is different from the password of the hacluster user specified with the ha_cluster_hacluster_password parameter. The hacluster user has full access to a cluster. To protect sensitive data, vault encrypt the password, as described in Encrypting content with Ansible Vault. There is no default value for this password.
ha_cluster_corosync_key_src

The path to Corosync authkey file, which is the authentication and encryption key for Corosync communication. It is highly recommended that you have a unique authkey value for each cluster. The key should be 256 bytes of random data.

If you specify a key for this variable, it is recommended that you vault encrypt the key, as described in Encrypting content with Ansible Vault.

If no key is specified, a key already present on the nodes will be used. If nodes do not have the same key, a key from one node will be distributed to other nodes so that all nodes have the same key. If no node has a key, a new key will be generated and distributed to the nodes.

If this variable is set, ha_cluster_regenerate_keys is ignored for this key.

The default value of this variable is null.

ha_cluster_pacemaker_key_src

The path to the Pacemaker authkey file, which is the authentication and encryption key for Pacemaker communication. It is highly recommended that you have a unique authkey value for each cluster. The key should be 256 bytes of random data.

If you specify a key for this variable, it is recommended that you vault encrypt the key, as described in Encrypting content with Ansible Vault.

If no key is specified, a key already present on the nodes will be used. If nodes do not have the same key, a key from one node will be distributed to other nodes so that all nodes have the same key. If no node has a key, a new key will be generated and distributed to the nodes.

If this variable is set, ha_cluster_regenerate_keys is ignored for this key.

The default value of this variable is null.

ha_cluster_fence_virt_key_src

The path to the fence-virt or fence-xvm pre-shared key file, which is the location of the authentication key for the fence-virt or fence-xvm fence agent.

If you specify a key for this variable, it is recommended that you vault encrypt the key, as described in Encrypting content with Ansible Vault.

If no key is specified, a key already present on the nodes will be used. If nodes do not have the same key, a key from one node will be distributed to other nodes so that all nodes have the same key. If no node has a key, a new key will be generated and distributed to the nodes. If the ha_cluster RHEL system role generates a new key in this fashion, you should copy the key to your nodes' hypervisor to ensure that fencing works.

If this variable is set, ha_cluster_regenerate_keys is ignored for this key.

The default value of this variable is null.

ha_cluster_pcsd_public_key_srcr, ha_cluster_pcsd_private_key_src

The path to the pcsd TLS certificate and private key. If this is not specified, a certificate-key pair already present on the nodes will be used. If a certificate-key pair is not present, a random new one will be generated.

If you specify a private key value for this variable, it is recommended that you vault encrypt the key, as described in Encrypting content with Ansible Vault.

If these variables are set, ha_cluster_regenerate_keys is ignored for this certificate-key pair.

The default value of these variables is null.

ha_cluster_pcsd_certificates

(RHEL 9.2 and later) Creates a pcsd private key and certificate using the certificate RHEL system role.

If your system is not configured with a pcsd private key and certificate, you can create them in one of two ways:

  • Set the ha_cluster_pcsd_certificates variable. When you set the ha_cluster_pcsd_certificates variable, the certificate RHEL system role is used internally and it creates the private key and certificate for pcsd as defined.
  • Do not set the ha_cluster_pcsd_public_key_src, ha_cluster_pcsd_private_key_src, or the ha_cluster_pcsd_certificates variables. If you do not set any of these variables, the ha_cluster RHEL system role will create pcsd certificates by means of pcsd itself. The value of ha_cluster_pcsd_certificates is set to the value of the variable certificate_requests as specified in the certificate RHEL system role. For more information about the certificate RHEL system role, see Requesting certificates using RHEL system roles.

The following operational considerations apply to the use of the ha_cluster_pcsd_certificate variable:

  • Unless you are using IPA and joining the systems to an IPA domain, the certificate RHEL system role creates self-signed certificates. In this case, you must explicitly configure trust settings outside of the context of RHEL system roles. System roles do not support configuring trust settings.
  • When you set the ha_cluster_pcsd_certificates variable, do not set the ha_cluster_pcsd_public_key_src and ha_cluster_pcsd_private_key_src variables.
  • When you set the ha_cluster_pcsd_certificates variable, ha_cluster_regenerate_keys is ignored for this certificate - key pair.

The default value of this variable is [].

For an example ha_cluster RHEL system role playbook that creates TLS certificates and key files in a high availability cluster, see Creating pcsd TLS certificates and key files for a high availability cluster.

ha_cluster_regenerate_keys
A boolean flag which, when set to true, determines that pre-shared keys and TLS certificates will be regenerated. For more information about when keys and certificates will be regenerated, see the descriptions of the ha_cluster_corosync_key_src, ha_cluster_pacemaker_key_src, ha_cluster_fence_virt_key_src, ha_cluster_pcsd_public_key_src, and ha_cluster_pcsd_private_key_src variables.
The default value of this variable is false.
ha_cluster_pcs_permission_list

Configures permissions to manage a cluster using pcsd. The items you configure with this variable are as follows:

  • type - user or group
  • name - user or group name

  • allow_list - Allowed actions for the specified user or group:

    • read - View cluster status and settings
    • write - Modify cluster settings except permissions and ACLs
    • grant - Modify cluster permissions and ACLs
    • full - Unrestricted access to a cluster including adding and removing nodes and access to keys and certificates

The structure of the ha_cluster_pcs_permission_list variable and its default values are as follows: 

ha_cluster_pcs_permission_list:
  - type: group
    name: hacluster
    allow_list:
      - grant
      - read
      - write
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ha_cluster_cluster_name
The name of the cluster. This is a string value with a default of my-cluster.
ha_cluster_transport

(RHEL 9.1 and later) Sets the cluster transport method. The items you configure with this variable are as follows:

  • type (optional) - Transport type: knet, udp, or udpu. The udp and udpu transport types support only one link. Encryption is always disabled for udp and udpu. Defaults to knet if not specified.
  • options (optional) - List of name-value dictionaries with transport options.
  • links (optional) - List of list of name-value dictionaries. Each list of name-value dictionaries holds options for one Corosync link. It is recommended that you set the linknumber value for each link. Otherwise, the first list of dictionaries is assigned by default to the first link, the second one to the second link, and so on.
  • compression (optional) - List of name-value dictionaries configuring transport compression. Supported only with the knet transport type.
  • crypto (optional) - List of name-value dictionaries configuring transport encryption. By default, encryption is enabled. Supported only with the knet transport type.

For a list of allowed options, see the pcs -h cluster setup help page or the setup description in the cluster section of the pcs(8) man page. For more detailed descriptions, see the corosync.conf(5) man page.

The structure of the ha_cluster_transport variable is as follows: 

ha_cluster_transport:
  type: knet
  options:
    - name: option1_name
      value: option1_value
    - name: option2_name
      value: option2_value
  links:
    -
      - name: option1_name
        value: option1_value
      - name: option2_name
        value: option2_value
    -
      - name: option1_name
        value: option1_value
      - name: option2_name
        value: option2_value
  compression:
    - name: option1_name
      value: option1_value
    - name: option2_name
      value: option2_value
  crypto:
    - name: option1_name
      value: option1_value
    - name: option2_name
      value: option2_value
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For an example ha_cluster RHEL system role playbook that configures a transport method, see Configuring Corosync values in a high availability cluster.

ha_cluster_totem

(RHEL 9.1 and later) Configures Corosync totem. For a list of allowed options, see the pcs -h cluster setup help page or the setup description in the cluster section of the pcs(8) man page. For a more detailed description, see the corosync.conf(5) man page.

The structure of the ha_cluster_totem variable is as follows: 

ha_cluster_totem:
  options:
    - name: option1_name
      value: option1_value
    - name: option2_name
      value: option2_value
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For an example ha_cluster RHEL system role playbook that configures a Corosync totem, see Configuring Corosync values in a high availability cluster.

ha_cluster_quorum

(RHEL 9.1 and later) Configures cluster quorum. You can configure the following items for cluster quorum:

  • options (optional) - List of name-value dictionaries configuring quorum. Allowed options are: auto_tie_breaker, last_man_standing, last_man_standing_window, and wait_for_all. For information about quorum options, see the votequorum(5) man page.

  • device (optional) - (RHEL 9.2 and later) Configures the cluster to use a quorum device. By default, no quorum device is used.

    • model (mandatory) - Specifies a quorum device model. Only net is supported

    • model_options (optional) - List of name-value dictionaries configuring the specified quorum device model. For model net, you must specify host and algorithm options.

      Use the pcs-address option to set a custom pcsd address and port to connect to the qnetd host. If you do not specify this option, the role connects to the default pcsd port on the host.

    • generic_options (optional) - List of name-value dictionaries setting quorum device options that are not model specific.

    • heuristics_options (optional) - List of name-value dictionaries configuring quorum device heuristics.

      For information about quorum device options, see the corosync-qdevice(8) man page. The generic options are sync_timeout and timeout. For model net options see the quorum.device.net section. For heuristics options, see the quorum.device.heuristics section.

      To regenerate a quorum device TLS certificate, set the ha_cluster_regenerate_keys variable to true.

The structure of the ha_cluster_quorum variable is as follows: 

ha_cluster_quorum:
  options:
    - name: option1_name
      value: option1_value
    - name: option2_name
      value: option2_value
  device:
    model: string
    model_options:
      - name: option1_name
        value: option1_value
      - name: option2_name
        value: option2_value
    generic_options:
      - name: option1_name
        value: option1_value
      - name: option2_name
        value: option2_value
    heuristics_options:
      - name: option1_name
        value: option1_value
      - name: option2_name
        value: option2_value
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For an example ha_cluster RHEL system role playbook that configures cluster quorum, see Configuring Corosync values in a high availability cluster. For an example ha_cluster RHEL system role playbook that configures a cluster using a quorum device, see Configuring a high availability cluster using a quorum device.

ha_cluster_sbd_enabled
(RHEL 9.1 and later) A boolean flag which determines whether the cluster can use the SBD node fencing mechanism. The default value of this variable is false. For example ha_cluster system role playbooks that enable SBD, see Configuring a high availability cluster with SBD node fencing by using the ha_cluster_node_options variable and Configuring a high availability cluster with SBD node fencing by using the ha_cluster variable.
ha_cluster_sbd_options

(RHEL 9.1 and later) List of name-value dictionaries specifying SBD options. For information about these options, see the Configuration via environment section of the sbd(8) man page.

Supported options are:

  • delay-start - defaults to false, documented as SBD_DELAY_START
  • startmode - defaults to always, documented as SBD_START_MODE
  • timeout-action - defaults to flush,reboot, documented as SBD_TIMEOUT_ACTION
  • watchdog-timeout - defaults to 5, documented as SBD_WATCHDOG_TIMEOUT

Watchdog and SBD devices can be configured on a node to node basis in one of two variables:

ha_cluster_cluster_properties

List of sets of cluster properties for Pacemaker cluster-wide configuration. Only one set of cluster properties is supported.

The structure of a set of cluster properties is as follows: 

ha_cluster_cluster_properties:
  - attrs:
      - name: property1_name
        value: property1_value
      - name: property2_name
        value: property2_value
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By default, no properties are set.

The following example playbook configures a cluster consisting of node1 and node2 and sets the stonith-enabled and no-quorum-policy cluster properties. 

- hosts: node1 node2
  vars:
    ha_cluster_cluster_name: my-new-cluster
    ha_cluster_hacluster_password: password
    ha_cluster_cluster_properties:
      - attrs:
          - name: stonith-enabled
            value: 'true'
          - name: no-quorum-policy
            value: stop

  roles:
    - rhel-system-roles.ha_cluster
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ha_cluster_node_options

(RHEL 9.4 and later) This variable defines settings which vary from one cluster node to another. It sets the options for the specified nodes, but does not specify which nodes form the cluster. You specify which nodes form the cluster with the hosts parameter in an inventory or a playbook.

The items you configure with this variable are as follows:

  • node_name (mandatory) - Name of the node for which to define Pacemaker node attributes. It must match a name defined for a node.
  • pcs_address (optional) - (RHEL 9.5 and later) Address used by pcs to communicate with the node. You can specify a name, a FQDN or an IP address. You can specify a port as well.
  • corosync_addresses (optional) - (RHEL 9.5 and later) List of addresses used by Corosync. All nodes must have the same number of addresses. The order of the addresses must be the same for all nodes, so that the addresses belonging to a particular link are specified in the same position for all nodes.
  • sbd_watchdog_modules (optional) - (RHEL 9.5 and later) Watchdog kernel modules to be loaded, which create /dev/watchdog* devices. Defaults to an empty list if not set.
  • sbd_watchdog_modules_blocklist (optional) - (RHEL 9.5 and later) Watchdog kernel modules to be unloaded and blocked. Defaults to an empty list if not set.
  • sbd_watchdog (optional) - (RHEL 9.5 and later) Watchdog device to be used by SBD. Defaults to /dev/watchdog if not set.
  • sbd_devices (optional) - (RHEL 9.5 and later) Devices to use for exchanging SBD messages and for monitoring. Defaults to an empty list if not set. Always refer to the devices using the long, stable device name (/dev/disk/by-id/).
  • attributes (optional) - List of sets of Pacemaker node attributes for the node. Currently, only one set is supported. The first set is used and the rest are ignored.
  • utilization (optional) - (RHEL 9.5 and later) List of sets of the node’s utilization. The field value must be an integer. Currently, only one set is supported. The first set is used and the rest are ignored.

The structure of the ha_cluster_node_options variable is as follows: 

ha_cluster_node_options:
  - node_name: node1
    pcs_address: node1-address
    corosync_addresses:
      - 192.168.1.11
      - 192.168.2.11
    sbd_watchdog_modules:
      - module1
      - module2
    sbd_watchdog_modules_blocklist:
      - module3
    sbd_watchdog: /dev/watchdog2
    sbd_devices:
      - /dev/disk/by-id/000001
      - /dev/disk/by-id/000002
      - /dev/disk/by-id/000003
    attributes:
      - attrs:
          - name: attribute1
            value: value1_node1
          - name: attribute2
            value: value2_node1
    utilization:
      - attrs:
          - name: utilization1
            value: value1_node1
          - name: utilization2
            value: value2_node1
  - node_name: node2
    pcs_address: node2-address:2224
    corosync_addresses:
      - 192.168.1.12
      - 192.168.2.12
    sbd_watchdog_modules:
      - module1
    sbd_watchdog_modules_blocklist:
      - module3
    sbd_watchdog: /dev/watchdog1
    sbd_devices:
      - /dev/disk/by-id/000001
      - /dev/disk/by-id/000002
      - /dev/disk/by-id/000003
    attributes:
      - attrs:
          - name: attribute1
            value: value1_node2
          - name: attribute2
            value: value2_node2
    utilization:
      - attrs:
          - name: utilization1
            value: value1_node2
          - name: utilization2
            value: value2_node2
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By default, no node options are defined.

For an example ha_cluster RHEL system role playbook that includes node options configuration, see Configuring a high availability cluster with node attributes.

ha_cluster_resource_primitives

This variable defines pacemaker resources configured by the RHEL system role, including fencing resources. You can configure the following items for each resource:

  • id (mandatory) - ID of a resource.
  • agent (mandatory) - Name of a resource or fencing agent, for example ocf:pacemaker:Dummy or stonith:fence_xvm. It is mandatory to specify stonith: for STONITH agents. For resource agents, it is possible to use a short name, such as Dummy, instead of ocf:pacemaker:Dummy. However, if several agents with the same short name are installed, the role will fail as it will be unable to decide which agent should be used. Therefore, it is recommended that you use full names when specifying a resource agent.
  • instance_attrs (optional) - List of sets of the resource’s instance attributes. Currently, only one set is supported. The exact names and values of attributes, as well as whether they are mandatory or not, depend on the resource or fencing agent.
  • meta_attrs (optional) - List of sets of the resource’s meta attributes. Currently, only one set is supported.
  • copy_operations_from_agent (optional) - (RHEL 9.3 and later) Resource agents usually define default settings for resource operations, such as interval and timeout, optimized for the specific agent. If this variable is set to true, then those settings are copied to the resource configuration. Otherwise, clusterwide defaults apply to the resource. If you also define resource operation defaults for the resource with the ha_cluster_resource_operation_defaults role variable, you can set this to false. The default value of this variable is true.

  • operations (optional) - List of the resource’s operations.

    • action (mandatory) - Operation action as defined by pacemaker and the resource or fencing agent.
    • attrs (mandatory) - Operation options, at least one option must be specified. (RHEL 9.5 and later)
  • utilization (optional) - List of sets of the resource’s utilization. The value field must be an integer. Only one set is supported, so the first set is used and the rest are ignored.

The structure of the resource definition that you configure with the ha_cluster RHEL system role is as follows: 

  - id: resource-id
    agent: resource-agent
    instance_attrs:
      - attrs:
          - name: attribute1_name
            value: attribute1_value
          - name: attribute2_name
            value: attribute2_value
    meta_attrs:
      - attrs:
          - name: meta_attribute1_name
            value: meta_attribute1_value
          - name: meta_attribute2_name
            value: meta_attribute2_value
    copy_operations_from_agent: bool
    operations:
      - action: operation1-action
        attrs:
          - name: operation1_attribute1_name
            value: operation1_attribute1_value
          - name: operation1_attribute2_name
            value: operation1_attribute2_value
      - action: operation2-action
        attrs:
          - name: operation2_attribute1_name
            value: operation2_attribute1_value
          - name: operation2_attribute2_name
            value: operation2_attribute2_value
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By default, no resources are defined.

For an example ha_cluster RHEL system role playbook that includes resource configuration, see Configuring a high availability cluster with fencing and resources.

ha_cluster_resource_groups

This variable defines pacemaker resource groups configured by the system role. You can configure the following items for each resource group:

  • id (mandatory) - ID of a group.
  • resources (mandatory) - List of the group’s resources. Each resource is referenced by its ID and the resources must be defined in the ha_cluster_resource_primitives variable. At least one resource must be listed.
  • meta_attrs (optional) - List of sets of the group’s meta attributes. Currently, only one set is supported.

The structure of the resource group definition that you configure with the ha_cluster RHEL system role is as follows: 

ha_cluster_resource_groups:
  - id: group-id
    resource_ids:
      - resource1-id
      - resource2-id
    meta_attrs:
      - attrs:
          - name: group_meta_attribute1_name
            value: group_meta_attribute1_value
          - name: group_meta_attribute2_name
            value: group_meta_attribute2_value
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By default, no resource groups are defined.

For an example ha_cluster RHEL system role playbook that includes resource group configuration, see Configuring a high availability cluster with fencing and resources.

ha_cluster_resource_clones

This variable defines pacemaker resource clones configured by the system role. You can configure the following items for a resource clone:

  • resource_id (mandatory) - Resource to be cloned. The resource must be defined in the ha_cluster_resource_primitives variable or the ha_cluster_resource_groups variable.
  • promotable (optional) - Indicates whether the resource clone to be created is a promotable clone, indicated as true or false.
  • id (optional) - Custom ID of the clone. If no ID is specified, it will be generated. A warning will be displayed if this option is not supported by the cluster.
  • meta_attrs (optional) - List of sets of the clone’s meta attributes. Currently, only one set is supported.

The structure of the resource clone definition that you configure with the ha_cluster RHEL system role is as follows: 

ha_cluster_resource_clones:
  - resource_id: resource-to-be-cloned
    promotable: true
    id: custom-clone-id
    meta_attrs:
      - attrs:
          - name: clone_meta_attribute1_name
            value: clone_meta_attribute1_value
          - name: clone_meta_attribute2_name
            value: clone_meta_attribute2_value
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By default, no resource clones are defined.

For an example ha_cluster RHEL system role playbook that includes resource clone configuration, see Configuring a high availability cluster with fencing and resources.

ha_cluster_resource_defaults

(RHEL 9.3 and later) This variable defines sets of resource defaults. You can define multiple sets of defaults and apply them to resources of specific agents using rules. The defaults you specify with the ha_cluster_resource_defaults variable do not apply to resources which override them with their own defined values.

Only meta attributes can be specified as defaults.

You can configure the following items for each defaults set:

  • id (optional) - ID of the defaults set. If not specified, it is autogenerated.
  • rule (optional) - Rule written using pcs syntax defining when and for which resources the set applies. For information on specifying a rule, see the resource defaults set create section of the pcs(8) man page.
  • score (optional) - Weight of the defaults set.
  • attrs (optional) - Meta attributes applied to resources as defaults.

The structure of the ha_cluster_resource_defaults variable is as follows: 

ha_cluster_resource_defaults:
  meta_attrs:
    - id: defaults-set-1-id
      rule: rule-string
      score: score-value
      attrs:
        - name: meta_attribute1_name
          value: meta_attribute1_value
        - name: meta_attribute2_name
          value: meta_attribute2_value
    - id: defaults-set-2-id
      rule: rule-string
      score: score-value
      attrs:
        - name: meta_attribute3_name
          value: meta_attribute3_value
        - name: meta_attribute4_name
          value: meta_attribute4_value
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For an example ha_cluster RHEL system role playbook that configures resource defaults, see Configuring a high availability cluster with resource and resource operation defaults.

ha_cluster_resource_operation_defaults

(RHEL 9.3 and later) This variable defines sets of resource operation defaults. You can define multiple sets of defaults and apply them to resources of specific agents and specific resource operations using rules. The defaults you specify with the ha_cluster_resource_operation_defaults variable do not apply to resource operations which override them with their own defined values. By default, the ha_cluster RHEL system role configures resources to define their own values for resource operations. For information about overriding these defaults with the ha_cluster_resource_operations_defaults variable, see the description of the copy_operations_from_agent item in ha_cluster_resource_primitives.

Only meta attributes can be specified as defaults.

The structure of the ha_cluster_resource_operations_defaults variable is the same as the structure for the ha_cluster_resource_defaults variable, with the exception of how you specify a rule. For information about specifying a rule to describe the resource operation to which a set applies, see the resource op defaults set create section of the pcs(8) man page.

ha_cluster_stonith_levels

(RHEL 9.4 and later) This variable defines STONITH levels, also known as fencing topology. Fencing levels configure a cluster to use multiple devices to fence nodes. You can define alternative devices in case one device fails and you can require multiple devices to all be executed successfully to consider a node successfully fenced. For more information on fencing levels, see Configuring fencing levels in Configuring and managing high availability clusters.

You can configure the following items when defining fencing levels:

  • level (mandatory) - Order in which to attempt the fencing level. Pacemaker attempts levels in ascending order until one succeeds.
  • target (optional) - Name of a node this level applies to.

  • You must specify one of the following three selections:

    • target_pattern - POSIX extended regular expression matching the names of the nodes this level applies to.
    • target_attribute - Name of a node attribute that is set for the node this level applies to.
    • target_attribute and target_value - Name and value of a node attribute that is set for the node this level applies to.

  • resouce_ids (mandatory) - List of fencing resources that must all be tried for this level.

    By default, no fencing levels are defined.

The structure of the fencing levels definition that you configure with the ha_cluster RHEL system role is as follows: 

ha_cluster_stonith_levels:
  - level: 1..9
    target: node_name
    target_pattern: node_name_regular_expression
    target_attribute: node_attribute_name
    target_value: node_attribute_value
    resource_ids:
      - fence_device_1
      - fence_device_2
  - level: 1..9
    target: node_name
    target_pattern: node_name_regular_expression
    target_attribute: node_attribute_name
    target_value: node_attribute_value
    resource_ids:
      - fence_device_1
      - fence_device_2
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For an example ha_cluster RHEL system role playbook that configures fencing defaults, see Configuring a high availability cluster with fencing levels.

ha_cluster_constraints_location

This variable defines resource location constraints. Resource location constraints indicate which nodes a resource can run on. You can specify a resources specified by a resource ID or by a pattern, which can match more than one resource. You can specify a node by a node name or by a rule.

You can configure the following items for a resource location constraint:

  • resource (mandatory) - Specification of a resource the constraint applies to.
  • node (mandatory) - Name of a node the resource should prefer or avoid.
  • id (optional) - ID of the constraint. If not specified, it will be autogenerated.

  • options (optional) - List of name-value dictionaries.

    • score - Sets the weight of the constraint.

      • A positive score value means the resource prefers running on the node.
      • A negative score value means the resource should avoid running on the node.
      • A score value of -INFINITY means the resource must avoid running on the node.
      • If score is not specified, the score value defaults to INFINITY.

By default no resource location constraints are defined.

The structure of a resource location constraint specifying a resource ID and node name is as follows: 

ha_cluster_constraints_location:
  - resource:
      id: resource-id
    node: node-name
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: option-name
        value: option-value
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The items that you configure for a resource location constraint that specifies a resource pattern are the same items that you configure for a resource location constraint that specifies a resource ID, with the exception of the resource specification itself. The item that you specify for the resource specification is as follows:

  • pattern (mandatory) - POSIX extended regular expression resource IDs are matched against.

The structure of a resource location constraint specifying a resource pattern and node name is as follows: 

ha_cluster_constraints_location:
  - resource:
      pattern: resource-pattern
    node: node-name
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: resource-discovery
        value: resource-discovery-value
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You can configure the following items for a resource location constraint that specifies a resource ID and a rule:

  • resource (mandatory) - Specification of a resource the constraint applies to.

    • id (mandatory) - Resource ID.
    • role (optional) - The resource role to which the constraint is limited: Started, Unpromoted, Promoted.
  • rule (mandatory) - Constraint rule written using pcs syntax. For further information, see the constraint location section of the pcs(8) man page.
  • Other items to specify have the same meaning as for a resource constraint that does not specify a rule.

The structure of a resource location constraint that specifies a resource ID and a rule is as follows: 

ha_cluster_constraints_location:
  - resource:
      id: resource-id
      role: resource-role
    rule: rule-string
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: resource-discovery
        value: resource-discovery-value
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The items that you configure for a resource location constraint that specifies a resource pattern and a rule are the same items that you configure for a resource location constraint that specifies a resource ID and a rule, with the exception of the resource specification itself. The item that you specify for the resource specification is as follows:

  • pattern (mandatory) - POSIX extended regular expression resource IDs are matched against.

The structure of a resource location constraint that specifies a resource pattern and a rule is as follows: 

ha_cluster_constraints_location:
  - resource:
      pattern: resource-pattern
      role: resource-role
    rule: rule-string
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: resource-discovery
        value: resource-discovery-value
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For an example ha_cluster RHEL system role playbook that creates a cluster with resource constraints, see Configuring a high availability cluster with resource constraints.

ha_cluster_constraints_colocation

This variable defines resource colocation constraints. Resource colocation constraints indicate that the location of one resource depends on the location of another one. There are two types of colocation constraints: a simple colocation constraint for two resources, and a set colocation constraint for multiple resources.

You can configure the following items for a simple resource colocation constraint:

  • resource_follower (mandatory) - A resource that should be located relative to resource_leader.

    • id (mandatory) - Resource ID.
    • role (optional) - The resource role to which the constraint is limited: Started, Unpromoted, Promoted.

  • resource_leader (mandatory) - The cluster will decide where to put this resource first and then decide where to put resource_follower.

    • id (mandatory) - Resource ID.
    • role (optional) - The resource role to which the constraint is limited: Started, Unpromoted, Promoted.
  • id (optional) - ID of the constraint. If not specified, it will be autogenerated.

  • options (optional) - List of name-value dictionaries.

    • score - Sets the weight of the constraint.

      • Positive score values indicate the resources should run on the same node.
      • Negative score values indicate the resources should run on different nodes.
      • A score value of +INFINITY indicates the resources must run on the same node.
      • A score value of -INFINITY indicates the resources must run on different nodes.
      • If score is not specified, the score value defaults to INFINITY.

By default no resource colocation constraints are defined.

The structure of a simple resource colocation constraint is as follows: 

ha_cluster_constraints_colocation:
  - resource_follower:
      id: resource-id1
      role: resource-role1
    resource_leader:
      id: resource-id2
      role: resource-role2
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: option-name
        value: option-value
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You can configure the following items for a resource set colocation constraint:

  • resource_sets (mandatory) - List of resource sets.

    • resource_ids (mandatory) - List of resources in a set.
    • options (optional) - List of name-value dictionaries fine-tuning how resources in the sets are treated by the constraint.
  • id (optional) - Same values as for a simple colocation constraint.
  • options (optional) - Same values as for a simple colocation constraint.

The structure of a resource set colocation constraint is as follows: 

ha_cluster_constraints_colocation:
  - resource_sets:
      - resource_ids:
          - resource-id1
          - resource-id2
        options:
          - name: option-name
            value: option-value
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: option-name
        value: option-value
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For an example ha_cluster RHEL system role playbook that creates a cluster with resource constraints, see Configuring a high availability cluster with resource constraints.

ha_cluster_constraints_order

This variable defines resource order constraints. Resource order constraints indicate the order in which certain resource actions should occur. There are two types of resource order constraints: a simple order constraint for two resources, and a set order constraint for multiple resources.

You can configure the following items for a simple resource order constraint:

  • resource_first (mandatory) - Resource that the resource_then resource depends on.

    • id (mandatory) - Resource ID.
    • action (optional) - The action that must complete before an action can be initiated for the resource_then resource. Allowed values: start, stop, promote, demote.

  • resource_then (mandatory) - The dependent resource.

    • id (mandatory) - Resource ID.
    • action (optional) - The action that the resource can execute only after the action on the resource_first resource has completed. Allowed values: start, stop, promote, demote.
  • id (optional) - ID of the constraint. If not specified, it will be autogenerated.
  • options (optional) - List of name-value dictionaries.

By default no resource order constraints are defined.

The structure of a simple resource order constraint is as follows: 

ha_cluster_constraints_order:
  - resource_first:
      id: resource-id1
      action: resource-action1
    resource_then:
      id: resource-id2
      action: resource-action2
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: option-name
        value: option-value
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You can configure the following items for a resource set order constraint:

  • resource_sets (mandatory) - List of resource sets.

    • resource_ids (mandatory) - List of resources in a set.
    • options (optional) - List of name-value dictionaries fine-tuning how resources in the sets are treated by the constraint.
  • id (optional) - Same values as for a simple order constraint.
  • options (optional) - Same values as for a simple order constraint.

The structure of a resource set order constraint is as follows: 

ha_cluster_constraints_order:
  - resource_sets:
      - resource_ids:
          - resource-id1
          - resource-id2
        options:
          - name: option-name
            value: option-value
    id: constraint-id
    options:
      - name: score
        value: score-value
      - name: option-name
        value: option-value
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For an example ha_cluster RHEL system role playbook that creates a cluster with resource constraints, see Configuring a high availability cluster with resource constraints.

ha_cluster_constraints_ticket

This variable defines resource ticket constraints. Resource ticket constraints indicate the resources that depend on a certain ticket. There are two types of resource ticket constraints: a simple ticket constraint for one resource, and a ticket order constraint for multiple resources.

You can configure the following items for a simple resource ticket constraint:

  • resource (mandatory) - Specification of a resource the constraint applies to.

    • id (mandatory) - Resource ID.
    • role (optional) - The resource role to which the constraint is limited: Started, Unpromoted, Promoted.
  • ticket (mandatory) - Name of a ticket the resource depends on.
  • id (optional) - ID of the constraint. If not specified, it will be autogenerated.

  • options (optional) - List of name-value dictionaries.

    • loss-policy (optional) - Action to perform on the resource if the ticket is revoked.

By default no resource ticket constraints are defined.

The structure of a simple resource ticket constraint is as follows: 

ha_cluster_constraints_ticket:
  - resource:
      id: resource-id
      role: resource-role
    ticket: ticket-name
    id: constraint-id
    options:
      - name: loss-policy
        value: loss-policy-value
      - name: option-name
        value: option-value
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You can configure the following items for a resource set ticket constraint:

  • resource_sets (mandatory) - List of resource sets.

    • resource_ids (mandatory) - List of resources in a set.
    • options (optional) - List of name-value dictionaries fine-tuning how resources in the sets are treated by the constraint.
  • ticket (mandatory) - Same value as for a simple ticket constraint.
  • id (optional) - Same value as for a simple ticket constraint.
  • options (optional) - Same values as for a simple ticket constraint.

The structure of a resource set ticket constraint is as follows: 

ha_cluster_constraints_ticket:
  - resource_sets:
      - resource_ids:
          - resource-id1
          - resource-id2
        options:
          - name: option-name
            value: option-value
    ticket: ticket-name
    id: constraint-id
    options:
      - name: option-name
        value: option-value
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For an example ha_cluster RHEL system role playbook that creates a cluster with resource constraints, see Configuring a high availability cluster with resource constraints.

ha_cluster_acls

(RHEL 9.5 and later) This variable defines ACL roles, users and groups.

You can configure the following items for acl_roles:

  • id (mandatory) - ID of an ACL role.
  • description (optional) - Description of the ACL role.

  • permissions (optional) - List of ACL role permissions.

    • kind (mandatory) - The access being granted. Allowed values are read, write, and deny.
    • xpath (optional) - An XPath specification selecting an XML element in the CIB to which the permission applies. It is mandatory to specify exactly one of the items: xpath or reference.
    • reference (optional) - The ID of an XML element in the CIB to which the permission applies. It is mandatory to specify exactly one of the items: xpath or reference. The ID must exist.

You can configure the following items for acl_users:

  • id (mandatory) - ID of an ACL user.
  • roles (optional) - List of ACL Role IDs assigned to the user.

You can configure the following items for acl_group:

  • id (mandatory) - ID of an ACL group.
  • roles (optional) - List of ACL Role IDs assigned to the group.

The structure of an ACL definition is as follows: 

ha_cluster_acls:
  acl_roles:
    - id: role-id-1
      description: role description
      permissions:
        - kind: access-type
          xpath: XPath expression
        - kind: access-type
          reference: cib-element-id
    - id: role-id-2
      permissions:
        - kind: access-type
          xpath: XPath expression
  acl_users:
    - id: user-name
      roles:
        - role-id-1
        - role-id-2
  acl_groups:
    - id: group-name
      roles:
        - role-id-2
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To enable ACLS in the cluster, you must configure the enable-acl cluster property: 

ha_cluster_cluster_properties:
  - attrs:
      - name: enable-acl
        value: 'true'
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For an example ha_cluster RHEL system role playbook that creates a cluster with ACL roles, users, and groups, see Configuring a high availability cluster that implements access control lists (ACLS) by using the RHEL system role.

ha_cluster_alerts

(RHEL 9.5 and later) This variable defines Pacemaker alerts.

Note

The ha_cluster role configures the cluster to call external programs to handle alerts. You must provide the programs and distribute them to cluster nodes.

You can configure the following items for alerts:

  • id (mandatory) - ID of an alert
  • ipath (mandatory) - Path to the alert agent executable.
  • description (optional) - Description of the alert.
  • instance_attrs (optional) - List of sets of the alert’s instance attributes.Only one set is supported. The first set is used and the rest are ignored.
  • meta_attrs (optional) - List of sets of the alert’s meta attributes. Only one set is supported. The first set is used and the rest are ignored. *recipients (optional) - List of alert’s recipients.

You can configure the following items for recipients:

  • value (mandatory) - Value of a recipient.
  • id (optional) - ID of the recipient.
  • description (optional) - Description of the recipient.
  • instance_attrs (optional) - List of sets of the recipient’s instance attributes. Only one set is supported. The first set is used and the rest are ignored.
  • meta_attrs (optional) - List of sets of the recipient’s meta attributes. Only one set is supported. The first set is used and the rest are ignored.

The structure of an alert definition is as follows: 

ha_cluster_alerts:
  - id: alert1
    path: /alert1/path
    description: Alert1 description
    instance_attrs:
      - attrs:
        - name: alert_attr1_name
          value: alert_attr1_value
    meta_attrs:
      - attrs:
        - name: alert_meta_attr1_name
          value: alert_meta_attr1_value
    recipients:
      - value: recipient_value
        id: recipient1
        description: Recipient1 description
        instance_attrs:
          - attrs:
            - name: recipient_attr1_name
              value: recipient_attr1_value
        meta_attrs:
          - attrs:
            - name: recipient_meta_attr1_name
              value: recipient_meta_attr1_value
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For an example ha_cluster RHEL system role playbook that configures a cluster with alerts, see Configuring alerts for a high availability cluster by using the ha_cluster RHEL system role.

ha_cluster_qnetd

(RHEL 9.2 and later) This variable configures a qnetd host which can then serve as an external quorum device for clusters.

You can configure the following items for a qnetd host:

  • present (optional) - If true, configure a qnetd instance on the host. If false, remove qnetd configuration from the host. The default value is false. If you set this true, you must set ha_cluster_cluster_present to false.
  • start_on_boot (optional) - Configures whether the qnetd instance should start automatically on boot. The default value is true.
  • regenerate_keys (optional) - Set this variable to true to regenerate the qnetd TLS certificate. If you regenerate the certificate, you must either re-run the role for each cluster to connect it to the qnetd host again or run pcs manually.

You cannot run qnetd on a cluster node because fencing would disrupt qnetd operation.

For an example ha_cluster RHEL system role playbook that configures a cluster using a quorum device, see Configuring a cluster using a quorum device.

When configuring an HA cluster using the ha_cluster RHEL system role playbook, you configure the names and addresses of the nodes for the cluster in an inventory.

For each node in an inventory, you can optionally specify the following items:

  • node_name - the name of a node in a cluster.
  • pcs_address - an address used by pcs to communicate with the node. It can be a name, FQDN or an IP address and it can include a port number.
  • corosync_addresses - list of addresses used by Corosync. All nodes which form a particular cluster must have the same number of addresses. The order of the addresses must be the same for all nodes, so that the addresses belonging to a particular link are specified in the same position for all nodes.

The following example shows an inventory with targets node1 and node2. node1 and node2 must be either fully qualified domain names or must otherwise be able to connect to the nodes as when, for example, the names are resolvable through the /etc/hosts file. 

all:
  hosts:
    node1:
      ha_cluster:
        node_name: node-A
        pcs_address: node1-address
        corosync_addresses:
          - 192.168.1.11
          - 192.168.2.11
    node2:
      ha_cluster:
        node_name: node-B
        pcs_address: node2-address:2224
        corosync_addresses:
          - 192.168.1.12
          - 192.168.2.12
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In RHEL 9.1 and later, you can optionally configure watchdog and SBD devices for each node in an inventory. All SBD devices must be shared to and accessible from all nodes. Watchdog devices can be different for each node as well. For an example procedure that configures SBD node fencing in an inventory file, see Configuring a high availability cluster with SBD node fencing by using the ha_cluster variable.

You can use the ha_cluster RHEL system role to create Transport Layer Security (TLS) certificates and key files in a high availability cluster. When you run this playbook, the ha_cluster RHEL system role uses the certificate RHEL system role internally to manage TLS certificates.

The connection between cluster nodes is secured using TLS encryption. By default, the pcsd daemon generates self-signed certificates. For many deployments, however, you may want to replace the default certificates with certificates issued by a certificate authority of your company and apply your company certificate policies for pcsd.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
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    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
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    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create a high availability cluster
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Create TLS certificates and key files in a high availability cluster
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: "{{ cluster_password }}"
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_pcsd_certificates:
          - name: FILENAME
            common_name: "{{ ansible_hostname }}"
            ca: self-sign
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    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_pcsd_certificates: <certificate_properties>
    A variable that creates a self-signed pcsd certificate and private key files in /var/lib/pcsd. In this example, the pcsd certificate has the file name FILENAME.crt and the key file is named FILENAME.key.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
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    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
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You can use the ha_cluster system role to configure a basic cluster in a simple, automatic way. Once you have created a basic cluster, you can use the pcs command-line interface to configure the other cluster components and behaviors on a resource-by-resource basis.

This example configures a basic two-node cluster with no fencing configured using the minimum required parameters.

Warning

The ha_cluster system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
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    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create a high availability cluster
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Create cluster with minimum required parameters and no fencing
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: "{{ cluster_password }}"
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
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    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

The specific components of a cluster configuration depend on your individual needs, which vary between sites. You can use the ha_cluster RHEL system role to configure a cluster with a fencing device, cluster resources, resource groups, and a cloned resource.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create a high availability cluster
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Create cluster with fencing and resources
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: "{{ cluster_password }}"
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_resource_primitives:
          - id: xvm-fencing
            agent: 'stonith:fence_xvm'
            instance_attrs:
              - attrs:
                  - name: pcmk_host_list
                    value: node1 node2
          - id: simple-resource
            agent: 'ocf:pacemaker:Dummy'
          - id: resource-with-options
            agent: 'ocf:pacemaker:Dummy'
            instance_attrs:
              - attrs:
                  - name: fake
                    value: fake-value
                  - name: passwd
                    value: passwd-value
            meta_attrs:
              - attrs:
                  - name: target-role
                    value: Started
                  - name: is-managed
                    value: 'true'
            operations:
              - action: start
                attrs:
                  - name: timeout
                    value: '30s'
              - action: monitor
                attrs:
                  - name: timeout
                    value: '5'
                  - name: interval
                    value: '1min'
          - id: dummy-1
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-2
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-3
            agent: 'ocf:pacemaker:Dummy'
          - id: simple-clone
            agent: 'ocf:pacemaker:Dummy'
          - id: clone-with-options
            agent: 'ocf:pacemaker:Dummy'
        ha_cluster_resource_groups:
          - id: simple-group
            resource_ids:
              - dummy-1
              - dummy-2
            meta_attrs:
              - attrs:
                  - name: target-role
                    value: Started
                  - name: is-managed
                    value: 'true'
          - id: cloned-group
            resource_ids:
              - dummy-3
        ha_cluster_resource_clones:
          - resource_id: simple-clone
          - resource_id: clone-with-options
            promotable: yes
            id: custom-clone-id
            meta_attrs:
              - attrs:
                  - name: clone-max
                    value: '2'
                  - name: clone-node-max
                    value: '1'
          - resource_id: cloned-group
            promotable: yes
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_resource_primitives: <cluster_resources>
    A list of resource definitions for the Pacemaker resources configured by the ha_cluster RHEL system role, including fencing
    ha_cluster_resource_groups: <resource_groups>
    A list of resource group definitions configured by the ha_cluster RHEL system role.
    ha_cluster_resource_clones: <resource_clones>
    A list of resource clone definitions configured by the ha_cluster RHEL system role.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

In your cluster configuration, you can change the Pacemaker default values of a resource option for all resources. You can also change the default value for all resource operations in the cluster.

For information about changing the default value of a resource option, see Changing the default value of a resource option. For information about global resource operation defaults, see Configuring global resource operation defaults.

The following example procedure uses the ha_cluster RHEL system role to create a high availability cluster that defines resource and resource operation defaults.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create a high availability cluster
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Create cluster with fencing and resource operation defaults
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: "{{ cluster_password }}"
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        # Set a different resource-stickiness value during
        # and outside work hours. This allows resources to
        # automatically move back to their most
        # preferred hosts, but at a time that
        # does not interfere with business activities.
        ha_cluster_resource_defaults:
          meta_attrs:
            - id: core-hours
              rule: date-spec hours=9-16 weekdays=1-5
              score: 2
              attrs:
                - name: resource-stickiness
                  value: INFINITY
            - id: after-hours
              score: 1
              attrs:
                - name: resource-stickiness
                  value: 0
        # Default the timeout on all 10-second-interval
        # monitor actions on IPaddr2 resources to 8 seconds.
        ha_cluster_resource_operation_defaults:
          meta_attrs:
            - rule: resource ::IPaddr2 and op monitor interval=10s
              score: INFINITY
              attrs:
                - name: timeout
                  value: 8s
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_resource_defaults: <resource_defaults>
    A variable that defines sets of resource defaults.
    ha_cluster_resource_operation_defaults: <resource_operation_defaults>
    A variable that defines sets of resource operation defaults.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the ha_cluster RHEL system role to configure high availability clusters with fencing levels. With multiple fencing devices for a node, you need to define fencing levels for those devices to determine the order that Pacemaker will use the devices to attempt to fence a node.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
fence1_password: <fence1_password>
fence2_password: <fence2_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml. This example playbook file configures a cluster running the firewalld and selinux services. 

    ---
- name: Create a high availability cluster
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Configure a cluster that defines fencing levels
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: "{{ cluster_password }}"
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_resource_primitives:
          - id: apc1
            agent: 'stonith:fence_apc_snmp'
            instance_attrs:
              - attrs:
                  - name: ip
                    value: apc1.example.com
                  - name: username
                    value: user
                  - name: password
                    value: "{{ fence1_password }}"
                  - name: pcmk_host_map
                    value: node1:1;node2:2
          - id: apc2
            agent: 'stonith:fence_apc_snmp'
            instance_attrs:
              - attrs:
                  - name: ip
                    value: apc2.example.com
                  - name: username
                    value: user
                  - name: password
                    value: "{{ fence2_password }}"
                  - name: pcmk_host_map
                    value: node1:1;node2:2
        # Nodes have redundant power supplies, apc1 and apc2. Cluster must
        # ensure that when attempting to reboot a node, both power
        # supplies # are turned off before either power supply is turned
        # back on.
        ha_cluster_stonith_levels:
          - level: 1
            target: node1
            resource_ids:
              - apc1
              - apc2
          - level: 1
            target: node2
            resource_ids:
              - apc1
              - apc2
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_resource_primitives: <cluster_resources>
    A list of resource definitions for the Pacemaker resources configured by the ha_cluster RHEL system role, including fencing
    ha_cluster_stonith_levels: <stonith_levels>
    A variable that defines STONITH levels, also known as fencing topology, which configure a cluster to use multiple devices to fence nodes.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

When configuring a cluster, you can specify the behavior of the cluster resources to be in line with your application requirements. You can control the behavior of cluster resources by configuring resource constraints.

You can define the following categories of resource constraints:

The following example procedure uses the ha_cluster RHEL system role to create a high availability cluster that includes resource location constraints, resource colocation constraints, resource order constraints, and resource ticket constraints.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create a high availability cluster
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Create cluster with resource constraints
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: "{{ cluster_password }}"
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        # In order to use constraints, we need resources
        # the constraints will apply to.
        ha_cluster_resource_primitives:
          - id: xvm-fencing
            agent: 'stonith:fence_xvm'
            instance_attrs:
              - attrs:
                  - name: pcmk_host_list
                    value: node1 node2
          - id: dummy-1
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-2
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-3
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-4
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-5
            agent: 'ocf:pacemaker:Dummy'
          - id: dummy-6
            agent: 'ocf:pacemaker:Dummy'
        # location constraints
        ha_cluster_constraints_location:
          # resource ID and node name
          - resource:
              id: dummy-1
            node: node1
            options:
              - name: score
                value: 20
          # resource pattern and node name
          - resource:
              pattern: dummy-\d+
            node: node1
            options:
              - name: score
                value: 10
          # resource ID and rule
          - resource:
              id: dummy-2
            rule: '#uname eq node2 and date in_range 2022-01-01 to 2022-02-28'
          # resource pattern and rule
          - resource:
              pattern: dummy-\d+
            rule: node-type eq weekend and date-spec weekdays=6-7
        # colocation constraints
        ha_cluster_constraints_colocation:
          # simple constraint
          - resource_leader:
              id: dummy-3
            resource_follower:
              id: dummy-4
            options:
              - name: score
                value: -5
          # set constraint
          - resource_sets:
              - resource_ids:
                  - dummy-1
                  - dummy-2
              - resource_ids:
                  - dummy-5
                  - dummy-6
                options:
                  - name: sequential
                    value: "false"
            options:
              - name: score
                value: 20
        # order constraints
        ha_cluster_constraints_order:
          # simple constraint
          - resource_first:
              id: dummy-1
            resource_then:
              id: dummy-6
            options:
              - name: symmetrical
                value: "false"
          # set constraint
          - resource_sets:
              - resource_ids:
                  - dummy-1
                  - dummy-2
                options:
                  - name: require-all
                    value: "false"
                  - name: sequential
                    value: "false"
              - resource_ids:
                  - dummy-3
              - resource_ids:
                  - dummy-4
                  - dummy-5
                options:
                  - name: sequential
                    value: "false"
        # ticket constraints
        ha_cluster_constraints_ticket:
          # simple constraint
          - resource:
              id: dummy-1
            ticket: ticket1
            options:
              - name: loss-policy
                value: stop
          # set constraint
          - resource_sets:
              - resource_ids:
                  - dummy-3
                  - dummy-4
                  - dummy-5
            ticket: ticket2
            options:
              - name: loss-policy
                value: fence
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_resource_primitives: <cluster_resources>
    A list of resource definitions for the Pacemaker resources configured by the ha_cluster RHEL system role, including fencing
    ha_cluster_constraints_location: <location_constraints>
    A variable that defines resource location constraints.
    ha_cluster_constraints_colocation: <colocation_constraints>
    A variable that defines resource colocation constraints.
    ha_cluster_constraints_order: <order_constraints>
    A variable that defines resource order constraints.
    ha_cluster_constraints_ticket: <ticket_constraints>
    A variable that defines Booth ticket constraints.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the ha_cluster RHEL system role to configure Corosync values in high availability clusters.

The corosync.conf file provides the cluster parameters used by Corosync, the cluster membership and messaging layer that Pacemaker is built on. For your system configuration, you can change some of the default parameters in the corosync.conf file. In general, you should not edit the corosync.conf file directly. You can, however, configure Corosync values by using the ha_cluster RHEL system role.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create a high availability cluster
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Create cluster that configures Corosync values
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: "{{ cluster_password }}"
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_transport:
          type: knet
          options:
            - name: ip_version
              value: ipv4-6
          links:
            -
              - name: linknumber
                value: 1
              - name: link_priority
                value: 5
            -
              - name: linknumber
                value: 0
              - name: link_priority
                value: 10
          compression:
            - name: level
              value: 5
            - name: model
              value: zlib
          crypto:
            - name: cipher
              value: none
            - name: hash
              value: none
        ha_cluster_totem:
          options:
            - name: block_unlisted_ips
              value: 'yes'
            - name: send_join
              value: 0
        ha_cluster_quorum:
          options:
            - name: auto_tie_breaker
              value: 1
            - name: wait_for_all
              value: 1
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_transport: <transport_method>
    A variable that sets the cluster transport method.
    ha_cluster_totem: <totem_options>
    A variable that configures Corosync totem options.
    ha_cluster_quorum: <quorum_options>
    A variable that configures cluster quorum options.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

As of RHEL 9.6, you can use the ha_cluster RHEL system role to export the Corosync configuration of a cluster into ha_cluster variables that can be fed back to the role to recreate the same cluster.

If you did not use ha_cluster to create your cluster, or if you do not have access to the original playbook for the cluster, you can use this feature to build a new playbook for creating the cluster.

When you export a cluster’s configuration by using the ha_cluster RHEL system role, not all of the variables are exported. You must manually modify the configuration to account for these variables.

The following variables are present in the export:

  • ha_cluster_cluster_present
  • ha_cluster_start_on_boot
  • ha_cluster_cluster_name
  • ha_cluster_transport
  • ha_cluster_totem
  • ha_cluster_quorum
  • ha_cluster_node_options - Only the node_name, corosync_addresses and pcs_address options are present.

The following variables are not present in the export:

  • ha_cluster_hacluster_password - This is a mandatory variable for the role but it cannot be extracted from existing clusters.
  • ha_cluster_corosync_key_src, ha_cluster_pacemaker_key_src and ha_cluster_fence_virt_key_src - These variables should contain paths to files with Corosync and Pacemaker keys. Since the keys themselves are not exported, these variables are not present in the export either. These keys should be unique for each cluster.
  • ha_cluster_regenerate_keys - You should decide whether to use existing keys or to generate new ones.

To export the current cluster configuration, run the ha_cluster RHEL system role and set ha_cluster_export_configuration: true. This triggers the export once the role finishes configuring a cluster or a qnetd host and stores it in the ha_cluster_facts variable.

By default, ha_cluster_cluster_present is set to true and ha_cluster_qnetd.present is set to false. These settings will reconfigure your cluster on the specified hosts, remove qnetd configuration from the specified hosts, and then export the configuration. To trigger the export without modifying an existing configuration, run the role with the following settings: 

- hosts: node1
  vars:
    ha_cluster_cluster_present: null
    ha_cluster_qnetd: null
    ha_cluster_export_configuration: true

  roles:
    - linux-system-roles.ha_cluster
Copy to Clipboard Toggle word wrap

The following procedure:

  • Exports the cluster configuration from cluster node node1 into the ha_cluster_facts variable.
  • Sets the ha_cluster_cluster_present and ha_cluster_qnetd variables to null to ensure that running this playbook does not modify the existing cluster configuration.
  • Uses the Ansible debug module to display the content of ha_cluster_facts.
  • Saves the contents of ha_cluster_facts to a file on the control node in a YAML format for you to write a playbook around it.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Export high availability cluster configuration
  hosts: node1
  Tasks:
    - name: Export configuration that does not modify existing cluster
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
        ha_cluster_cluster_present: null
        ha_cluster_qnetd: null
        ha_cluster_export_configuration: true
    - name: Print ha_cluster_info_result variable
      ansible.builtin.debug:
        var: ha_cluster_facts
    - name: Save current cluster configuration to a file
      delegate_to: localhost
      ansible.builtin.copy:
        content: "{{ ha_cluster_facts | to_nice_yaml(sort_keys=false) }}"
        dest: /path/to/file
        mode: "0640"
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    hosts: node1
    A node containing the cluster information to export.
    ha_cluster_cluster_present: null
    Setting to indicate that the cluster configuration will not be changed on the specified host.
    ha_cluster_qnetd: null
    Setting to indicate that the qnetd host configuration will not be changed on the specified host.
    ha_cluster_export_configuration: true
    A variable that determines whether to export the current cluster configuration and store it in the ha_cluster_facts variable, which is generated by the ha_cluster_info module.
    ha_cluster_facts
    A variable that contains the exported cluster configuration.
    delegate_to: localhost
    Specifies the control node as the location for the exported configuration file.
    content: "{{ ha_cluster_facts | to_nice_yaml(sort_keys=false) }"}, dest: /path/to/file, mode: "0640"
    Copies the configuration file in a YAML format to /path/to/file, setting the file permissions to 0640.

  2. Write a playbook for your system using the variables you exported to /path/to/file on the control node.

    You must add the ha_cluster_hacluster_password variable, as it is a required variable but is not present in the export. Optionally, add the ha_cluster_corosync_key_src, ha_cluster_pacemaker_key_src, ha_cluster_fence_virt_key_src, and ha_cluster_regenerate_keys variables if your system requires them. These variables are never exported.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the ha_cluster RHEL system role to configure high availability clusters with access control lists (ACLs). With ACLs, you can grant permission for specific local users other than user hacluster to manage a Pacemaker cluster.

A common use case for this feature is to restrict unauthorized users from accessing business-sensitive information.

By default, ACLs are not enabled. Consequently, any member of the group haclient on all nodes has full local read and write access to the cluster configuratioan. Users who are not members of haclient have no access. When ACLs are enabled, however, even users who are members of the haclient group have access only to what has been granted to that user by the ACLs. The root and hacluster user accounts always have full access to the cluster configuration, even when ACLs are enabled.

When you set permissions for local users with ACLs, you create a role which defines the permissions for that role. You then assign that role to a user. If you assign multiple roles to the same user, any deny permission takes precedence, then write, then read.

The following example procedure uses the ha_cluster RHEL system role to create in an automated fashion a high availability cluster that implements ACLs to control access to the cluster configuration.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create a high availability cluster
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Configure a cluster with ACLs assigned
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
          ha_cluster_cluster_name: my-new-cluster
          ha_cluster_hacluster_password: "{{ cluster_password }}"
          ha_cluster_manage_firewall: true
          ha_cluster_manage_selinux: true
          # To use an ACL role permission reference, the reference must exist in CIB.
          ha_cluster_resource_primitives:
            - id: not-for-operator
              agent: 'ocf:pacemaker:Dummy'
          # ACLs must be enabled (using the enable-acl cluster property) in order to be effective.
          ha_cluster_cluster_properties:
            - attrs:
                - name: enable-acl
                  value: 'true'
          ha_cluster_acls:
            acl_roles:
              - id: operator
                description: HA cluster operator
                permissions:
                  - kind: write
                    xpath: //crm_config//nvpair[@name='maintenance-mode']
                  - kind: deny
                    reference: not-for-operator
              - id: administrator
                permissions:
                  - kind: write
                    xpath: /cib
            acl_users:
              - id: alice
                roles:
                  - operator
                  - administrator
              - id: bob
                roles:
                  - administrator
            acl_groups:
              - id: admins
                roles:
                  - administrator
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_resource_primitives: <cluster resources>
    A list of resource definitions for the Pacemaker resources configured by the ha_cluster RHEL system role, including fencing resources.
    ha_cluster_cluster_properties: <cluster properties>
    A list of sets of cluster properties for Pacemaker cluster-wide configuration.
    ha_cluster_acls: <dictionary>
    A dictionary of ACL role, user, and group values.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the ha_cluster RHEL system role to configure high availability clusters with STONITH Block Device (SBD) fencing in an automated fashion.

You must configure a Red Hat high availability cluster with at least one fencing device to ensure the cluster-provided services remain available when a node in the cluster encounters a problem. If your environment does not allow for a remotely accessible power switch to fence a cluster node, you can configure fencing by using an SBD. This device provides a node fencing mechanism for Pacemaker-based clusters through the exchange of messages by means of shared block storage. SBD integrates with Pacemaker, a watchdog device and, optionally, shared storage to arrange for nodes to reliably self-terminate when fencing is required.

With ha_cluster, you can configure watchdog and SBD devices on a node-to-node basis by using one of two variables:

  • ha_cluster_node_options: (RHEL 9.5 and later) This is a single variable you define in a playbook file. It is a list of dictionaries where each dictionary defines options for one node.
  • ha_cluster: (RHEL 9.1 and later) A dictionary that defines options for one node only. You configure the ha_cluster variable in an inventory file. To set different values for each node, you define the variable separately for each node.

If both the ha_cluster_node_options and ha_cluster variables contain SBD options, those in ha_cluster_node_options have precedence.

This example procedure uses the ha_cluster_node_options variable in a playbook file to configure node addresses and SBD options on a per-node basis. For an example procedure that uses the ha_cluster variable in an inventory file, see Configuring a high availability cluster with SBD node fencing by using the ha_cluster variable.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create a high availability cluster
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Configure a cluster with SBD fencing
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
        my_sbd_devices:
          # This variable is indirectly used by various variables of the ha_cluster RHEL system role.
          # Its purpose is to define SBD devices once so they do not need
          # to be repeated several times in the role variables.
          - /dev/disk/by-id/000001
          - /dev/disk/by-id/000002
          - /dev/disk/by-id/000003
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: "{{ cluster_password }}"
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_sbd_enabled: true
        ha_cluster_sbd_options:
          - name: delay-start
            value: 'no'
          - name: startmode
            value: always
          - name: timeout-action
            value: 'flush,reboot'
          - name: watchdog-timeout
            value: 30
        ha_cluster_node_options:
          - node_name: node1
            sbd_watchdog_modules:
              - iTCO_wdt
            sbd_watchdog_modules_blocklist:
              - ipmi_watchdog
            sbd_watchdog: /dev/watchdog1
            sbd_devices: "{{ my_sbd_devices }}"
          - node_name: node2
            sbd_watchdog_modules:
              - iTCO_wdt
            sbd_watchdog_modules_blocklist:
              - ipmi_watchdog
            sbd_watchdog: /dev/watchdog1
            sbd_devices: "{{ my_sbd_devices }}"
        # Best practice for setting SBD timeouts:
        # watchdog-timeout * 2 = msgwait-timeout (set automatically)
        # msgwait-timeout * 1.2 = stonith-timeout
        ha_cluster_cluster_properties:
          - attrs:
              - name: stonith-timeout
                value: 72
        ha_cluster_resource_primitives:
          - id: fence_sbd
            agent: 'stonith:fence_sbd'
            instance_attrs:
              - attrs:
                  - name: devices
                    value: "{{ my_sbd_devices | join(',') }}"
                  - name: pcmk_delay_base
                    value: 30
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_sbd_enabled: true
    A variable that determines whether the cluster can use the SBD node fencing mechanism.
    ha_cluster_sbd_options: <sbd options>
    A list of name-value dictionaries specifying SBD options. For information about these options, see the Configuration via environment section of the sbd(8) man page on your system.
    ha_cluster_node_options: <node options>

    A variable that defines settings which vary from one cluster node to another. You can configure the following SBD and watchdog items:

    • sbd_watchdog_modules - Modules to be loaded, which create /dev/watchdog* devices.
    • sbd_watchdog_modules_blocklist - Watchdog kernel modules to be unloaded and blocked.
    • sbd_watchdog - Watchdog device to be used by SBD.
    • sbd_devices - Devices to use for exchanging SBD messages and for monitoring. Always refer to the devices using the long, stable device name (/dev/disk/by-id/).
    ha_cluster_cluster_properties: <cluster properties>
    A list of sets of cluster properties for Pacemaker cluster-wide configuration.
    ha_cluster_resource_primitives: <cluster resources>
    A list of resource definitions for the Pacemaker resources configured by the ha_cluster RHEL system role, including fencing resources.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the ha_cluster RHEL system role to configure high availability clusters with STONITH Block Device (SBD) fencing in an automated fashion.

You must configure a Red Hat high availability cluster with at least one fencing device to ensure the cluster-provided services remain available when a node in the cluster encounters a problem. If your environment does not allow for a remotely accessible power switch to fence a cluster node, you can configure fencing by using an SBD. This device provides a node fencing mechanism for Pacemaker-based clusters through the exchange of messages by means of shared block storage. SBD integrates with Pacemaker, a watchdog device and, optionally, shared storage to arrange for nodes to reliably self-terminate when fencing is required.

With ha_cluster, you can configure watchdog and SBD devices on a node-to-node basis by using one of two variables:

  • ha_cluster_node_options: (RHEL 9.5 and later) This is a single variable you define in a playbook file. It is a list of dictionaries where each dictionary defines options for one node.
  • ha_cluster: (RHEL 9.1 and later) A dictionary that defines options for one node only. You configure the ha_cluster variable in an inventory file. To set different values for each node, you define the variable separately for each node.

If both the ha_cluster_node_options and ha_cluster variables contain SBD options, those in ha_cluster_node_options have precedence.

If both the ha_cluster_node_options and ha_cluster variables contain SBD options, those in ha_cluster_node_options have precedence.`

The following example procedure uses the ha_cluster system role to create a high availability cluster with SBD fencing. This example procedure uses the ha_cluster variable in an inventory file to configure node addresses and SBD options on a per-node basis. For an example procedure that uses the ha_cluster_node_options variable in a playbook file, see Configuring a high availability cluster with SBD node fencing by using the ha_cluster_nodes_options variable.

Warning

The ha_cluster system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The systems that you will use as your cluster members have active subscription coverage for RHEL and the RHEL High Availability Add-On.

Procedure

  1. Create an inventory file for your cluster that configures watchdog and SBD devices for each node by using the ha_cluster variable, as in the following exampla;e 

    all:
  hosts:
    node1:
      ha_cluster:
        sbd_watchdog_modules:
          - iTCO_wdt
        sbd_watchdog_modules_blocklist:
          - ipmi_watchdog
        sbd_watchdog: /dev/watchdog1
        sbd_devices:
          - /dev/disk/by-id/000001
          - /dev/disk/by-id/000001
          - /dev/disk/by-id/000003
    node2:
      ha_cluster:
        sbd_watchdog_modules:
          - iTCO_wdt
        sbd_watchdog_modules_blocklist:
          - ipmi_watchdog
        sbd_watchdog: /dev/watchdog1
        sbd_devices:
          - /dev/disk/by-id/000001
          - /dev/disk/by-id/000002
          - /dev/disk/by-id/000003
    Copy to Clipboard Toggle word wrap

    The SBD and watchdog settings specified in the example inventory include the following:

    sbd_watchdog_modules
    Watchdog kernel modules to be loaded, which create /dev/watchdog* devices.
    sbd_watchdog_modules_blocklist
    Watchdog kernel modules to be unloaded and blocked.
    sbd_watchdog
    Watchdog device to be used by SBD.
    sbd_devices
    Devices to use for exchanging SBD messages and for monitoring. Always refer to the devices using the long, stable device name (/dev/disk/by-id/).

    For general information about creating an inventory file, see Preparing a control node on RHEL 9.

  2. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  3. Create a playbook file, for example, ~/playbook.yml, as in the following example. Since you have specified the SBD and watchog variables in an inventory, you do not need to include them in the playbook. 

    ---
- name: Create a high availability cluster
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Configure a cluster with sbd fencing devices configured in an inventory file
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
          ha_cluster_cluster_name: my-new-cluster
          ha_cluster_hacluster_password: "{{ cluster_password }}"
          ha_cluster_manage_firewall: true
          ha_cluster_manage_selinux: true
          ha_cluster_sbd_enabled: true
          ha_cluster_sbd_options:
            - name: delay-start
              value: 'no'
            - name: startmode
              value: always
            - name: timeout-action
              value: 'flush,reboot'
            - name: watchdog-timeout
              value: 30
          # Best practice for setting SBD timeouts:
          # watchdog-timeout * 2 = msgwait-timeout (set automatically)
          # msgwait-timeout * 1.2 = stonith-timeout
          ha_cluster_cluster_properties:
            - attrs:
                - name: stonith-timeout
                  value: 72
          ha_cluster_resource_primitives:
            - id: fence_sbd
              agent: 'stonith:fence_sbd'
              instance_attrs:
                - attrs:
                    # taken from host_vars
                    # this only works if all nodes have the same sbd_devices
                    - name: devices
                      value: "{{ ha_cluster.sbd_devices | join(',') }}"
                    - name: pcmk_delay_base
                      value: 30
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: cluster_name
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: password
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_sbd_enabled: true
    A variable that determines whether the cluster can use the SBD node fencing mechanism.
    ha_cluster_sbd_options: sbd options
    A list of name-value dictionaries specifying SBD options. For information about these options, see the Configuration via environment section of the sbd(8) man page on your system.
    ha_cluster_cluster_properties: cluster properties
    A list of sets of cluster properties for Pacemaker cluster-wide configuration.
    ha_cluster_resource_primitives: cluster resources
    A list of resource definitions for the Pacemaker resources configured by the ha_cluster RHEL system role, including fencing resources.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

  4. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  5. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the ha_cluster RHEL system role to create a high availability cluster in an automated fashion that configures utilization attributes to define a placement strategy.

A Pacemaker cluster allocates resources according to a resource allocation score. By default, if the resource allocation scores on all the nodes are equal, Pacemaker allocates the resource to the node with the smallest number of allocated resources. If the resources in your cluster use significantly different proportions of a node’s capacities, such as memory or I/O, the default behavior may not be the best strategy for balancing your system’s workload. In this case, you can customize an allocation strategy by configuring utilization attributes and placement strategies for nodes and resources.

For detailed information about configuring utilization attributes and placement strategies, see Configuring a node placement strategy.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create a high availability cluster
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Configure a cluster with utilization attributes
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
          ha_cluster_cluster_name: my-new-cluster
          ha_cluster_hacluster_password: "{{ cluster_password }}"
          ha_cluster_manage_firewall: true
          ha_cluster_manage_selinux: true
          ha_cluster_cluster_properties:
            - attrs:
                - name: placement-strategy
                  value: utilization
          ha_cluster_node_options:
            - node_name: node1
              utilization:
                - attrs:
                    - name: utilization1
                      value: 1
                    - name: utilization2
                      value: 2
            - node_name: node2
              utilization:
                - attrs:
                    - name: utilization1
                      value: 3
                    - name: utilization2
                      value: 4
          ha_cluster_resource_primitives:
            - id: resource1
              agent: 'ocf:pacemaker:Dummy'
              utilization:
                - attrs:
                    - name: utilization1
                      value: 2
                    - name: utilization2
                      value: 3
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_cluster_properties: <cluster properties>
    List of sets of cluster properties for Pacemaker cluster-wide configuration. For utilization to have an effect, the placement-strategy property must be set and its value must be different from the value default.
    `ha_cluster_node_options: <node options>
    A variable that defines various settings which vary from cluster node to cluster node.
    ha_cluster_resource_primitives: <cluster resources>

    A list of resource definitions for the Pacemaker resources configured by the ha_cluster RHEL system role, including fencing resources.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the ha_cluster RHEL system role to configure alerts for high availability clusters.

When a Pacemaker event occurs, such as a resource or a node failure or a configuration change, you may want to take some external action. For example, you may want to send an email message or log to a file or update a monitoring system.

You can configure your system to take an external action by using alert agents. These are external programs that the cluster calls in the same manner as the cluster calls resource agents to handle resource configuration and operation. The cluster passes information about the event to the agent through environment variables.

Note

The ha_cluster RHEL system role configures the cluster to call external programs to handle alerts. However, you must provide these programs and distribute them to cluster nodes.

For more detailed information about alert agents, see Triggering scripts for cluster events.

This example procedure uses the ha_cluster RHEL system role to create a high availability cluster in an automated fashion that configures a Pacemaker alert.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create a high availability cluster
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Configure a cluster with alerts
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
          ha_cluster_cluster_name: my-new-cluster
          ha_cluster_hacluster_password: "{{ cluster_password }}"
          ha_cluster_manage_firewall: true
          ha_cluster_manage_selinux: true
          ha_cluster_alerts:
            - id: alert1
              path: /alert1/path
              description: Alert1 description
              instance_attrs:
                - attrs:
                    - name: alert_attr1_name
                      value: alert_attr1_value
              meta_attrs:
                - attrs:
                    - name: alert_meta_attr1_name
                      value: alert_meta_attr1_value
              recipients:
                - value: recipient_value
                  id: recipient1
                  description: Recipient1 description
                  instance_attrs:
                    - attrs:
                        - name: recipient_attr1_name
                          value: recipient_attr1_value
                  meta_attrs:
                    - attrs:
                        - name: recipient_meta_attr1_name
                          value: recipient_meta_attr1_value
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_alerts: <alert definitions>

    A variable that defines Pacemaker alerts.

    • id - ID of an alert.
    • path - Path to the alert agent executable.
    • description- Description of the alert.
    • instance_attrs - List of sets of the alert’s instance attributes. Currently, only one set is supported, so the first set is used and the rest are ignored.
    • meta_attrs - List of sets of the alert’s meta attributes. Currently, only one set is supported, so the first set is used and the rest are ignored.
    • recipients - List of alert’s recipients.
    • value- Value of a recipient.
    • id - ID of the recipient.
    • description - Description of the recipient.
    • instance_attrs -List of sets of the recipient’s instance attributes. Currently, only one set is supported, so the first set is used and the rest are ignored.
    • meta_attrs - List of sets of the recipient’s meta attributes. Currently, only one set is supported, so the first set is used and the rest are ignored.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Your cluster can sustain more node failures than standard quorum rules permit when you configure a separate quorum device. The quorum device acts as a lightweight arbitration device for the cluster. Use a quorum device for clusters with an even number of nodes.

With two-node clusters, the use of a quorum device can better determine which node survives in a split-brain situation.

For information about quorum devices, see Configuring quorum devices.

To configure a high availability cluster with a separate quorum device by using the ha_cluster RHEL system role, first set up the quorum device. After setting up the quorum device, you can use the device in any number of clusters.

This feature is available in RHEL 9.2 and later.

11.16.1. Configuring a quorum device
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You can use the ha_cluster RHEL system role to configure a quorum device for high availability clusters. Note that you cannot run a quorum device on a cluster node.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook-qdevice.yml, with the following content: 

    ---
- name: Configure a host with a quorum device
  hosts: nodeQ
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Create a quorum device for the cluster
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
        ha_cluster_cluster_present: false
        ha_cluster_hacluster_password: "{{ cluster_password }}"
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_qnetd:
          present: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ha_cluster_cluster_present: false
    A variable that, if set to false, determines that all cluster configuration will be removed from the target host.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_qnetd: <quorum_device_options>
    A variable that configures a qnetd host.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook-qdevice.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook-qdevice.yml
    Copy to Clipboard Toggle word wrap

You can use the ha_cluster RHEL system role to configure a cluster with a quorum device.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook-cluster-qdevice.yml, with the following content: 

    ---
- name: Configure a cluster to use a quorum device
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Create cluster that uses a quorum device
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: "{{ cluster_password }}"
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_quorum:
          device:
            model: net
            model_options:
              - name: host
                value: nodeQ
              - name: algorithm
                value: lms
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_quorum: <quorum_parameters>
    A variable that configures cluster quorum which you can use to specify that the cluster uses a quorum device.

  2. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook-cluster-qdevice.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook-cluster-qdevice.yml
    Copy to Clipboard Toggle word wrap

You can use Pacemaker rules to make your configuration more dynamic. For example, you can use a node attribute to assign machines to different processing groups based on time and then use that attribute when creating location constraints.

Node attribute expressions are used to control a resource based on the attributes defined by a node or nodes. For information on node attributes, see Determining resource location with rules.

The following example procedure uses the ha_cluster RHEL system role to create a high availability cluster that configures node attributes.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create a high availability cluster
  hosts: node1 node2
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Create a cluster that defines node attributes
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
        ha_cluster_cluster_name: my-new-cluster
        ha_cluster_hacluster_password: "{{ cluster_password }}"
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_node_options:
          - node_name: node1
            attributes:
              - attrs:
                  - name: attribute1
                    value: value1A
                  - name: attribute2
                    value: value2A
          - node_name: node2
            attributes:
              - attrs:
                  - name: attribute1
                    value: value1B
                  - name: attribute2
                    value: value2B
    Copy to Clipboard Toggle word wrap
    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_node_options: <node_settings>
    A variable that defines various settings that vary from one cluster node to another.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Additional resources

You can use the ha_cluster RHEL system role to configure an Apache HTTP server in a high availability cluster.

High availability clusters provide highly available services by eliminating single points of failure and by failing over services from one cluster node to another in case a node becomes inoperative. Red Hat provides a variety of documentation for planning, configuring, and maintaining a Red Hat high availability cluster. For a listing of articles that provide indexes to the various areas of Red Hat cluster documentation, see the Red Hat High Availability Add-On Documentation Guide.

The following example use case configures an active/passive Apache HTTP server in a two-node Red Hat Enterprise Linux High Availability Add-On cluster by using the ha_cluster RHEL system role. In this use case, clients access the Apache HTTP server through a floating IP address. The web server runs on one of two nodes in the cluster. If the node on which the web server is running becomes inoperative, the web server starts up again on the second node of the cluster with minimal service interruption.

This example uses an APC power switch with a host name of zapc.example.com. If the cluster does not use any other fence agents, you can optionally list only the fence agents your cluster requires when defining the ha_cluster_fence_agent_packages variable, as in this example.

Warning

The ha_cluster RHEL system role replaces any existing cluster configuration on the specified nodes. Any settings not specified in the playbook will be lost.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      cluster_password: <cluster_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Create a high availability cluster
  hosts: z1.example.com z2.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Configure active/passive Apache server in a high availability cluster
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ha_cluster
      vars:
        ha_cluster_hacluster_password: "{{ cluster_password }}"
        ha_cluster_cluster_name: my_cluster
        ha_cluster_manage_firewall: true
        ha_cluster_manage_selinux: true
        ha_cluster_fence_agent_packages:
          - fence-agents-apc-snmp
        ha_cluster_resource_primitives:
          - id: myapc
            agent: stonith:fence_apc_snmp
            instance_attrs:
              - attrs:
                  - name: ipaddr
                    value: zapc.example.com
                  - name: pcmk_host_map
                    value: z1.example.com:1;z2.example.com:2
                  - name: login
                    value: apc
                  - name: passwd
                    value: apc
          - id: my_lvm
            agent: ocf:heartbeat:LVM-activate
            instance_attrs:
              - attrs:
                  - name: vgname
                    value: my_vg
                  - name: vg_access_mode
                    value: system_id
          - id: my_fs
            agent: Filesystem
            instance_attrs:
              - attrs:
                  - name: device
                    value: /dev/my_vg/my_lv
                  - name: directory
                    value: /var/www
                  - name: fstype
                    value: xfs
          - id: VirtualIP
            agent: IPaddr2
            instance_attrs:
              - attrs:
                  - name: ip
                    value: 198.51.100.3
                  - name: cidr_netmask
                    value: 24
          - id: Website
            agent: apache
            instance_attrs:
              - attrs:
                  - name: configfile
                    value: /etc/httpd/conf/httpd.conf
                  - name: statusurl
                    value: http://127.0.0.1/server-status
        ha_cluster_resource_groups:
          - id: apachegroup
            resource_ids:
              - my_lvm
              - my_fs
              - VirtualIP
              - Website
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ha_cluster_cluster_name: <cluster_name>
    The name of the cluster you are creating.
    ha_cluster_hacluster_password: <password>
    The password of the hacluster user. The hacluster user has full access to a cluster.
    ha_cluster_manage_firewall: true
    A variable that determines whether the ha_cluster RHEL system role manages the firewall.
    ha_cluster_manage_selinux: true
    A variable that determines whether the ha_cluster RHEL system role manages the ports of the firewall high availability service using the selinux RHEL system role.
    ha_cluster_fence_agent_packages: <fence_agent_packages>
    A list of fence agent packages to install.
    ha_cluster_resource_primitives: <cluster_resources>
    A list of resource definitions for the Pacemaker resources configured by the ha_cluster RHEL system role, including fencing
    ha_cluster_resource_groups: <resource_groups>
    A list of resource group definitions configured by the ha_cluster RHEL system role.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ha_cluster/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

  5. When you use the apache resource agent to manage Apache, it does not use systemd. Because of this, you must edit the logrotate script supplied with Apache so that it does not use systemctl to reload Apache.

    Remove the following line in the /etc/logrotate.d/httpd file on each node in the cluster. 

    # /bin/systemctl reload httpd.service > /dev/null 2>/dev/null || true
    Copy to Clipboard Toggle word wrap

    Replace the line you removed with the following three lines, specifying /var/run/httpd-website.pid as the PID file path where website is the name of the Apache resource. In this example, the Apache resource name is Website. 

    /usr/bin/test -f /var/run/httpd-Website.pid >/dev/null 2>/dev/null &&
/usr/bin/ps -q $(/usr/bin/cat /var/run/httpd-Website.pid) >/dev/null 2>/dev/null &&
/usr/sbin/httpd -f /etc/httpd/conf/httpd.conf -c "PidFile /var/run/httpd-Website.pid" -k graceful > /dev/null 2>/dev/null || true
    Copy to Clipboard Toggle word wrap

Verification

  1. From one of the nodes in the cluster, check the status of the cluster. Note that all four resources are running on the same node, z1.example.com.

    If you find that the resources you configured are not running, you can run the pcs resource debug-start resource command to test the resource configuration. 

    [root@z1 ~]# pcs status
Cluster name: my_cluster
Last updated: Wed Jul 31 16:38:51 2013
Last change: Wed Jul 31 16:42:14 2013 via crm_attribute on z1.example.com
Stack: corosync
Current DC: z2.example.com (2) - partition with quorum
Version: 1.1.10-5.el7-9abe687
2 Nodes configured
6 Resources configured

Online: [ z1.example.com z2.example.com ]

Full list of resources:
 myapc  (stonith:fence_apc_snmp):       Started z1.example.com
 Resource Group: apachegroup
     my_lvm     (ocf::heartbeat:LVM-activate):   Started z1.example.com
     my_fs      (ocf::heartbeat:Filesystem):    Started z1.example.com
     VirtualIP  (ocf::heartbeat:IPaddr2):       Started z1.example.com
     Website    (ocf::heartbeat:apache):        Started z1.example.com
    Copy to Clipboard Toggle word wrap

  2. Once the cluster is up and running, you can point a browser to the IP address you defined as the IPaddr2 resource to view the sample display, consisting of the simple word "Hello". 

    Hello
    Copy to Clipboard Toggle word wrap

  3. To test whether the resource group running on z1.example.com fails over to node z2.example.com, put node z1.example.com in standby mode, after which the node will no longer be able to host resources. 

    [root@z1 ~]# pcs node standby z1.example.com
    Copy to Clipboard Toggle word wrap

  4. After putting node z1 in standby mode, check the cluster status from one of the nodes in the cluster. Note that the resources should now all be running on z2. 

    [root@z1 ~]# pcs status
Cluster name: my_cluster
Last updated: Wed Jul 31 17:16:17 2013
Last change: Wed Jul 31 17:18:34 2013 via crm_attribute on z1.example.com
Stack: corosync
Current DC: z2.example.com (2) - partition with quorum
Version: 1.1.10-5.el7-9abe687
2 Nodes configured
6 Resources configured

Node z1.example.com (1): standby
Online: [ z2.example.com ]

Full list of resources:

 myapc  (stonith:fence_apc_snmp):       Started z1.example.com
 Resource Group: apachegroup
     my_lvm     (ocf::heartbeat:LVM-activate):  Started z2.example.com
     my_fs      (ocf::heartbeat:Filesystem):    Started z2.example.com
     VirtualIP  (ocf::heartbeat:IPaddr2):       Started z2.example.com
     Website    (ocf::heartbeat:apache):        Started z2.example.com
    Copy to Clipboard Toggle word wrap

    The website at the defined IP address should still display, without interruption.

  5. To remove z1 from standby mode, enter the following command. 

    [root@z1 ~]# pcs node unstandby z1.example.com
    Copy to Clipboard Toggle word wrap
    Note

    Removing a node from standby mode does not in itself cause the resources to fail back over to that node. This will depend on the resource-stickiness value for the resources. For information about the resource-stickiness meta attribute, see Configuring a resource to prefer its current node.

With the journald RHEL system role you can automate the systemd journal, and configure persistent logging by using the Red Hat Ansible Automation Platform.

By default, the systemd journal stores logs only in a small ring buffer in /run/log/journal, which is not persistent. Rebooting the system also removes journal database logs. You can configure persistent logging consistently on multiple systems by using the journald RHEL system role.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure journald
  hosts: managed-node-01.example.com
  tasks:
    - name: Configure persistent logging
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.journald
      vars:
        journald_persistent: true
        journald_max_disk_size: <size>
        journald_per_user: true
        journald_sync_interval: <interval>
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    journald_persistent: true
    Enables persistent logging.
    journald_max_disk_size: <size>
    Specifies the maximum size of disk space for journal files in MB, for example, 2048.
    journald_per_user: true
    Configures journald to keep log data separate for each user.
    journald_sync_interval: <interval>

    Sets the synchronization interval in minutes, for example, 1.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.journald/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

To manage kdump using Ansible, you can use the kdump role, which is one of the RHEL system roles available in RHEL 9.

Using the kdump role enables you to specify where to save the contents of the system’s memory for later analysis.

Kernel crash dumping is a crucial feature for diagnosing and troubleshooting system issues. When your system encounters a kernel panic or other critical failure, crash kernel dumping allows you to capture a memory dump (core dump) of the kernel’s state at the time of the failure.

By using an Ansible playbook, you can set kernel crash dump parameters on multiple systems using the kdump RHEL system role. This ensures consistent settings across all managed nodes for the kdump service.

Warning

The kdump system role replaces the content in the /etc/kdump.conf and /etc/sysconfig/kdump configuration files. Previous settings are changed to those specified in the role variables, and lost if they are not specified in the role variables.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configuring kernel crash dumping
  hosts: managed-node-01.example.com
  tasks:
    - name: Setting the kdump directory.
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.kdump
      vars:
        kdump_target:
          type: raw
          location: /dev/sda1
        kdump_path: /var/crash/vmcore
        kernel_settings_reboot_ok: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    kdump_target: <type_and_location>
    Writes vmcore to a location other than the root file system. The location refers to a partition (by name, label, or UUID) when the type is raw or file system.
    kernel_settings_reboot_ok: <true|false>
    The default is false. If set to true, the system role will determine if a reboot of the managed host is necessary for the requested changes to take effect and reboot it. If set to false, the role will return the variable kernel_settings_reboot_required with a value of true, indicating that a reboot is required. In this case, a user must reboot the managed node manually.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.kdump/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Verify the kernel crash dump parameters: 

    $ ansible managed-node-01.example.com -m command -a 'grep crashkernel /proc/cmdline'
    Copy to Clipboard Toggle word wrap

You can use the kernel_settings RHEL system role to configure kernel parameters on multiple clients simultaneously.

Simultaneous configuration has the following advantages:

  • Provides a friendly interface with efficient input setting.
  • Keeps all intended kernel parameters in one place.

After you run the kernel_settings role from the control machine, the kernel parameters are applied to the managed systems immediately and persist across reboots.

Important

Note that RHEL system role delivered over RHEL channels are available to RHEL customers as an RPM package in the default AppStream repository. RHEL system role are also available as a collection to customers with Ansible subscriptions over Ansible Automation Hub.

You can use the kernel_settings RHEL system role to remotely configure various kernel parameters across multiple managed operating systems with persistent effects.

For example, by using the kernel_settings role, you can configure:

  • Transparent hugepages to increase performance by reducing the overhead of managing smaller pages.
  • The largest packet sizes to be transmitted over the network with the loopback interface.
  • Limits on files to be opened simultaneously.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configuring kernel settings
  hosts: managed-node-01.example.com
  tasks:
    - name: Configure hugepages, packet size for loopback device, and limits on simultaneously open files.
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.kernel_settings
      vars:
        kernel_settings_sysctl:
          - name: fs.file-max
            value: 400000
          - name: kernel.threads-max
            value: 65536
        kernel_settings_sysfs:
          - name: /sys/class/net/lo/mtu
            value: 65000
        kernel_settings_transparent_hugepages: madvise
        kernel_settings_reboot_ok: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    kernel_settings_sysfs: <list_of_sysctl_settings>
    A YAML list of sysctl settings and the values you want to assign to these settings.
    kernel_settings_transparent_hugepages: <value>
    Controls the memory subsystem Transparent Huge Pages (THP) setting. You can disable THP support (never), enable it system wide (always) or inside MAD_HUGEPAGE regions (madvise).
    kernel_settings_reboot_ok: <true|false>
    The default is false. If set to true, the system role will determine if a reboot of the managed host is necessary for the requested changes to take effect and reboot it. If set to false, the role will return the variable kernel_settings_reboot_required with a value of true, indicating that a reboot is required. In this case, a user must reboot the managed node manually.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.kdump/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Verify the affected kernel parameters: 

    # ansible managed-node-01.example.com -m command -a 'sysctl fs.file-max kernel.threads-max net.ipv6.conf.lo.mtu'
# ansible managed-node-01.example.com -m command -a 'cat /sys/kernel/mm/transparent_hugepage/enabled'
    Copy to Clipboard Toggle word wrap

You can use the logging RHEL system role to configure your local and remote hosts as logging servers in an automated fashion to collect logs from many client systems.

Logging solutions provide multiple ways of reading logs and multiple logging outputs.

For example, a logging system can receive the following inputs:

  • Local files
  • systemd/journal
  • Another logging system over the network

In addition, a logging system can have the following outputs:

  • Logs stored in the local files in the /var/log/ directory
  • Logs sent to Elasticsearch engine
  • Logs forwarded to another logging system

With the logging RHEL system role, you can combine the inputs and outputs to fit your scenario. For example, you can configure a logging solution that stores inputs from journal in a local file, whereas inputs read from files are both forwarded to another logging system and stored in the local log files.

You can use the property-based filter of the logging RHEL system role to filter your local log messages based on various conditions.

You can achieve, for example:

  • Log clarity: In a high-traffic environment, logs can grow rapidly. The focus on specific messages, like errors, can help to identify problems faster.
  • Optimized system performance: Excessive amount of logs is usually connected with system performance degradation. Selective logging for only the important events can prevent resource depletion, which enables your systems to run more efficiently.
  • Enhanced security: Efficient filtering through security messages, like system errors and failed logins, helps to capture only the relevant logs. This is important for detecting breaches and meeting compliance standards.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Deploy the logging solution
  hosts: managed-node-01.example.com
  tasks:
    - name: Filter logs based on a specific value they contain
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.logging
      vars:
        logging_inputs:
          - name: files_input
            type: basics
        logging_outputs:
          - name: files_output0
            type: files
            property: msg
            property_op: contains
            property_value: error
            path: /var/log/errors.log
          - name: files_output1
            type: files
            property: msg
            property_op: "!contains"
            property_value: error
            path: /var/log/others.log
        logging_flows:
          - name: flow0
            inputs: [files_input]
            outputs: [files_output0, files_output1]
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    logging_inputs
    Defines a list of logging input dictionaries. The type: basics option covers inputs from systemd journal or Unix socket.
    logging_outputs
    Defines a list of logging output dictionaries. The type: files option supports storing logs in the local files, usually in the /var/log/ directory. The property: msg; property: contains; and property_value: error options specify that all logs that contain the error string are stored in the /var/log/errors.log file. The property: msg; property: !contains; and property_value: error options specify that all other logs are put in the /var/log/others.log file. You can replace the error value with the string by which you want to filter.
    logging_flows
    Defines a list of logging flow dictionaries to specify relationships between logging_inputs and logging_outputs. The inputs: [files_input] option specifies a list of inputs, from which processing of logs starts. The outputs: [files_output0, files_output1] option specifies a list of outputs, to which the logs are sent.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.logging/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. On the managed node, test the syntax of the /etc/rsyslog.conf file: 

    # rsyslogd -N 1
rsyslogd: version 8.1911.0-6.el8, config validation run...
rsyslogd: End of config validation run. Bye.
    Copy to Clipboard Toggle word wrap

  2. On the managed node, verify that the system sends messages that contain the error string to the log:

    1. Send a test message: 

      # logger error
      Copy to Clipboard Toggle word wrap

    2. View the /var/log/errors.log log, for example: 

      # cat /var/log/errors.log
Aug  5 13:48:31 hostname root[6778]: error
      Copy to Clipboard Toggle word wrap

      Where hostname is the host name of the client system. Note that the log contains the user name of the user that entered the logger command, in this case root.

You can use the logging RHEL system role to configure centralized log management across multiple systems. The server receives remote input from the remote_rsyslog and remote_files configurations, and outputs the logs to local files in directories named by remote host names.

As a result, you can cover use cases where you need for example:

  • Centralized log management: Collecting, accessing, and managing log messages of multiple machines from a single storage point simplifies day-to-day monitoring and troubleshooting tasks. Also, this use case reduces the need to log in to individual machines to check the log messages.
  • Enhanced security: Storing log messages in one central place increases chances they are in a secure and tamper-proof environment. Such an environment makes it easier to detect and respond to security incidents more effectively and to meet audit requirements.
  • Improved efficiency in log analysis: Correlating log messages from multiple systems is important for fast troubleshooting of complex problems that span multiple machines or services. That way you can quickly analyze and cross-reference events from different sources.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Deploy the logging solution
  hosts: managed-node-01.example.com
  tasks:
    - name: Configure the server to receive remote input
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.logging
      vars:
        logging_inputs:
          - name: remote_udp_input
            type: remote
            udp_ports: [ 601 ]
          - name: remote_tcp_input
            type: remote
            tcp_ports: [ 601 ]
        logging_outputs:
          - name: remote_files_output
            type: remote_files
        logging_flows:
          - name: flow_0
            inputs: [remote_udp_input, remote_tcp_input]
            outputs: [remote_files_output]

- name: Deploy the logging solution
  hosts: managed-node-02.example.com
  tasks:
    - name: Configure the server to output the logs to local files in directories named by remote host names
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.logging
      vars:
        logging_inputs:
          - name: basic_input
            type: basics
        logging_outputs:
          - name: forward_output0
            type: forwards
            severity: info
            target: <host1.example.com>
            udp_port: 601
          - name: forward_output1
            type: forwards
            facility: mail
            target: <host1.example.com>
            tcp_port: 601
        logging_flows:
          - name: flows0
            inputs: [basic_input]
            outputs: [forward_output0, forward_output1]
    Copy to Clipboard Toggle word wrap

    The settings specified in the first play of the example playbook include the following:

    logging_inputs
    Defines a list of logging input dictionaries. The type: remote option covers remote inputs from the other logging system over the network. The udp_ports: [ 601 ] option defines a list of UDP port numbers to monitor. The tcp_ports: [ 601 ] option defines a list of TCP port numbers to monitor. If both udp_ports and tcp_ports is set, udp_ports is used and tcp_ports is dropped.
    logging_outputs
    Defines a list of logging output dictionaries. The type: remote_files option makes output store logs to the local files per remote host and program name originated the logs.
    logging_flows
    Defines a list of logging flow dictionaries to specify relationships between logging_inputs and logging_outputs. The inputs: [remote_udp_input, remote_tcp_input] option specifies a list of inputs, from which processing of logs starts. The outputs: [remote_files_output] option specifies a list of outputs, to which the logs are sent.

    The settings specified in the second play of the example playbook include the following:

    logging_inputs
    Defines a list of logging input dictionaries. The type: basics option covers inputs from systemd journal or Unix socket.
    logging_outputs
    Defines a list of logging output dictionaries. The type: forwards option supports sending logs to the remote logging server over the network. The severity: info option refers to log messages of the informative importance. The facility: mail option refers to the type of system program that is generating the log message. The target: <host1.example.com> option specifies the hostname of the remote logging server. The udp_port: 601/tcp_port: 601 options define the UDP/TCP ports on which the remote logging server listens.
    logging_flows
    Defines a list of logging flow dictionaries to specify relationships between logging_inputs and logging_outputs. The inputs: [basic_input] option specifies a list of inputs, from which processing of logs starts. The outputs: [forward_output0, forward_output1] option specifies a list of outputs, to which the logs are sent.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.logging/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. On both the client and the server system, test the syntax of the /etc/rsyslog.conf file: 

    # rsyslogd -N 1
rsyslogd: version 8.1911.0-6.el8, config validation run (level 1), master config /etc/rsyslog.conf
rsyslogd: End of config validation run. Bye.
    Copy to Clipboard Toggle word wrap

  2. Verify that the client system sends messages to the server:

    1. On the client system, send a test message: 

      # logger test
      Copy to Clipboard Toggle word wrap

    2. On the server system, view the /var/log/<host2.example.com>/messages log, for example: 

      # cat /var/log/<host2.example.com>/messages
Aug  5 13:48:31 <host2.example.com> root[6778]: test
      Copy to Clipboard Toggle word wrap

      Where <host2.example.com> is the host name of the client system. Note that the log contains the user name of the user that entered the logger command, in this case root.

15.3. Using the logging RHEL system role with TLS
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You can use the logging RHEL system role to configure a secure transfer of log messages, where one or more clients take logs from the systemd-journal service and transfer them to a remote server while using TLS.

Typically, TLS for transferring logs in a remote logging solution is used when sending sensitive data over less trusted or public networks, such as the Internet. Also, by using certificates in TLS you can ensure that the client is forwarding logs to the correct and trusted server. This prevents attacks like "man-in-the-middle".

15.3.1. Configuring client logging with TLS
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You can use the logging RHEL system role to configure logging on RHEL clients and transfer logs to a remote logging system using TLS encryption.

The role creates a private key and a certificate. Next, it configures TLS on all hosts in the clients group in the Ansible inventory. The TLS protocol encrypts the message transmission for secure transfer of logs over the network.

Note

You do not have to call the certificate RHEL system role in the playbook to create the certificate. The logging RHEL system role calls it automatically when the logging_certificates variable is set.

In order for the CA to be able to sign the created certificate, the managed nodes must be enrolled in an IdM domain.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes are enrolled in an IdM domain.
  • If the logging server you want to configure on the manage node runs RHEL 9.2 or later and the FIPS mode is enabled, clients must either support the Extended Master Secret (EMS) extension or use TLS 1.3. TLS 1.2 connections without EMS fail. For more information, see the Red Hat Knowledgebase solution TLS extension "Extended Master Secret" enforced.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure remote logging solution using TLS for secure transfer of logs
  hosts: managed-node-01.example.com
  tasks:
    - name: Deploying files input and forwards output with certs
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.logging
      vars:
        logging_certificates:
          - name: logging_cert
            dns: ['www.example.com']
            ca: ipa
            principal: "logging/{{ inventory_hostname }}@IDM.EXAMPLE.COM"
        logging_pki_files:
          - ca_cert: /local/path/to/ca_cert.pem
            cert: /local/path/to/logging_cert.pem
            private_key: /local/path/to/logging_cert.pem
        logging_inputs:
          - name: input_name
            type: files
            input_log_path: /var/log/containers/*.log
        logging_outputs:
          - name: output_name
            type: forwards
            target: your_target_host
            tcp_port: 514
            tls: true
            pki_authmode: x509/name
            permitted_server: 'server.example.com'
        logging_flows:
          - name: flow_name
            inputs: [input_name]
            outputs: [output_name]
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    logging_certificates
    The value of this parameter is passed on to certificate_requests in the certificate RHEL system role and used to create a private key and certificate.
    logging_pki_files

    Using this parameter, you can configure the paths and other settings that logging uses to find the CA, certificate, and key files used for TLS, specified with one or more of the following sub-parameters: ca_cert, ca_cert_src, cert, cert_src, private_key, private_key_src, and tls.

    Note

    If you are using logging_certificates to create the files on the managed node, do not use ca_cert_src, cert_src, and private_key_src, which are used to copy files not created by logging_certificates.

    ca_cert
    Represents the path to the CA certificate file on the managed node. Default path is /etc/pki/tls/certs/ca.pem and the file name is set by the user.
    cert
    Represents the path to the certificate file on the managed node. Default path is /etc/pki/tls/certs/server-cert.pem and the file name is set by the user.
    private_key
    Represents the path to the private key file on the managed node. Default path is /etc/pki/tls/private/server-key.pem and the file name is set by the user.
    ca_cert_src
    Represents the path to the CA certificate file on the control node which is copied to the target host to the location specified by ca_cert. Do not use this if using logging_certificates.
    cert_src
    Represents the path to a certificate file on the control node which is copied to the target host to the location specified by cert. Do not use this if using logging_certificates.
    private_key_src
    Represents the path to a private key file on the control node which is copied to the target host to the location specified by private_key. Do not use this if using logging_certificates.
    tls
    Setting this parameter to true ensures secure transfer of logs over the network. If you do not want a secure wrapper, you can set tls: false.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.logging/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Additional resources

15.3.2. Configuring server logging with TLS
Copy link

You can use the logging RHEL system role to configure logging on RHEL servers and set them to receive logs from a remote logging system using TLS encryption.

The role creates a private key and a certificate. Next, it configures TLS on all hosts in the server group in the Ansible inventory.

Note

You do not have to call the certificate RHEL system role in the playbook to create the certificate. The logging RHEL system role calls it automatically.

In order for the CA to be able to sign the created certificate, the managed nodes must be enrolled in an IdM domain.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes are enrolled in an IdM domain.
  • If the logging server you want to configure on the manage node runs RHEL 9.2 or later and the FIPS mode is enabled, clients must either support the Extended Master Secret (EMS) extension or use TLS 1.3. TLS 1.2 connections without EMS fail. For more information, see the Red Hat Knowledgebase solution TLS extension "Extended Master Secret" enforced.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure remote logging solution using TLS for secure transfer of logs
  hosts: managed-node-01.example.com
  tasks:
    - name: Deploying remote input and remote_files output with certs
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.logging
      vars:
        logging_certificates:
          - name: logging_cert
            dns: ['www.example.com']
            ca: ipa
            principal: "logging/{{ inventory_hostname }}@IDM.EXAMPLE.COM"
        logging_pki_files:
          - ca_cert: /local/path/to/ca_cert.pem
            cert: /local/path/to/logging_cert.pem
            private_key: /local/path/to/logging_cert.pem
        logging_inputs:
          - name: input_name
            type: remote
            tcp_ports: [514]
            tls: true
            permitted_clients: ['clients.example.com']
        logging_outputs:
          - name: output_name
            type: remote_files
            remote_log_path: /var/log/remote/%FROMHOST%/%PROGRAMNAME:::secpath-replace%.log
            async_writing: true
            client_count: 20
            io_buffer_size: 8192
        logging_flows:
          - name: flow_name
            inputs: [input_name]
            outputs: [output_name]
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    logging_certificates
    The value of this parameter is passed on to certificate_requests in the certificate RHEL system role and used to create a private key and certificate.
    logging_pki_files

    Using this parameter, you can configure the paths and other settings that logging uses to find the CA, certificate, and key files used for TLS, specified with one or more of the following sub-parameters: ca_cert, ca_cert_src, cert, cert_src, private_key, private_key_src, and tls.

    Note

    If you are using logging_certificates to create the files on the managed node, do not use ca_cert_src, cert_src, and private_key_src, which are used to copy files not created by logging_certificates.

    ca_cert
    Represents the path to the CA certificate file on the managed node. Default path is /etc/pki/tls/certs/ca.pem and the file name is set by the user.
    cert
    Represents the path to the certificate file on the managed node. Default path is /etc/pki/tls/certs/server-cert.pem and the file name is set by the user.
    private_key
    Represents the path to the private key file on the managed node. Default path is /etc/pki/tls/private/server-key.pem and the file name is set by the user.
    ca_cert_src
    Represents the path to the CA certificate file on the control node which is copied to the target host to the location specified by ca_cert. Do not use this if using logging_certificates.
    cert_src
    Represents the path to a certificate file on the control node which is copied to the target host to the location specified by cert. Do not use this if using logging_certificates.
    private_key_src
    Represents the path to a private key file on the control node which is copied to the target host to the location specified by private_key. Do not use this if using logging_certificates.
    tls
    Setting this parameter to true ensures secure transfer of logs over the network. If you do not want a secure wrapper, you can set tls: false.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.logging/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the logging RHEL system role to configure Reliable Event Logging Protocol (RELP) between a RELP client and RELP server.

RELP is a networking protocol for data and message logging over the TCP network. It ensures reliable delivery of event messages and you can use it in environments that do not tolerate any message loss.

The RELP sender transfers log entries in the form of commands and the receiver acknowledges them once they are processed. To ensure consistency, RELP stores the transaction number to each transferred command for any kind of message recovery.

15.4.1. Configuring client logging with RELP
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You can use the logging RHEL system role to configure a transfer of log messages stored locally to the remote logging system with RELP.

The RELP configuration uses Transport Layer Security (TLS) to encrypt the message transmission for secure transfer of logs over the network.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure client-side of the remote logging solution using RELP
  hosts: managed-node-01.example.com
  tasks:
    - name: Deploy basic input and RELP output
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.logging
      vars:
        logging_inputs:
          - name: basic_input
            type: basics
        logging_outputs:
          - name: relp_client
            type: relp
            target: logging.server.com
            port: 20514
            tls: true
            ca_cert: /etc/pki/tls/certs/ca.pem
            cert: /etc/pki/tls/certs/client-cert.pem
            private_key: /etc/pki/tls/private/client-key.pem
            pki_authmode: name
            permitted_servers:
              - '*.server.example.com'
        logging_flows:
          - name: example_flow
            inputs: [basic_input]
            outputs: [relp_client]
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    target
    This is a required parameter that specifies the host name where the remote logging system is running.
    port
    Port number the remote logging system is listening.
    tls

    Ensures secure transfer of logs over the network. If you do not want a secure wrapper you can set the tls variable to false. By default tls parameter is set to true while working with RELP and requires key/certificates and triplets {ca_cert, cert, private_key} and/or {ca_cert_src, cert_src, private_key_src}.

    • If the {ca_cert_src, cert_src, private_key_src} triplet is set, the default locations /etc/pki/tls/certs and /etc/pki/tls/private are used as the destination on the managed node to transfer files from control node. In this case, the file names are identical to the original ones in the triplet
    • If the {ca_cert, cert, private_key} triplet is set, files are expected to be on the default path before the logging configuration.
    • If both triplets are set, files are transferred from local path from control node to specific path of the managed node.
    ca_cert
    Represents the path to CA certificate. Default path is /etc/pki/tls/certs/ca.pem and the file name is set by the user.
    cert
    Represents the path to certificate. Default path is /etc/pki/tls/certs/server-cert.pem and the file name is set by the user.
    private_key
    Represents the path to private key. Default path is /etc/pki/tls/private/server-key.pem and the file name is set by the user.
    ca_cert_src
    Represents local CA certificate file path which is copied to the managed node. If ca_cert is specified, it is copied to the location.
    cert_src
    Represents the local certificate file path which is copied to the managed node. If cert is specified, it is copied to the location.
    private_key_src
    Represents the local key file path which is copied to the managed node. If private_key is specified, it is copied to the location.
    pki_authmode
    Accepts the authentication mode as name or fingerprint.
    permitted_servers
    List of servers that will be allowed by the logging client to connect and send logs over TLS.
    inputs
    List of logging input dictionary.
    outputs
    List of logging output dictionary.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.logging/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

15.4.2. Configuring server logging with RELP
Copy link

You can use the logging RHEL system role to configure a server for receiving log messages from the remote logging system with RELP.

The RELP configuration uses TLS to encrypt the message transmission for secure transfer of logs over the network.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure server-side of the remote logging solution using RELP
  hosts: managed-node-01.example.com
  tasks:
    - name: Deploying remote input and remote_files output
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.logging
      vars:
        logging_inputs:
          - name: relp_server
            type: relp
            port: 20514
            tls: true
            ca_cert: /etc/pki/tls/certs/ca.pem
            cert: /etc/pki/tls/certs/server-cert.pem
            private_key: /etc/pki/tls/private/server-key.pem
            pki_authmode: name
            permitted_clients:
              - '*client.example.com'
        logging_outputs:
          - name: remote_files_output
            type: remote_files
        logging_flows:
          - name: example_flow
            inputs: [relp_server]
            outputs: [remote_files_output]
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    port
    Port number the remote logging system is listening.
    tls

    Ensures secure transfer of logs over the network. If you do not want a secure wrapper you can set the tls variable to false. By default tls parameter is set to true while working with RELP and requires key/certificates and triplets {ca_cert, cert, private_key} and/or {ca_cert_src, cert_src, private_key_src}.

    • If the {ca_cert_src, cert_src, private_key_src} triplet is set, the default locations /etc/pki/tls/certs and /etc/pki/tls/private are used as the destination on the managed node to transfer files from control node. In this case, the file names are identical to the original ones in the triplet
    • If the {ca_cert, cert, private_key} triplet is set, files are expected to be on the default path before the logging configuration.
    • If both triplets are set, files are transferred from local path from control node to specific path of the managed node.
    ca_cert
    Represents the path to CA certificate. Default path is /etc/pki/tls/certs/ca.pem and the file name is set by the user.
    cert
    Represents the path to the certificate. Default path is /etc/pki/tls/certs/server-cert.pem and the file name is set by the user.
    private_key
    Represents the path to private key. Default path is /etc/pki/tls/private/server-key.pem and the file name is set by the user.
    ca_cert_src
    Represents local CA certificate file path which is copied to the managed node. If ca_cert is specified, it is copied to the location.
    cert_src
    Represents the local certificate file path which is copied to the managed node. If cert is specified, it is copied to the location.
    private_key_src
    Represents the local key file path which is copied to the managed node. If private_key is specified, it is copied to the location.
    pki_authmode
    Accepts the authentication mode as name or fingerprint.
    permitted_clients
    List of clients that will be allowed by the logging server to connect and send logs over TLS.
    inputs
    List of logging input dictionary.
    outputs
    List of logging output dictionary.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.logging/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Performance Co-Pilot (PCP) is a system performance analysis toolkit. You can use it to record and analyze performance data from many components on a RHEL system. Use the metrics RHEL system role to automate the installation and configuration of PCP, and configure Grafana to visualize PCP metrics.

You can use Performance Co-Pilot (PCP) to monitor many metrics, such as CPU utilization and memory usage. For example, this can help to identify resource and performance bottlenecks. By using the metrics RHEL system role, you can remotely configure PCP on multiple hosts to record metrics.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Monitoring performance metrics
  hosts: managed-node-01.example.com
  tasks:
    - name: Configure Performance Co-Pilot
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.metrics
      vars:
        metrics_retention_days: 14
        metrics_manage_firewall: true
        metrics_manage_selinux: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    metrics_retention_days: <number>
    Sets the number of days after which the pmlogger_daily systemd timer removes old PCP archives.
    metrics_manage_firewall: <true|false>
    Defines whether the role should open the required ports in the firewalld service. If you want to remotely access PCP on the managed nodes, set this variable to true.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.metrics/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Query a metric, for example: 

    # ansible managed-node-01.example.com -m command -a 'pminfo -f kernel.all.load'
    Copy to Clipboard Toggle word wrap

Next step

You can use the metrics RHEL system role to remotely configure Performance Co-Pilot (PCP) with authentication on multiple hosts.

You can enable authentication in PCP so that the pmcd service and Performance Metrics Domain Agents (PDMAs) can determine whether the user running the monitoring tools is allowed to perform an action. Authenticated users have access to metrics with sensitive information. Additionally, certain agents require authentication. For example, the bpftrace agent uses authentication to identify whether a user is allowed to load bpftrace scripts into the kernel to generate metrics.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      metrics_usr: <username>
metrics_pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Monitoring performance metrics
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Configure Performance Co-Pilot
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.metrics
      vars:
        metrics_retention_days: 14
        metrics_manage_firewall: true
        metrics_manage_selinux: true
        metrics_username: "{{ metrics_usr }}"
        metrics_password: "{{ metrics_pwd }}"
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    metrics_retention_days: <number>
    Sets the number of days after which the pmlogger_daily systemd timer removes old PCP archives.
    metrics_manage_firewall: <true|false>
    Defines whether the role should open the required ports in the firewalld service. If you want to remotely access PCP on the managed nodes, set this variable to true.
    metrics_username: <username>
    The role creates this user locally on the managed node, adds the credentials to the /etc/pcp/passwd.db Simple Authentication and Security Layer (SASL) database, and configures authentication in PCP. Additionally, if you set metrics_from_bpftrace: true in the playbook, PCP uses this account to register bpftrace scripts.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.metrics/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • On a host with the pcp package installed, query a metric that requires authentication:

    1. Query the metrics by using the credentials that you used in the playbook: 

      # pminfo -fmdt -h pcp://managed-node-01.example.com?username=<user> proc.fd.count
Password: <password>

proc.fd.count
    inst [844 or "000844 /var/lib/pcp/pmdas/proc/pmdaproc"] value 5
      Copy to Clipboard Toggle word wrap

      If the command succeeds, it returns the value of the proc.fd.count metric.

    2. Run the command again, but omit the username to verify that the command fails for unauthenticated users: 

      # pminfo -fmdt -h pcp://managed-node-01.example.com proc.fd.count

proc.fd.count
Error: No permission to perform requested operation
      Copy to Clipboard Toggle word wrap

Next step

If you have configured Performance Co-Pilot (PCP) on multiple hosts, you can use Grafana to visualize the metrics for these hosts. By using the metrics RHEL system role, you can automate the process of setting up Grafana, the PCP plug-in, and the configuration of the data sources.

Note

If you use the metrics role to install Grafana on a host, the role also installs automatically PCP on this host.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      grafana_admin_pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Monitoring performance metrics
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Set up Grafana to monitor multiple hosts
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.metrics
      vars:
        metrics_graph_service: true
        metrics_query_service: true
        metrics_monitored_hosts:
          - <pcp_host_1.example.com>
          - <pcp_host_2.example.com>
        metrics_manage_firewall: true
        metrics_manage_selinux: true

    - name: Set Grafana admin password
      ansible.builtin.shell:
        cmd: grafana-cli admin reset-admin-password "{{ grafana_admin_pwd }}"
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    metrics_graph_service: true
    Installs Grafana and the PCP plug-in. Additionally, the role adds the PCP Vector, PCP Redis, and PCP bpftrace data sources to Grafana.
    metrics_query_service: <true|false>
    Defines whether the role should install and configure Redis for centralized metric recording. If enabled, data collected from PCP clients is stored in Redis and, as a result, you can also display historical data instead of only live data.
    metrics_monitored_hosts: <list_of_hosts>
    Defines the list of hosts to monitor. In Grafana, you can then display the data of these hosts and, additionally, the host that runs Grafana.
    metrics_manage_firewall: <true|false>
    Defines whether the role should open the required ports in the firewalld service. If you set this variable to true, you can, for example, access Grafana remotely.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.metrics/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. Open http://<grafana_server_IP_or_hostname>:3000 in your browser, and log in as the admin user with the password you set in the procedure.

  2. Display monitoring data:

    • To display live data:

      1. Click Menu → Apps → Performance Co-Pilot → PCP Vector Checklist
      2. By default, the graphs display metrics from the host that runs Grafana. To switch to a different host, enter the hostname in the hostspec field and press Enter.
    • To display historical data stored in a Redis database: Create a panel with a PCP Redis data source. This requires that you set metrics_query_service: true in the playbook.

The Performance Co-Pilot (PCP) suite contains the performance metrics inference engine (PMIE) service. This service evaluates performance rules in real time. For example, you can use the default rules to detect excessive swap activities.

You can configure a host as a central PCP management site that collects the monitoring data from multiple PCP nodes. If a rule matches, this central host sends a notification to a web hook to notify other services. For example, the web hook can trigger Event-Driven Ansible to run on Ansible Automation Platform template or playbook on the host that had caused the event.

By using the metrics RHEL system role, you can automate the configuration of a central PCP management host that notifies a web hook.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Monitoring performance metrics
  hosts: managed-node-01.example.com
  tasks:
    - name: Configure PMIE web hooks
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.metrics
      vars:
        metrics_manage_firewall: true
        metrics_retention_days: 7
        metrics_monitored_hosts:
          - pcp-node-01.example.com
          - pcp-node-02.example.com
        metrics_webhook_endpoint: "https://<webserver>:<port>/<endpoint>"
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    metrics_retention_days: <number>
    Sets the number of days after which the pmlogger_daily systemd timer removes old PCP archives.
    metrics_manage_firewall: <true|false>
    Defines whether the role should open the required ports in the firewalld service. If you want to remotely access PCP on the managed nodes, set this variable to true.
    metrics_monitored_hosts: <list_of_hosts>
    Specifies the hosts to observe.
    metrics_webhook_endpoint: <URL>
    Sets the web hook endpoint to which the performance metrics inference engine (PMIE) sends notifications about detected performance issues. By default, these issues are logged to the local system only.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.metrics/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. Check the configuration summary on managed-node-node-01.example.com: 

    # ansible managed-node-01.example.com -m command -a 'pcp summary'
Performance Co-Pilot configuration on managed-node-01.example.com:

 platform: Linux managed-node-node-01.example.com 5.14.0-427.el9.x86_64 #1 SMP PREEMPT_DYNAMIC Fri Feb 23 01:51:18 EST 2024 x86_64
 hardware: 8 cpus, 1 disk, 1 node, 1773MB RAM
 timezone: CEST-2
 services: pmcd pmproxy
 pmcd: Version 6.2.0-1, 12 agents, 6 clients
 pmda: root pmcd proc pmproxy xfs linux nfsclient mmv kvm jbd2
       dm openmetrics
 pmlogger: primary logger: /var/log/pcp/pmlogger/managed-node-node-01.example.com/20240510.16.25
           pcp-node-01.example.com: /var/log/pmlogger/pcp-node-01.example.com/20240510.16.25
           pcp-node-02.example.com: /var/log/pmlogger/pcp-node-02.example.com/20240510.16.25
 pmie: primary engine: /var/log/pcp/pmie/managed-node-node-01.example.com/pmie.log
       pcp-node-01.example.com: : /var/log/pcp/pmie/pcp-node-01.example.com/pmie.log
       pcp-node-02.example.com: : /var/log/pcp/pmie/pcp-node-02.example.com/pmie.log
    Copy to Clipboard Toggle word wrap

    The last three lines confirm that PMIE is configured to monitor three systems.

You can use the nbde_client and nbde_server RHEL system roles for automated deployments of Policy-Based Decryption (PBD) solutions by using Clevis and Tang.

The rhel-system-roles package contains these system roles, the related examples, and the reference documentation.

By using the nbde_server system role, you can deploy and manage a Tang server as part of an automated disk encryption solution.

This role supports the following features:

  • Rotating Tang keys
  • Deploying and backing up Tang keys

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Deploy a Tang server
  hosts: tang.server.example.com
  tasks:
  - name: Install and configure periodic key rotation
    ansible.builtin.include_role:
        name: redhat.rhel_system_roles.nbde_server
    vars:
      nbde_server_rotate_keys: yes
      nbde_server_manage_firewall: true
      nbde_server_manage_selinux: true
    Copy to Clipboard Toggle word wrap

    This example playbook ensures deploying of your Tang server and a key rotation.

    The settings specified in the example playbook include the following:

    nbde_server_manage_firewall: true
    Use the firewall system role to manage ports used by the nbde_server role.
    nbde_server_manage_selinux: true

    Use the selinux system role to manage ports used by the nbde_server role.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.nbde_server/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • On your NBDE client, verify that your Tang server works correctly by using the following command. The command must return the identical message you pass for encryption and decryption: 

    # ansible managed-node-01.example.com -m command -a 'echo test | clevis encrypt tang '{"url":"<tang.server.example.com>"}' -y | clevis decrypt'
test
    Copy to Clipboard Toggle word wrap

The nbde_client system role enables you to deploy multiple Clevis clients in an automated way.

This role supports binding a LUKS-encrypted volume to one or more Network-Bound (NBDE) servers - Tang servers. You can either preserve the existing volume encryption with a passphrase or remove it. After removing the passphrase, you can unlock the volume only using NBDE. This is useful when a volume is initially encrypted using a temporary key or password that you should remove after you provision the system.

If you provide both a passphrase and a key file, the role uses what you have provided first. If it does not find any of these valid, it attempts to retrieve a passphrase from an existing binding.

Policy-Based Decryption (PBD) defines a binding as a mapping of a device to a slot. This means that you can have multiple bindings for the same device. The default slot is slot 1.

Note

The nbde_client system role supports only Tang bindings. Therefore, you cannot use it for TPM2 bindings.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • A volume that is already encrypted by using LUKS.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure clients for unlocking of encrypted volumes by Tang servers
  hosts: managed-node-01.example.com
  tasks:
    - name: Create NBDE client bindings
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.nbde_client
      vars:
        nbde_client_bindings:
          - device: /dev/rhel/root
            encryption_key_src: /etc/luks/keyfile
            nbde_client_early_boot: true
            state: present
            servers:
              - http://server1.example.com
              - http://server2.example.com
          - device: /dev/rhel/swap
            encryption_key_src: /etc/luks/keyfile
            servers:
              - http://server1.example.com
              - http://server2.example.com
    Copy to Clipboard Toggle word wrap

    This example playbook configures Clevis clients for automated unlocking of two LUKS-encrypted volumes when at least one of two Tang servers is available.

    The settings specified in the example playbook include the following:

    state: present
    The values of state indicate the configuration after you run the playbook. Use the present value for either creating a new binding or updating an existing one. Contrary to a clevis luks bind command, you can use state: present also for overwriting an existing binding in its device slot. The absent value removes a specified binding.
    nbde_client_early_boot: true

    The nbde_client role ensures that networking for a Tang pin is available during early boot by default. If you scenario requires to disable this feature, add the nbde_client_early_boot: false variable to your playbook.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.nbde_client/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. On your NBDE client, check that the encrypted volume that should be automatically unlocked by your Tang servers contain the corresponding information in its LUKS pins: 

    # ansible managed-node-01.example.com -m command -a 'clevis luks list -d /dev/rhel/root'
1: tang '{"url":"<http://server1.example.com/>"}'
2: tang '{"url":"<http://server2.example.com/>"}'
    Copy to Clipboard Toggle word wrap

  2. If you do not use the nbde_client_early_boot: false variable, verify that the bindings are available for the early boot, for example: 

    # ansible managed-node-01.example.com -m command -a 'lsinitrd | grep clevis-luks'
lrwxrwxrwx   1 root     root           48 Jan  4 02:56 etc/systemd/system/cryptsetup.target.wants/clevis-luks-askpass.path -> /usr/lib/systemd/system/clevis-luks-askpass.path
…
    Copy to Clipboard Toggle word wrap

The nbde_client RHEL system role supports only scenarios with Dynamic Host Configuration Protocol (DHCP). On an NBDE client with static IP configuration, you must pass your network configuration as a kernel boot parameter.

Typically, administrators want to reuse a playbook and not maintain individual playbooks for each host to which Ansible assigns static IP addresses during early boot. In this case, you can use variables in the playbook and provide the settings in an external file. As a result, you need only one playbook and one file with the settings.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • A volume that is already encrypted by using LUKS.

Procedure

  1. Create a file with the network settings of your hosts, for example, static-ip-settings-clients.yml, and add the values you want to dynamically assign to the hosts: 

    clients:
  managed-node-01.example.com:
    ip_v4: 192.0.2.1
    gateway_v4: 192.0.2.254
    netmask_v4: 255.255.255.0
    interface: enp1s0
  managed-node-02.example.com:
    ip_v4: 192.0.2.2
    gateway_v4: 192.0.2.254
    netmask_v4: 255.255.255.0
    interface: enp1s0
    Copy to Clipboard Toggle word wrap

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    - name: Configure clients for unlocking of encrypted volumes by Tang servers
  hosts: managed-node-01.example.com,managed-node-02.example.com
  vars_files:
    - ~/static-ip-settings-clients.yml
  tasks:
    - name: Create NBDE client bindings
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        nbde_client_bindings:
          - device: /dev/rhel/root
            encryption_key_src: /etc/luks/keyfile
            servers:
              - http://server1.example.com
              - http://server2.example.com
          - device: /dev/rhel/swap
            encryption_key_src: /etc/luks/keyfile
            servers:
              - http://server1.example.com
              - http://server2.example.com

    - name: Configure a Clevis client with static IP address during early boot
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.bootloader
      vars:
        bootloader_settings:
          - kernel: ALL
            options:
              - name: ip
                value: "{{ clients[inventory_hostname]['ip_v4'] }}::{{ clients[inventory_hostname]['gateway_v4'] }}:{{ clients[inventory_hostname]['netmask_v4'] }}::{{ clients[inventory_hostname]['interface'] }}:none"
    Copy to Clipboard Toggle word wrap

    This playbook reads certain values dynamically for each host listed in the ~/static-ip-settings-clients.yml file.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

By using the network RHEL system role, you can automate network-related configuration and management tasks.

You can use the network RHEL system role to configure an Ethernet connection with static IP addresses, gateways, and DNS settings, and assign them to a specified interface name.

To connect a Red Hat Enterprise Linux host to an Ethernet network, create a NetworkManager connection profile for the network device. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

Typically, administrators want to reuse a playbook and not maintain individual playbooks for each host to which Ansible should assign static IP addresses. In this case, you can use variables in the playbook and maintain the settings in the inventory. As a result, you need only one playbook to dynamically assign individual settings to multiple hosts.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • A physical or virtual Ethernet device exists in the server configuration.
  • The managed nodes use NetworkManager to configure the network.

Procedure

  1. Edit the ~/inventory file, and append the host-specific settings to the host entries: 

    managed-node-01.example.com interface=enp1s0 ip_v4=192.0.2.1/24 ip_v6=2001:db8:1::1/64 gateway_v4=192.0.2.254 gateway_v6=2001:db8:1::fffe

managed-node-02.example.com interface=enp1s0 ip_v4=192.0.2.2/24 ip_v6=2001:db8:1::2/64 gateway_v4=192.0.2.254 gateway_v6=2001:db8:1::fffe
    Copy to Clipboard Toggle word wrap

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the network
  hosts: managed-node-01.example.com,managed-node-02.example.com
  tasks:
    - name: Ethernet connection profile with static IP address settings
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          - name: "{{ interface }}"
            interface_name: "{{ interface }}"
            type: ethernet
            autoconnect: yes
            ip:
              address:
                - "{{ ip_v4 }}"
                - "{{ ip_v6 }}"
              gateway4: "{{ gateway_v4 }}"
              gateway6: "{{ gateway_v6 }}"
              dns:
                - 192.0.2.200
                - 2001:db8:1::ffbb
              dns_search:
                - example.com
            state: up
    Copy to Clipboard Toggle word wrap

    This playbook reads certain values dynamically for each host from the inventory file and uses static values in the playbook for settings which are the same for all hosts.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Query the Ansible facts of the managed node and verify the active network settings: 

    # ansible managed-node-01.example.com -m ansible.builtin.setup
...
        "ansible_default_ipv4": {
            "address": "192.0.2.1",
            "alias": "enp1s0",
            "broadcast": "192.0.2.255",
            "gateway": "192.0.2.254",
            "interface": "enp1s0",
            "macaddress": "52:54:00:17:b8:b6",
            "mtu": 1500,
            "netmask": "255.255.255.0",
            "network": "192.0.2.0",
            "prefix": "24",
            "type": "ether"
        },
        "ansible_default_ipv6": {
            "address": "2001:db8:1::1",
            "gateway": "2001:db8:1::fffe",
            "interface": "enp1s0",
            "macaddress": "52:54:00:17:b8:b6",
            "mtu": 1500,
            "prefix": "64",
            "scope": "global",
            "type": "ether"
        },
        ...
        "ansible_dns": {
            "nameservers": [
                "192.0.2.1",
                "2001:db8:1::ffbb"
            ],
            "search": [
                "example.com"
            ]
        },
...
    Copy to Clipboard Toggle word wrap

You can use the network RHEL system role to configure an Ethernet connection with static IP addresses, gateways, and DNS settings, and assign them to a device based on its path instead of its name.

To connect a Red Hat Enterprise Linux host to an Ethernet network, create a NetworkManager connection profile for the network device. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • A physical or virtual Ethernet device exists in the server’s configuration.
  • The managed nodes use NetworkManager to configure the network.
  • You know the path of the device. You can display the device path by using the udevadm info /sys/class/net/<device_name> | grep ID_PATH= command.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the network
  hosts: managed-node-01.example.com
  tasks:
    - name: Ethernet connection profile with static IP address settings
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          - name: example
            match:
              path:
                - pci-0000:00:0[1-3].0
                - '&!pci-0000:00:02.0'
            type: ethernet
            autoconnect: yes
            ip:
              address:
                - 192.0.2.1/24
                - 2001:db8:1::1/64
              gateway4: 192.0.2.254
              gateway6: 2001:db8:1::fffe
              dns:
                - 192.0.2.200
                - 2001:db8:1::ffbb
              dns_search:
                - example.com
            state: up
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    match
    Defines that a condition must be met in order to apply the settings. You can only use this variable with the path option.
    path
    Defines the persistent path of a device. You can set it as a fixed path or an expression. Its value can contain modifiers and wildcards. The example applies the settings to devices that match PCI ID 0000:00:0[1-3].0, but not 0000:00:02.0.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Query the Ansible facts of the managed node and verify the active network settings: 

    # ansible managed-node-01.example.com -m ansible.builtin.setup
...
        "ansible_default_ipv4": {
            "address": "192.0.2.1",
            "alias": "enp1s0",
            "broadcast": "192.0.2.255",
            "gateway": "192.0.2.254",
            "interface": "enp1s0",
            "macaddress": "52:54:00:17:b8:b6",
            "mtu": 1500,
            "netmask": "255.255.255.0",
            "network": "192.0.2.0",
            "prefix": "24",
            "type": "ether"
        },
        "ansible_default_ipv6": {
            "address": "2001:db8:1::1",
            "gateway": "2001:db8:1::fffe",
            "interface": "enp1s0",
            "macaddress": "52:54:00:17:b8:b6",
            "mtu": 1500,
            "prefix": "64",
            "scope": "global",
            "type": "ether"
        },
        ...
        "ansible_dns": {
            "nameservers": [
                "192.0.2.1",
                "2001:db8:1::ffbb"
            ],
            "search": [
                "example.com"
            ]
        },
...
    Copy to Clipboard Toggle word wrap

You can use the network RHEL system role to configure an Ethernet connection that retrieves its IP addresses, gateways, and DNS settings from a DHCP server and IPv6 stateless address autoconfiguration (SLAAC). With this role you can assign the connection profile to the specified interface name.

To connect a Red Hat Enterprise Linux host to an Ethernet network, create a NetworkManager connection profile for the network device. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • A physical or virtual Ethernet device exists in the servers' configuration.
  • A DHCP server and SLAAC are available in the network.
  • The managed nodes use the NetworkManager service to configure the network.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the network
  hosts: managed-node-01.example.com
  tasks:
    - name: Ethernet connection profile with dynamic IP address settings
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          - name: enp1s0
            interface_name: enp1s0
            type: ethernet
            autoconnect: yes
            ip:
              dhcp4: yes
              auto6: yes
            state: up
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    dhcp4: yes
    Enables automatic IPv4 address assignment from DHCP, PPP, or similar services.
    auto6: yes
    Enables IPv6 auto-configuration. By default, NetworkManager uses Router Advertisements. If the router announces the managed flag, NetworkManager requests an IPv6 address and prefix from a DHCPv6 server.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Query the Ansible facts of the managed node and verify that the interface received IP addresses and DNS settings: 

    # ansible managed-node-01.example.com -m ansible.builtin.setup
...
        "ansible_default_ipv4": {
            "address": "192.0.2.1",
            "alias": "enp1s0",
            "broadcast": "192.0.2.255",
            "gateway": "192.0.2.254",
            "interface": "enp1s0",
            "macaddress": "52:54:00:17:b8:b6",
            "mtu": 1500,
            "netmask": "255.255.255.0",
            "network": "192.0.2.0",
            "prefix": "24",
            "type": "ether"
        },
        "ansible_default_ipv6": {
            "address": "2001:db8:1::1",
            "gateway": "2001:db8:1::fffe",
            "interface": "enp1s0",
            "macaddress": "52:54:00:17:b8:b6",
            "mtu": 1500,
            "prefix": "64",
            "scope": "global",
            "type": "ether"
        },
        ...
        "ansible_dns": {
            "nameservers": [
                "192.0.2.1",
                "2001:db8:1::ffbb"
            ],
            "search": [
                "example.com"
            ]
        },
...
    Copy to Clipboard Toggle word wrap

By using the network RHEL system role, you can configure an Ethernet connection to retrieve its IP addresses, gateways, and DNS settings from a DHCP server and IPv6 stateless address autoconfiguration (SLAAC). The role can assign the profile by the device’s path.

To connect a Red Hat Enterprise Linux host to an Ethernet network, create a NetworkManager connection profile for the network device. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • A physical or virtual Ethernet device exists in the server’s configuration.
  • A DHCP server and SLAAC are available in the network.
  • The managed hosts use NetworkManager to configure the network.
  • You know the path of the device. You can display the device path by using the udevadm info /sys/class/net/<device_name> | grep ID_PATH= command.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the network
  hosts: managed-node-01.example.com
  tasks:
    - name: Ethernet connection profile with dynamic IP address settings
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          - name: example
            match:
              path:
                - pci-0000:00:0[1-3].0
                - '&!pci-0000:00:02.0'
            type: ethernet
            autoconnect: yes
            ip:
              dhcp4: yes
              auto6: yes
            state: up
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    match: path
    Defines that a condition must be met in order to apply the settings. You can only use this variable with the path option.
    path: <path_and_expressions>
    Defines the persistent path of a device. You can set it as a fixed path or an expression. Its value can contain modifiers and wildcards. The example applies the settings to devices that match PCI ID 0000:00:0[1-3].0, but not 0000:00:02.0.
    dhcp4: yes
    Enables automatic IPv4 address assignment from DHCP, PPP, or similar services.
    auto6: yes
    Enables IPv6 auto-configuration. By default, NetworkManager uses Router Advertisements. If the router announces the managed flag, NetworkManager requests an IPv6 address and prefix from a DHCPv6 server.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Query the Ansible facts of the managed node and verify that the interface received IP addresses and DNS settings: 

    # ansible managed-node-01.example.com -m ansible.builtin.setup
...
        "ansible_default_ipv4": {
            "address": "192.0.2.1",
            "alias": "enp1s0",
            "broadcast": "192.0.2.255",
            "gateway": "192.0.2.254",
            "interface": "enp1s0",
            "macaddress": "52:54:00:17:b8:b6",
            "mtu": 1500,
            "netmask": "255.255.255.0",
            "network": "192.0.2.0",
            "prefix": "24",
            "type": "ether"
        },
        "ansible_default_ipv6": {
            "address": "2001:db8:1::1",
            "gateway": "2001:db8:1::fffe",
            "interface": "enp1s0",
            "macaddress": "52:54:00:17:b8:b6",
            "mtu": 1500,
            "prefix": "64",
            "scope": "global",
            "type": "ether"
        },
        ...
        "ansible_dns": {
            "nameservers": [
                "192.0.2.1",
                "2001:db8:1::ffbb"
            ],
            "search": [
                "example.com"
            ]
        },
...
    Copy to Clipboard Toggle word wrap

By using the network RHEL system role, you can automate setting up Network Access Control (NAC) on remote hosts. You can define authentication details for clients in a playbook to ensure only authorized clients can access the network.

You can use an Ansible playbook to copy a private key, a certificate, and the CA certificate to the client, and then use the network RHEL system role to configure a connection profile with 802.1X network authentication.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The network supports 802.1X network authentication.
  • The managed nodes use NetworkManager.

  • The following files required for the TLS authentication exist on the control node:

    • The client key is stored in the /srv/data/client.key file.
    • The client certificate is stored in the /srv/data/client.crt file.
    • The Certificate Authority (CA) certificate is stored in the /srv/data/ca.crt file.

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure an Ethernet connection with 802.1X authentication
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Copy client key for 802.1X authentication
      ansible.builtin.copy:
        src: "/srv/data/client.key"
        dest: "/etc/pki/tls/private/client.key"
        mode: 0600

    - name: Copy client certificate for 802.1X authentication
      ansible.builtin.copy:
        src: "/srv/data/client.crt"
        dest: "/etc/pki/tls/certs/client.crt"

    - name: Copy CA certificate for 802.1X authentication
      ansible.builtin.copy:
        src: "/srv/data/ca.crt"
        dest: "/etc/pki/ca-trust/source/anchors/ca.crt"

    - name: Ethernet connection profile with static IP address settings and 802.1X
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          - name: enp1s0
            type: ethernet
            autoconnect: yes
            ip:
              address:
                - 192.0.2.1/24
                - 2001:db8:1::1/64
              gateway4: 192.0.2.254
              gateway6: 2001:db8:1::fffe
              dns:
                - 192.0.2.200
                - 2001:db8:1::ffbb
              dns_search:
                - example.com
            ieee802_1x:
              identity: <user_name>
              eap: tls
              private_key: "/etc/pki/tls/private/client.key"
              private_key_password: "{{ pwd }}"
              client_cert: "/etc/pki/tls/certs/client.crt"
              ca_cert: "/etc/pki/ca-trust/source/anchors/ca.crt"
              domain_suffix_match: example.com
            state: up
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ieee802_1x
    This variable contains the 802.1X-related settings.
    eap: tls
    Configures the profile to use the certificate-based TLS authentication method for the Extensible Authentication Protocol (EAP).

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Access resources on the network that require network authentication.

By using the network RHEL system role, you can automate setting up Network Access Control (NAC) on remote hosts. You can define authentication details for clients in a playbook to ensure only authorized clients can access the network.

You can use an Ansible playbook to copy a private key, a certificate, and the CA certificate to the client, and then use the network RHEL system role to configure a connection profile with 802.1X network authentication.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The network supports 802.1X network authentication.
  • You installed the wpa_supplicant package on the managed node.
  • DHCP is available in the network of the managed node.

  • The following files required for TLS authentication exist on the control node:

    • The client key is stored in the /srv/data/client.key file.
    • The client certificate is stored in the /srv/data/client.crt file.
    • The CA certificate is stored in the /srv/data/ca.crt file.

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure a wifi connection with 802.1X authentication
  hosts: managed-node-01.example.com
  tasks:
    - name: Copy client key for 802.1X authentication
      ansible.builtin.copy:
        src: "/srv/data/client.key"
        dest: "/etc/pki/tls/private/client.key"
        mode: 0400

    - name: Copy client certificate for 802.1X authentication
      ansible.builtin.copy:
        src: "/srv/data/client.crt"
        dest: "/etc/pki/tls/certs/client.crt"

    - name: Copy CA certificate for 802.1X authentication
      ansible.builtin.copy:
        src: "/srv/data/ca.crt"
        dest: "/etc/pki/ca-trust/source/anchors/ca.crt"

    - name: Wifi connection profile with dynamic IP address settings and 802.1X
      ansible.builtin.import_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          - name: Wifi connection profile with dynamic IP address settings and 802.1X
            interface_name: wlp1s0
            state: up
            type: wireless
            autoconnect: yes
            ip:
              dhcp4: true
              auto6: true
            wireless:
              ssid: "Example-wifi"
              key_mgmt: "wpa-eap"
            ieee802_1x:
              identity: <user_name>
              eap: tls
              private_key: "/etc/pki/tls/client.key"
              private_key_password: "{{ pwd }}"
              private_key_password_flags: none
              client_cert: "/etc/pki/tls/client.pem"
              ca_cert: "/etc/pki/tls/cacert.pem"
              domain_suffix_match: "example.com"
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ieee802_1x
    This variable contains the 802.1X-related settings.
    eap: tls
    Configures the profile to use the certificate-based TLS authentication method for the Extensible Authentication Protocol (EAP).

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the network RHEL system role to configure a network bond and, if a connection profile for the bond’s parent device does not exist, the role can create it as well.

You can combine network interfaces in a bond to provide a logical interface with higher throughput or redundancy. To configure a bond, create a NetworkManager connection profile. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • Two or more physical or virtual network devices are installed on the server.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the network
  hosts: managed-node-01.example.com
  tasks:
    - name: Bond connection profile with two Ethernet ports
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          # Bond profile
          - name: bond0
            type: bond
            interface_name: bond0
            ip:
              dhcp4: yes
              auto6: yes
            bond:
              mode: active-backup
            state: up

          # Port profile for the 1st Ethernet device
          - name: bond0-port1
            interface_name: enp7s0
            type: ethernet
            controller: bond0
            state: up

          # Port profile for the 2nd Ethernet device
          - name: bond0-port2
            interface_name: enp8s0
            type: ethernet
            controller: bond0
            state: up
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    type: <profile_type>
    Sets the type of the profile to create. The example playbook creates three connection profiles: One for the bond and two for the Ethernet devices.
    dhcp4: yes
    Enables automatic IPv4 address assignment from DHCP, PPP, or similar services.
    auto6: yes
    Enables IPv6 auto-configuration. By default, NetworkManager uses Router Advertisements. If the router announces the managed flag, NetworkManager requests an IPv6 address and prefix from a DHCPv6 server.
    mode: <bond_mode>

    Sets the bonding mode. Possible values are:

    • balance-rr (default)
    • active-backup
    • balance-xor
    • broadcast
    • 802.3ad
    • balance-tlb
    • balance-alb.

    Depending on the mode you set, you need to set additional variables in the playbook.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Temporarily remove the network cable from one of the network devices and check if the other device in the bond is handling the traffic.

    Note that there is no method to properly test link failure events using software utilities. Tools that deactivate connections, such as nmcli, show only the bonding driver’s ability to handle port configuration changes and not actual link failure events.

You can use the network RHEL system role to configure VLAN tagging and, if a connection profile for the VLAN’s parent device does not exist, the role can create it as well.

If your network uses Virtual Local Area Networks (VLANs) to separate network traffic into logical networks, create a NetworkManager connection profile to configure VLAN tagging. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

Note

If the VLAN device requires an IP address, default gateway, and DNS settings, configure them on the VLAN device and not on the parent device.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the network
  hosts: managed-node-01.example.com
  tasks:
    - name: VLAN connection profile with Ethernet port
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          # Ethernet profile
          - name: enp1s0
            type: ethernet
            interface_name: enp1s0
            autoconnect: yes
            state: up
            ip:
              dhcp4: no
              auto6: no

          # VLAN profile
          - name: enp1s0.10
            type: vlan
            vlan:
              id: 10
            ip:
              dhcp4: yes
              auto6: yes
            parent: enp1s0
            state: up
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    type: <profile_type>
    Sets the type of the profile to create. The example playbook creates two connection profiles: One for the parent Ethernet device and one for the VLAN device.
    dhcp4: <value>
    If set to yes, automatic IPv4 address assignment from DHCP, PPP, or similar services is enabled. Disable the IP address configuration on the parent device.
    auto6: <value>
    If set to yes, IPv6 auto-configuration is enabled. In this case, by default, NetworkManager uses Router Advertisements and, if the router announces the managed flag, NetworkManager requests an IPv6 address and prefix from a DHCPv6 server. Disable the IP address configuration on the parent device.
    parent: <parent_device>
    Sets the parent device of the VLAN connection profile. In the example, the parent is the Ethernet interface.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Verify the VLAN settings: 

    # ansible managed-node-01.example.com -m command -a 'ip -d addr show enp1s0.10'
managed-node-01.example.com | CHANGED | rc=0 >>
4: vlan10@enp1s0.10: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 52:54:00:72:2f:6e brd ff:ff:ff:ff:ff:ff promiscuity 0
    vlan protocol 802.1Q id 10 <REORDER_HDR> numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
    ...
    Copy to Clipboard Toggle word wrap

You can use the network RHEL system role to configure a bridge and, if a connection profile for the bridge’s parent device does not exist, the role can create it as well.

You can connect multiple networks on layer 2 of the Open Systems Interconnection (OSI) model by creating a network bridge. To configure a bridge, create a connection profile in NetworkManager. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

Note

If you want to assign IP addresses, gateways, and DNS settings to a bridge, configure them on the bridge and not on its ports.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • Two or more physical or virtual network devices are installed on the server.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the network
  hosts: managed-node-01.example.com
  tasks:
    - name: Bridge connection profile with two Ethernet ports
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          # Bridge profile
          - name: bridge0
            type: bridge
            interface_name: bridge0
            ip:
              dhcp4: yes
              auto6: yes
            state: up

          # Port profile for the 1st Ethernet device
          - name: bridge0-port1
            interface_name: enp7s0
            type: ethernet
            controller: bridge0
            port_type: bridge
            state: up

          # Port profile for the 2nd Ethernet device
          - name: bridge0-port2
            interface_name: enp8s0
            type: ethernet
            controller: bridge0
            port_type: bridge
            state: up
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    type: <profile_type>
    Sets the type of the profile to create. The example playbook creates three connection profiles: One for the bridge and two for the Ethernet devices.
    dhcp4: yes
    Enables automatic IPv4 address assignment from DHCP, PPP, or similar services.
    auto6: yes
    Enables IPv6 auto-configuration. By default, NetworkManager uses Router Advertisements. If the router announces the managed flag, NetworkManager requests an IPv6 address and prefix from a DHCPv6 server.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. Display the link status of Ethernet devices that are ports of a specific bridge: 

    # ansible managed-node-01.example.com -m command -a 'ip link show master bridge0'
managed-node-01.example.com | CHANGED | rc=0 >>
3: enp7s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master bridge0 state UP mode DEFAULT group default qlen 1000
    link/ether 52:54:00:62:61:0e brd ff:ff:ff:ff:ff:ff
4: enp8s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master bridge0 state UP mode DEFAULT group default qlen 1000
    link/ether 52:54:00:9e:f1:ce brd ff:ff:ff:ff:ff:ff
    Copy to Clipboard Toggle word wrap

  2. Display the status of Ethernet devices that are ports of any bridge device: 

    # ansible managed-node-01.example.com -m command -a 'bridge link show'
managed-node-01.example.com | CHANGED | rc=0 >>
3: enp7s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master bridge0 state forwarding priority 32 cost 100
4: enp8s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master bridge0 state listening priority 32 cost 100
    Copy to Clipboard Toggle word wrap

By using the network RHEL system role, you can automate setting the default gateway in a NetworkManager connection profile. With this method, you can remotely configure the default gateway on hosts defined in a playbook.

In most situations, administrators set the default gateway when they create a connection. However, you can also set or update the default gateway setting on a previously-created connection.

Warning

You cannot use the network RHEL system role to update only specific values in an existing connection profile. The role ensures that a connection profile exactly matches the settings in a playbook. If a connection profile with the same name already exists, the role applies the settings from the playbook and resets all other settings in the profile to their defaults. To prevent resetting values, always specify the whole configuration of the network connection profile in the playbook, including the settings that you do not want to change.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the network
  hosts: managed-node-01.example.com
  tasks:
    - name: Ethernet connection profile with static IP address settings
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          - name: enp1s0
            type: ethernet
            autoconnect: yes
            ip:
              address:
                - 198.51.100.20/24
                - 2001:db8:1::1/64
              gateway4: 198.51.100.254
              gateway6: 2001:db8:1::fffe
              dns:
                - 198.51.100.200
                - 2001:db8:1::ffbb
              dns_search:
                - example.com
            state: up
    Copy to Clipboard Toggle word wrap

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Query the Ansible facts of the managed node and verify the active network settings: 

    # ansible managed-node-01.example.com -m ansible.builtin.setup
...
        "ansible_default_ipv4": {
	    ...
            "gateway": "198.51.100.254",
            "interface": "enp1s0",
	    ...
        },
        "ansible_default_ipv6": {
	    ...
            "gateway": "2001:db8:1::fffe",
            "interface": "enp1s0",
	    ...
	}
...
    Copy to Clipboard Toggle word wrap

You can use the network RHEL system role to configure static routes.

Important

When you run a play that uses the network RHEL system role and if the setting values do not match the values specified in the play, the role overrides the existing connection profile with the same name. To prevent resetting these values to their defaults, always specify the whole configuration of the network connection profile in the play, even if the configuration, for example the IP configuration, already exists.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the network
  hosts: managed-node-01.example.com
  tasks:
    - name: Ethernet connection profile with static IP address settings
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          - name: enp7s0
            type: ethernet
            autoconnect: yes
            ip:
              address:
                - 192.0.2.1/24
                - 2001:db8:1::1/64
              gateway4: 192.0.2.254
              gateway6: 2001:db8:1::fffe
              dns:
                - 192.0.2.200
                - 2001:db8:1::ffbb
              dns_search:
                - example.com
              route:
                - network: 198.51.100.0
                  prefix: 24
                  gateway: 192.0.2.10
                - network: '2001:db8:2::'
                  prefix: 64
                  gateway: 2001:db8:1::10
            state: up
    Copy to Clipboard Toggle word wrap

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. Display the IPv4 routes: 

    # ansible managed-node-01.example.com -m command -a 'ip -4 route'
managed-node-01.example.com | CHANGED | rc=0 >>
...
198.51.100.0/24 via 192.0.2.10 dev enp7s0
    Copy to Clipboard Toggle word wrap

  2. Display the IPv6 routes: 

    # ansible managed-node-01.example.com -m command -a 'ip -6 route'
managed-node-01.example.com | CHANGED | rc=0 >>
...
2001:db8:2::/64 via 2001:db8:1::10 dev enp7s0 metric 1024 pref medium
    Copy to Clipboard Toggle word wrap

You can use policy-based routing to configure a different default gateway for traffic from certain subnets. By using the network RHEL system role, you can automate the creation of the connection profiles, including routing tables and rules.

For example, you can configure RHEL as a router that, by default, routes all traffic to internet provider A using the default route. However, traffic received from the internal workstations subnet is routed to provider B. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

This procedure assumes the following network topology:

policy based routing

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The managed nodes use NetworkManager and the firewalld service.

  • The managed nodes you want to configure has four network interfaces:

    • The enp7s0 interface is connected to the network of provider A. The gateway IP in the provider’s network is 198.51.100.2, and the network uses a /30 network mask.
    • The enp1s0 interface is connected to the network of provider B. The gateway IP in the provider’s network is 192.0.2.2, and the network uses a /30 network mask.
    • The enp8s0 interface is connected to the 10.0.0.0/24 subnet with internal workstations.
    • The enp9s0 interface is connected to the 203.0.113.0/24 subnet with the company’s servers.
  • Hosts in the internal workstations subnet use 10.0.0.1 as the default gateway. In the procedure, you assign this IP address to the enp8s0 network interface of the router.
  • Hosts in the server subnet use 203.0.113.1 as the default gateway. In the procedure, you assign this IP address to the enp9s0 network interface of the router.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configuring policy-based routing
  hosts: managed-node-01.example.com
  tasks:
    - name: Routing traffic from a specific subnet to a different default gateway
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          - name: Provider-A
            interface_name: enp7s0
            type: ethernet
            autoconnect: True
            ip:
              address:
                - 198.51.100.1/30
              gateway4: 198.51.100.2
              dns:
                - 198.51.100.200
            state: up
            zone: external

          - name: Provider-B
            interface_name: enp1s0
            type: ethernet
            autoconnect: True
            ip:
              address:
                - 192.0.2.1/30
              route:
                - network: 0.0.0.0
                  prefix: 0
                  gateway: 192.0.2.2
                  table: 5000
            state: up
            zone: external

          - name: Internal-Workstations
            interface_name: enp8s0
            type: ethernet
            autoconnect: True
            ip:
              address:
                - 10.0.0.1/24
              route:
                - network: 10.0.0.0
                  prefix: 24
                  table: 5000
              routing_rule:
                - priority: 5
                  from: 10.0.0.0/24
                  table: 5000
            state: up
            zone: trusted

          - name: Servers
            interface_name: enp9s0
            type: ethernet
            autoconnect: True
            ip:
              address:
                - 203.0.113.1/24
            state: up
            zone: trusted
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    table: <value>
    Assigns the route from the same list entry as the table variable to the specified routing table.
    routing_rule: <list>
    Defines the priority of the specified routing rule and from a connection profile to which routing table the rule is assigned.
    zone: <zone_name>
    Assigns the network interface from a connection profile to the specified firewalld zone.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. On a RHEL host in the internal workstation subnet:

    1. Install the traceroute package: 

      # dnf install traceroute
      Copy to Clipboard Toggle word wrap

    2. Use the traceroute utility to display the route to a host on the internet: 

      # traceroute redhat.com
traceroute to redhat.com (209.132.183.105), 30 hops max, 60 byte packets
 1  10.0.0.1 (10.0.0.1)     0.337 ms  0.260 ms  0.223 ms
 2  192.0.2.2 (192.0.2.2)   0.884 ms  1.066 ms  1.248 ms
 ...
      Copy to Clipboard Toggle word wrap

      The output of the command displays that the router sends packets over 192.0.2.1, which is the network of provider B.

  2. On a RHEL host in the server subnet:

    1. Install the traceroute package: 

      # dnf install traceroute
      Copy to Clipboard Toggle word wrap

    2. Use the traceroute utility to display the route to a host on the internet: 

      # traceroute redhat.com
traceroute to redhat.com (209.132.183.105), 30 hops max, 60 byte packets
 1  203.0.113.1 (203.0.113.1)    2.179 ms  2.073 ms  1.944 ms
 2  198.51.100.2 (198.51.100.2)  1.868 ms  1.798 ms  1.549 ms
 ...
      Copy to Clipboard Toggle word wrap

      The output of the command displays that the router sends packets over 198.51.100.2, which is the network of provider A.

  3. On the RHEL router that you configured using the RHEL system role:

    1. Display the rule list: 

      # ip rule list
0:      from all lookup local
5:    from 10.0.0.0/24 lookup 5000
32766:  from all lookup main
32767:  from all lookup default
      Copy to Clipboard Toggle word wrap

      By default, RHEL contains rules for the tables local, main, and default.

    2. Display the routes in table 5000: 

      # ip route list table 5000
0.0.0.0/0 via 192.0.2.2 dev enp1s0 proto static metric 100
10.0.0.0/24 dev enp8s0 proto static scope link src 192.0.2.1 metric 102
      Copy to Clipboard Toggle word wrap

    3. Display the interfaces and firewall zones: 

      # firewall-cmd --get-active-zones
external
  interfaces: enp1s0 enp7s0
trusted
  interfaces: enp8s0 enp9s0
      Copy to Clipboard Toggle word wrap

    4. Verify that the external zone has masquerading enabled: 

      # firewall-cmd --info-zone=external
external (active)
  target: default
  icmp-block-inversion: no
  interfaces: enp1s0 enp7s0
  sources:
  services: ssh
  ports:
  protocols:
  masquerade: yes
  ...
      Copy to Clipboard Toggle word wrap

You can use the network RHEL system role to automate configuring TCP offload engine (TOE) to offload processing certain operations to the network controller. TOE improves the network throughput.

Warning

You cannot use the network RHEL system role to update only specific values in an existing connection profile. The role ensures that a connection profile exactly matches the settings in a playbook. If a connection profile with the same name already exists, the role applies the settings from the playbook and resets all other settings in the profile to their defaults. To prevent resetting values, always specify the whole configuration of the network connection profile in the playbook, including the settings that you do not want to change.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the network
  hosts: managed-node-01.example.com
  tasks:
    - name: Ethernet connection profile with dynamic IP address settings and offload features
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          - name: enp1s0
            type: ethernet
            autoconnect: yes
            ip:
              dhcp4: yes
              auto6: yes
            ethtool:
              features:
                gro: no
                gso: yes
                tx_sctp_segmentation: no
            state: up
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    gro: no
    Disables Generic receive offload (GRO).
    gso: yes
    Enables Generic segmentation offload (GSO).
    tx_sctp_segmentation: no
    Disables TX stream control transmission protocol (SCTP) segmentation.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Query the Ansible facts of the managed node and verify the offload settings: 

    # ansible managed-node-01.example.com -m ansible.builtin.setup
...
        "ansible_enp1s0": {
            "active": true,
            "device": "enp1s0",
	    "features": {
	        ...
		"rx_gro_hw": "off,
	        ...
		"tx_gso_list": "on,
	        ...
		"tx_sctp_segmentation": "off",
		...
            }
...
    Copy to Clipboard Toggle word wrap

Interrupt coalescing collects network packets and generates a single interrupt for multiple packets. This reduces interrupt load and maximizes throughput. You can automate the configuration of these settings in the NetworkManager connection profile by using the network RHEL system role.

Warning

You cannot use the network RHEL system role to update only specific values in an existing connection profile. The role ensures that a connection profile exactly matches the settings in a playbook. If a connection profile with the same name already exists, the role applies the settings from the playbook and resets all other settings in the profile to their defaults. To prevent resetting values, always specify the whole configuration of the network connection profile in the playbook, including the settings that you do not want to change.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the network
  hosts: managed-node-01.example.com
  tasks:
    - name: Ethernet connection profile with dynamic IP address settings and coalesce settings
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          - name: enp1s0
            type: ethernet
            autoconnect: yes
            ip:
              dhcp4: yes
              auto6: yes
            ethtool:
              coalesce:
                rx_frames: 128
                tx_frames: 128
            state: up
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    rx_frames: <value>
    Sets the number of RX frames.
    gso: <value>
    Sets the number of TX frames.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Display the current offload features of the network device: 

    # ansible managed-node-01.example.com -m command -a 'ethtool -c enp1s0'
managed-node-01.example.com | CHANGED | rc=0 >>
...
rx-frames:	128
...
tx-frames:	128
...
    Copy to Clipboard Toggle word wrap

Increase the size of an Ethernet device’s ring buffers if the packet drop rate causes applications to report a loss of data, timeouts, or other issues.

Ring buffers are circular buffers where an overflow overwrites existing data. The network card assigns a transmit (TX) and receive (RX) ring buffer. Receive ring buffers are shared between the device driver and the network interface controller (NIC). Data can move from NIC to the kernel through either hardware interrupts or software interrupts, also called SoftIRQs.

The kernel uses the RX ring buffer to store incoming packets until the device driver can process them. The device driver drains the RX ring, typically by using SoftIRQs, which puts the incoming packets into a kernel data structure called an sk_buff or skb to begin its journey through the kernel and up to the application that owns the relevant socket.

The kernel uses the TX ring buffer to hold outgoing packets which should be sent to the network. These ring buffers reside at the bottom of the stack and are a crucial point at which packet drop can occur, which in turn will adversely affect network performance.

You configure ring buffer settings in the NetworkManager connection profiles. By using Ansible and the network RHEL system role, you can automate this process and remotely configure connection profiles on the hosts defined in a playbook.

Warning

You cannot use the network RHEL system role to update only specific values in an existing connection profile. The role ensures that a connection profile exactly matches the settings in a playbook. If a connection profile with the same name already exists, the role applies the settings from the playbook and resets all other settings in the profile to their defaults. To prevent resetting values, always specify the whole configuration of the network connection profile in the playbook, including the settings that you do not want to change.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • You know the maximum ring buffer sizes that the device supports.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the network
  hosts: managed-node-01.example.com
  tasks:
    - name: Ethernet connection profile with dynamic IP address setting and increased ring buffer sizes
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          - name: enp1s0
            type: ethernet
            autoconnect: yes
            ip:
              dhcp4: yes
              auto6: yes
            ethtool:
              ring:
                rx: 4096
                tx: 4096
            state: up
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    rx: <value>
    Sets the maximum number of received ring buffer entries.
    tx: <value>
    Sets the maximum number of transmitted ring buffer entries.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Display the maximum ring buffer sizes: 

    # ansible managed-node-01.example.com -m command -a 'ethtool -g enp1s0'
managed-node-01.example.com | CHANGED | rc=0 >>
...
Current hardware settings:
RX:             4096
RX Mini:        0
RX Jumbo:       0
TX:             4096
    Copy to Clipboard Toggle word wrap

To configure IP over InfiniBand (IPoIB), create a NetworkManager connection profile. You can automate this process by using the network RHEL system role and remotely configure connection profiles on hosts defined in a playbook.

You can use the network RHEL system role to configure IPoIB and, if a connection profile for the InfiniBand’s parent device does not exist, the role can create it as well.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • An InfiniBand device named mlx4_ib0 is installed in the managed nodes.
  • The managed nodes use NetworkManager to configure the network.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the network
  hosts: managed-node-01.example.com
  tasks:
    - name: IPoIB connection profile with static IP address settings
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.network
      vars:
        network_connections:
          # InfiniBand connection mlx4_ib0
          - name: mlx4_ib0
            interface_name: mlx4_ib0
            type: infiniband

          # IPoIB device mlx4_ib0.8002 on top of mlx4_ib0
          - name: mlx4_ib0.8002
            type: infiniband
            autoconnect: yes
            infiniband:
              p_key: 0x8002
              transport_mode: datagram
            parent: mlx4_ib0
            ip:
              address:
                - 192.0.2.1/24
                - 2001:db8:1::1/64
            state: up
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    type: <profile_type>
    Sets the type of the profile to create. The example playbook creates two connection profiles: One for the InfiniBand connection and one for the IPoIB device.
    parent: <parent_device>
    Sets the parent device of the IPoIB connection profile.
    p_key: <value>
    Sets the InfiniBand partition key. If you set this variable, do not set interface_name on the IPoIB device.
    transport_mode: <mode>
    Sets the IPoIB connection operation mode. You can set this variable to datagram (default) or connected.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.network/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. Display the IP settings of the mlx4_ib0.8002 device: 

    # ansible managed-node-01.example.com -m command -a 'ip address show mlx4_ib0.8002'
managed-node-01.example.com | CHANGED | rc=0 >>
...
inet 192.0.2.1/24 brd 192.0.2.255 scope global noprefixroute ib0.8002
   valid_lft forever preferred_lft forever
inet6 2001:db8:1::1/64 scope link tentative noprefixroute
   valid_lft forever preferred_lft forever
    Copy to Clipboard Toggle word wrap

  2. Display the partition key (P_Key) of the mlx4_ib0.8002 device: 

    # ansible managed-node-01.example.com -m command -a 'cat /sys/class/net/mlx4_ib0.8002/pkey'
managed-node-01.example.com | CHANGED | rc=0 >>
0x8002
    Copy to Clipboard Toggle word wrap

  3. Display the mode of the mlx4_ib0.8002 device: 

    # ansible managed-node-01.example.com -m command -a 'cat /sys/class/net/mlx4_ib0.8002/mode'
managed-node-01.example.com | CHANGED | rc=0 >>
datagram
    Copy to Clipboard Toggle word wrap

The network RHEL system role supports state configurations in playbooks to configure the devices. For this, use the network_state variable followed by the state configurations.

Benefits of using the network_state variable in a playbook:

  • Using the declarative method with the state configurations, you can configure interfaces, and the NetworkManager creates a profile for these interfaces in the background.
  • With the network_state variable, you can specify the options that you require to change, and all the other options will remain the same as they are. However, with the network_connections variable, you must specify all settings to change the network connection profile.
Important

You can set only Nmstate YAML instructions in network_state. These instructions differ from the variables you can set in network_connections.

For example, to create an Ethernet connection with dynamic IP address settings, use the following vars block in your playbook:

Expand

Playbook with state configurations

Regular playbook 

vars:
  network_state:
    interfaces:
    - name: enp7s0
      type: ethernet
      state: up
      ipv4:
        enabled: true
        auto-dns: true
        auto-gateway: true
        auto-routes: true
        dhcp: true
      ipv6:
        enabled: true
        auto-dns: true
        auto-gateway: true
        auto-routes: true
        autoconf: true
        dhcp: true
Copy to Clipboard Toggle word wrap 
vars:
  network_connections:
    - name: enp7s0
      interface_name: enp7s0
      type: ethernet
      autoconnect: yes
      ip:
        dhcp4: yes
        auto6: yes
      state: up
Copy to Clipboard Toggle word wrap

For example, to only change the connection status of dynamic IP address settings that you created as above, use the following vars block in your playbook:

Expand

Playbook with state configurations

Regular playbook 

vars:
  network_state:
    interfaces:
    - name: enp7s0
      type: ethernet
      state: down
Copy to Clipboard Toggle word wrap 
vars:
  network_connections:
    - name: enp7s0
      interface_name: enp7s0
      type: ethernet
      autoconnect: yes
      ip:
        dhcp4: yes
        auto6: yes
      state: down
Copy to Clipboard Toggle word wrap

With the podman RHEL system role, you can manage Podman configuration, containers, and systemd services that run Podman containers.

You can use the podman RHEL system role to create rootless containers with bind mount by running an Ansible playbook and with that, manage your application configuration.

The example Ansible playbook starts two Kubernetes pods: one for a database and another for a web application. The database pod configuration is specified in the playbook, while the web application pod is defined in an external YAML file.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The user and group webapp exist, and must be listed in the /etc/subuid and /etc/subgid files on the host.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    - name: Configure Podman
  hosts: managed-node-01.example.com
  tasks:
    - name: Create a web application and a database
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.podman
      vars:
        podman_create_host_directories: true
        podman_firewall:
          - port: 8080-8081/tcp
            state: enabled
          - port: 12340/tcp
            state: enabled
        podman_selinux_ports:
          - ports: 8080-8081
            setype: http_port_t
        podman_kube_specs:
          - state: started
            run_as_user: dbuser
            run_as_group: dbgroup
            kube_file_content:
              apiVersion: v1
              kind: Pod
              metadata:
                name: db
              spec:
                containers:
                  - name: db
                    image:  quay.io/linux-system-roles/mysql:5.6
                    ports:
                      - containerPort: 1234
                        hostPort: 12340
                    volumeMounts:
                      - mountPath: /var/lib/db:Z
                        name: db
                volumes:
                  - name: db
                    hostPath:
                      path: /var/lib/db
          - state: started
            run_as_user: webapp
            run_as_group: webapp
            kube_file_src: /path/to/webapp.yml
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    run_as_user and run_as_group
    Specify that containers are rootless.
    kube_file_content

    Contains a Kubernetes YAML file defining the first container named db. You can generate the Kubernetes YAML file by using the podman kube generate command.

    • The db container is based on the quay.io/db/db:stable container image.
    • The db bind mount maps the /var/lib/db directory on the host to the /var/lib/db directory in the container. The Z flag labels the content with a private unshared label, therefore, only the db container can access the content.
    kube_file_src: <path>
    Defines the second container. The content of the /path/to/webapp.yml file on the controller node will be copied to the kube_file field on the managed node.
    volumes: <list>
    A YAML list to define the source of the data to provide in one or more containers. For example, a local disk on the host (hostPath) or other disk device.
    volumeMounts: <list>
    A YAML list to define the destination where the individual container will mount a given volume.
    podman_create_host_directories: true
    Creates the directory on the host. This instructs the role to check the kube specification for hostPath volumes and create those directories on the host. If you need more control over the ownership and permissions, use podman_host_directories.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.podman/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the podman RHEL system role to create a rootful container with a Podman volume by running an Ansible playbook and with that, manage your application configuration.

The example Ansible playbook deploys a Kubernetes pod named ubi8-httpd running an HTTP server container from the registry.access.redhat.com/ubi8/httpd-24 image. The container’s web content is mounted from a persistent volume named ubi8-html-volume. By default, the podman role creates rootful containers.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    - name: Configure Podman
  hosts: managed-node-01.example.com
  tasks:
    - name: Start Apache server on port 8080
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.podman
  vars:
    podman_firewall:
      - port: 8080/tcp
        state: enabled
    podman_kube_specs:
      - state: started
        kube_file_content:
          apiVersion: v1
          kind: Pod
          metadata:
            name: ubi8-httpd
          spec:
            containers:
              - name: ubi8-httpd
                image: registry.access.redhat.com/ubi8/httpd-24
                ports:
                  - containerPort: 8080
                    hostPort: 8080
                volumeMounts:
                  - mountPath: /var/www/html:Z
                    name: ubi8-html
            volumes:
              - name: ubi8-html
                persistentVolumeClaim:
                  claimName: ubi8-html-volume
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    kube_file_content

    Contains a Kubernetes YAML file defining the first container named db. You can generate the Kubernetes YAML file by using the podman kube generate command.

    • The ubi8-httpd container is based on the registry.access.redhat.com/ubi8/httpd-24 container image.
    • The ubi8-html-volume maps the /var/www/html directory on the host to the container. The Z flag labels the content with a private unshared label, therefore, only the ubi8-httpd container can access the content.
    • The pod mounts the existing persistent volume named ubi8-html-volume with the mount path /var/www/html.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.podman/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the podman RHEL system role to create a Quadlet application with secrets by running an Ansible playbook.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The certificate and the corresponding private key that the web server in the container should use are stored in the ~/certificate.pem and ~/key.pem files.

Procedure

  1. Display the contents of the certificate and private key files: 

    $ cat ~/certificate.pem
-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----

$ cat ~/key.pem
-----BEGIN PRIVATE KEY-----
...
-----END PRIVATE KEY-----
    Copy to Clipboard Toggle word wrap

    You require this information in a later step.

  2. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      root_password: <root_password>
certificate: |-
  -----BEGIN CERTIFICATE-----
  ...
  -----END CERTIFICATE-----
key: |-
  -----BEGIN PRIVATE KEY-----
  ...
  -----END PRIVATE KEY-----
      Copy to Clipboard Toggle word wrap

      Ensure that all lines in the certificate and key variables start with two spaces.

    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  3. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    - name: Deploy a wordpress CMS with MySQL database
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
  - name: Create and run the container
    ansible.builtin.include_role:
      name: redhat.rhel_system_roles.podman
    vars:
      podman_create_host_directories: true
      podman_activate_systemd_unit: false
      podman_quadlet_specs:
        - name: quadlet-demo
          type: network
          file_content: |
            [Network]
            Subnet=192.168.30.0/24
            Gateway=192.168.30.1
            Label=app=wordpress
        - file_src: quadlet-demo-mysql.volume
        - template_src: quadlet-demo-mysql.container.j2
        - file_src: envoy-proxy-configmap.yml
        - file_src: quadlet-demo.yml
        - file_src: quadlet-demo.kube
          activate_systemd_unit: true
      podman_firewall:
        - port: 8000/tcp
          state: enabled
        - port: 9000/tcp
          state: enabled
      podman_secrets:
        - name: mysql-root-password-container
          state: present
          skip_existing: true
          data: "{{ root_password }}"
        - name: mysql-root-password-kube
          state: present
          skip_existing: true
          data: |
            apiVersion: v1
            data:
              password: "{{ root_password | b64encode }}"
            kind: Secret
            metadata:
              name: mysql-root-password-kube
        - name: envoy-certificates
          state: present
          skip_existing: true
          data: |
            apiVersion: v1
            data:
              certificate.key: {{ key | b64encode }}
              certificate.pem: {{ certificate | b64encode }}
            kind: Secret
            metadata:
              name: envoy-certificates
    Copy to Clipboard Toggle word wrap

    The procedure creates a WordPress content management system paired with a MySQL database. The podman_quadlet_specs role variable defines a set of configurations for the Quadlet, which refers to a group of containers or services that work together in a certain way. It includes the following specifications:

    • The Wordpress network is defined by the quadlet-demo network unit.
    • The volume configuration for MySQL container is defined by the file_src: quadlet-demo-mysql.volume field.
    • The template_src: quadlet-demo-mysql.container.j2 field is used to generate a configuration for the MySQL container.
    • Two YAML files follow: file_src: envoy-proxy-configmap.yml and file_src: quadlet-demo.yml. Note that .yml is not a valid Quadlet unit type, therefore these files will just be copied and not processed as a Quadlet specification.
    • The Wordpress and envoy proxy containers and configuration are defined by the file_src: quadlet-demo.kube field. The kube unit refers to the previous YAML files in the [Kube] section as Yaml=quadlet-demo.yml and ConfigMap=envoy-proxy-configmap.yml.

  4. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  5. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the postfix RHEL system role to consistently manage configurations of the Postfix mail transfer agent (MTA) in an automated fashion.

Deploying Postfix configurations are helpful when you need for example:

  • Stable mail server: enables system administrators to configure a fast and scalable server for sending and receiving emails.
  • Secure communication: supports features such as TLS encryption, authentication, domain blacklisting, and more, to ensure safe email transmission.
  • Improved email management and routing: implements filters and rules so that you have control over your email traffic.
Important

The postfix_conf dictionary holds key-value pairs of the supported Postfix configuration parameters. Those keys that Postfix does not recognize as supported are ignored. The postfix RHEL system role directly passes the key-value pairs that you provide to the postfix_conf dictionary without verifying their syntax or limiting them. Therefore, the role is especially useful to those familiar with Postfix, and who know how to configure it.

You can use the postfix RHEL system role to automate configuring Postfix as a null client for sending outgoing emails.

A null client is a special configuration, where the Postfix server is set up only to send outgoing emails, but not receive any incoming emails. Such a setup is widely used in scenarios where you need to send notifications, alerts, or logs; but receiving or managing emails is not needed.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage Postfix
  hosts: managed-node-01.example.com
  tasks:
    - name: Install postfix
      ansible.builtin.package:
        name: postfix
        state: present

    - name: Configure null client for only sending outgoing emails
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.postfix
      vars:
        postfix_conf:
          myhostname: server.example.com
          myorigin: "$mydomain"
          relayhost: smtp.example.com
          inet_interfaces: loopback-only
          mydestination: ""
          relay_domains: "{{ lookup('ansible.builtin.pipe', 'postconf -h default_database_type') }}:/etc/postfix/relay_domains"
        postfix_files:
          - name: relay_domains
            postmap: true
            content: |
              example.com OK
              example.net OK
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    myhostname: <server.example.com>
    The internet hostname of this mail system. Defaults to the fully-qualified domain name (FQDN).
    myorigin: $mydomain
    The domain name that locally-posted mail appears to come from and that locally posted mail is delivered to. Defaults to $myhostname.
    relayhost: <smtp.example.com>
    The next-hop destination(s) for non-local mail, overrides non-local domains in recipient addresses. Defaults to an empty field.
    inet_interfaces: loopback-only
    Defines which network interfaces the Postfix server listens on for incoming email connections. It controls whether and how the Postfix server accepts email from the network.
    mydestination
    Defines which domains and hostnames are considered local.
    relay_domains: "hash:/etc/postfix/relay_domains"
    Specifies the domains that Postfix can forward emails to when it is acting as a relay server (SMTP relay). In this case the domains will be generated by the postfix_files variable. On RHEL 10, you have to use relay_domains: "lmdb:/etc/postfix/relay_domains".
    postfix_files
    Defines a list of files that will be placed in the /etc/postfix/ directory. Those files can be converted into Postfix Lookup Tables if needed. In this case postfix_files generates domain names for the SMTP relay.

    For details about the role variables and the Postfix configuration parameters used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.postfix/README.md file and the postconf(5) manual page on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the postgresql RHEL system role to automate the installation and management of the PostgreSQL database server. By default, this role also optimizes PostgreSQL by automatically configuring performance-related settings in the PostgreSQL service configuration files.

You can configure PostgreSQL with TLS encryption using the postgresql RHEL system role to automate secure database setup with existing certificates and private keys.

Note

The postgresql role cannot open ports in the firewalld service. To allow remote access to the PostgreSQL server, add a task that uses the firewall RHEL system role to your playbook.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.

  • Both the private key of the managed node and the certificate are stored on the control node in the following files:

    • Private key: ~/<FQDN_of_the_managed_node>.key
    • Certificate: ~/<FQDN_of_the_managed_node>.crt

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Installing and configuring PostgreSQL
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Create directory for TLS certificate and key
      ansible.builtin.file:
        path: /etc/postgresql/
        state: directory
        mode: 755

    - name: Copy CA certificate
      ansible.builtin.copy:
        src: "~/{{ inventory_hostname }}.crt"
        dest: "/etc/postgresql/server.crt"

    - name: Copy private key
      ansible.builtin.copy:
        src: "~/{{ inventory_hostname }}.key"
        dest: "/etc/postgresql/server.key"
        mode: 0600

    - name: PostgreSQL with an existing private key and certificate
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.postgresql
      vars:
        postgresql_version: "16"
        postgresql_password: "{{ pwd }}"
        postgresql_ssl_enable: true
        postgresql_cert_name: "/etc/postgresql/server"
        postgresql_server_conf:
          listen_addresses: "'*'"
          password_encryption: scram-sha-256
        postgresql_pg_hba_conf:
          - type: local
            database: all
            user: all
            auth_method: scram-sha-256
          - type: hostssl
            database: all
            user: all
            address: '127.0.0.1/32'
            auth_method: scram-sha-256
          - type: hostssl
            database: all
            user: all
            address: '::1/128'
            auth_method: scram-sha-256
          - type: hostssl
            database: all
            user: all
            address: '192.0.2.0/24'
            auth_method: scram-sha-256


    - name: Open the PostgresQL port in firewalld
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.firewall
      vars:
        firewall:
          - service: postgresql
            state: enabled
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    postgresql_version: <version>

    Sets the version of PostgreSQL to install. The version you can set depends on the PostgreSQL versions that are available in Red Hat Enterprise Linux running on the managed node.

    You cannot upgrade or downgrade PostgreSQL by changing the postgresql_version variable and running the playbook again.

    postgresql_password: <password>

    Sets the password of the postgres database superuser.

    You cannot change the password by changing the postgresql_password variable and running the playbook again.

    postgresql_cert_name: <private_key_and_certificate_file>

    Defines the path and base name of both the certificate and private key on the managed node without .crt and key suffixes. During the PostgreSQL configuration, the role creates symbolic links in the /var/lib/pgsql/data/ directory that refer to these files.

    The certificate and private key must exist locally on the managed node. You can use tasks with the ansible.builtin.copy module to transfer the files from the control node to the managed node, as shown in the playbook.

    postgresql_server_conf: <list_of_settings>

    Defines postgresql.conf settings the role should set. The role adds these settings to the /etc/postgresql/system-roles.conf file and includes this file at the end of /var/lib/pgsql/data/postgresql.conf. Consequently, settings from the postgresql_server_conf variable override settings in /var/lib/pgsql/data/postgresql.conf.

    Re-running the playbook with different settings in postgresql_server_conf overwrites the /etc/postgresql/system-roles.conf file with the new settings.

    postgresql_pg_hba_conf: <list_of_authentication_entries>

    Configures client authentication entries in the /var/lib/pgsql/data/pg_hba.conf file. For details, see see the PostgreSQL documentation.

    The example allows the following connections to PostgreSQL:

    • Unencrypted connections by using local UNIX domain sockets.
    • TLS-encrypted connections to the IPv4 and IPv6 localhost addresses.
    • TLS-encrypted connections from the 192.0.2.0/24 subnet. Note that access from remote addresses is only possible if you also configure the listen_addresses setting in the postgresql_server_conf variable appropriately.

    Re-running the playbook with different settings in postgresql_pg_hba_conf overwrites the /var/lib/pgsql/data/pg_hba.conf file with the new settings.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.postgresql/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Use the postgres super user to connect to a PostgreSQL server and execute the \conninfo meta command: 

    # psql "postgresql://postgres@managed-node-01.example.com:5432" -c '\conninfo'
Password for user postgres:
You are connected to database "postgres" as user "postgres" on host "192.0.2.1" at port "5432".
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, compression: off)
    Copy to Clipboard Toggle word wrap

    If the output displays a TLS protocol version and cipher details, the connection works and TLS encryption is enabled.

You can configure PostgreSQL with TLS encryption using the postgresql RHEL system role to automate secure database setup with certificates issued from Identity Management (IdM) and managed by the certmonger service.

Note

The postgresql role cannot open ports in the firewalld service. To allow remote access to the PostgreSQL server, add a task to your playbook that uses the firewall RHEL system role.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • You enrolled the managed node in an IdM domain.

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Installing and configuring PostgreSQL
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: PostgreSQL with certificates issued by IdM
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.postgresql
      vars:
        postgresql_version: "16"
        postgresql_password: "{{ pwd }}"
        postgresql_ssl_enable: true
        postgresql_certificates:
          - name: postgresql_cert
            dns: "{{ inventory_hostname }}"
            ca: ipa
            principal: "postgresql/{{ inventory_hostname }}@EXAMPLE.COM"
        postgresql_server_conf:
          listen_addresses: "'*'"
          password_encryption: scram-sha-256
        postgresql_pg_hba_conf:
          - type: local
            database: all
            user: all
            auth_method: scram-sha-256
          - type: hostssl
            database: all
            user: all
            address: '127.0.0.1/32'
            auth_method: scram-sha-256
          - type: hostssl
            database: all
            user: all
            address: '::1/128'
            auth_method: scram-sha-256
          - type: hostssl
            database: all
            user: all
            address: '192.0.2.0/24'
            auth_method: scram-sha-256


    - name: Open the PostgresQL port in firewalld
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.firewall
      vars:
        firewall:
          - service: postgresql
            state: enabled
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    postgresql_version: <version>

    Sets the version of PostgreSQL to install. The version you can set depends on the PostgreSQL versions that are available in Red Hat Enterprise Linux running on the managed node.

    You cannot upgrade or downgrade PostgreSQL by changing the postgresql_version variable and running the playbook again.

    postgresql_password: <password>

    Sets the password of the postgres database superuser.

    You cannot change the password by changing the postgresql_password variable and running the playbook again.

    postgresql_certificates: <certificate_role_settings>
    A list of YAML dictionaries with settings for the certificate role.
    postgresql_server_conf: <list_of_settings>

    Defines postgresql.conf settings you want the role to set. The role adds these settings to the /etc/postgresql/system-roles.conf file and includes this file at the end of /var/lib/pgsql/data/postgresql.conf. Consequently, settings from the postgresql_server_conf variable override settings in /var/lib/pgsql/data/postgresql.conf.

    Re-running the playbook with different settings in postgresql_server_conf overwrites the /etc/postgresql/system-roles.conf file with the new settings.

    postgresql_pg_hba_conf: <list_of_authentication_entries>

    Configures client authentication entries in the /var/lib/pgsql/data/pg_hba.conf file. For details, see see the PostgreSQL documentation.

    The example allows the following connections to PostgreSQL:

    • Unencrypted connections by using local UNIX domain sockets.
    • TLS-encrypted connections to the IPv4 and IPv6 localhost addresses.
    • TLS-encrypted connections from the 192.0.2.0/24 subnet. Note that access from remote addresses is only possible if you also configure the listen_addresses setting in the postgresql_server_conf variable appropriately.

    Re-running the playbook with different settings in postgresql_pg_hba_conf overwrites the /var/lib/pgsql/data/pg_hba.conf file with the new settings.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.postgresql/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Use the postgres super user to connect to a PostgreSQL server and execute the \conninfo meta command: 

    # psql "postgresql://postgres@managed-node-01.example.com:5432" -c '\conninfo'
Password for user postgres:
You are connected to database "postgres" as user "postgres" on host "192.0.2.1" at port "5432".
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, compression: off)
    Copy to Clipboard Toggle word wrap

    If the output displays a TLS protocol version and cipher details, the connection works and TLS encryption is enabled.

The rhc RHEL system role enables administrators to automate the registration of multiple systems with Red Hat Subscription Management (RHSM) and Satellite servers. The role also supports Insights-related configuration and management tasks by using Ansible.

By default, when you register a system by using rhc, the system is connected to Red Hat Insights. Additionally, with rhc, you can:

  • Configure connections to Red Hat Insights
  • Enable and disable repositories
  • Configure the proxy to use for the connection
  • Configure Insights remediations and, auto updates
  • Set the release of the system
  • Configure Insights tags

You can register multiple systems at scale with Red Hat subscription management (RHSM) by using the rhc RHEL system role. By default, rhc connects the system to Red Hat Insights when you register it.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      activationKey: <activation_key>
organizationID: <organizationID>
username: <username>
password: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content:

    • To register by using an activation key and organization ID (recommended), use the following playbook: 

      ---
- name: Managing systems with the rhc RHEL system role
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Registering system using activation key and organization ID
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.rhc
      vars:
        rhc_auth:
          activation_keys:
            keys:
              - "{{ activationKey }}"
        rhc_organization: "{{ organizationID }}"
      Copy to Clipboard Toggle word wrap

      The settings specified in the example playbook include the following:

      rhc_auth: activation_keys
      The key activation_keys specifies that you want to register by using the activation keys.

    • To register by using a username and password, use the following playbook: 

      ---
- name: Managing systems with the rhc RHEL system role
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Registering system with username and password
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.rhc
      vars:
        rhc_auth:
          login:
            username: "{{ username }}"
            password: "{{ password }}"
      Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    rhc_auth: login
    The key login specifies that you want to register by using the username and password.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

When organizations use Satellite to manage systems, it is necessary to register the system through Satellite. You can remotely register your system with Satellite by using the rhc RHEL system role.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      activationKey: <activation_key>
organizationID: <organizationID>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing systems with the rhc RHEL system role
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Register to the custom registration server and CDN
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.rhc
      vars:
        rhc_auth:
          activation_keys:
            keys:
              - "{{ activationKey }}"
        rhc_organization: "{{ organizationID }}"
        rhc_server:
          hostname: example.com
            port: 443
            prefix: /rhsm
        rhc_baseurl: http://example.com/pulp/content
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    hostname: example.com
    A fully qualified domain name (FQDN) of the Satellite server for system registration and package management.
    port: 443
    Defines the network port used for communication with the Satellite server.
    prefix: /rhsm
    Specifies the URL path prefix for accessing resources on the Satellite server.
    rhc_baseurl: http://example.com/pulp/content
    Defines the prefix for content URLs. In a Satellite environment, the baseurl must be set to the same server where the system is registered. Refer to the hostname value to ensure the correct server is used.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

When you register a system by using the rhc RHEL system role, the role, by default, enables the connection to Red Hat Insights. You can disable Insights by using the rhc RHEL system role, if not required.

Red Hat Insights is a managed service in the Hybrid Cloud Console that uses predictive analytics, remediation capabilities, and deep domain expertise to simplify complex operational tasks.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing systems with the rhc RHEL system role
  hosts: managed-node-01.example.com
  tasks:
    - name: Disable Insights connection
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.rhc
      vars:
        rhc_insights:
          state: absent
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    rhc_insights absent|present
    Enables or disables system registration with Red Hat Insights for proactive analytics and recommendations.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Enabling repositories on a RHEL system is essential for accessing, installing, and updating software packages from verified sources. You can remotely enable or disable repositories on managed nodes by using rhc RHEL system role to ensure the system security, stability, and compatibility.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • You have details of the repositories which you want to enable or disable on the managed nodes.
  • You have registered the system.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing systems with the rhc RHEL system role
  hosts: managed-node-01.example.com
  tasks:
    - name: Enable repository
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.rhc
      vars:
        rhc_repositories:
          - name: "RepositoryName"
            state: enabled
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    name: RepositoryName
    Name of the repository that should be enabled.
    state: enabled|disabled
    Optional, enables or disables the repository. Default is enabled.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can lock your system to a specific RHEL release to maintain stability and prevent unintended updates in production environments.

To ensure system stability and compatibility, it is sometimes necessary to limit the RHEL system to use only repositories from a specific minor version rather than automatically upgrading to the latest available release. Locking the system to a particular minor version helps maintain consistency in production environments, which prevents unintended updates that might introduce compatibility issues.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • You know the RHEL version to which you want to lock the system. Note that you can only lock the system to the RHEL minor version that the managed node currently runs or a later minor version.
  • You have registered the system.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing systems with the rhc RHEL system role
  hosts: managed-node-01.example.com
  tasks:
    - name: Lock the system to a particular release
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.rhc
      vars:
        rhc_release: "8.6"
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    rhc_release: version
    The version of RHEL to set for the system, so the available content will be limited to that version.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

If your security restrictions allow access to the Internet only through a proxy server, you can specify the proxy settings of the rhc role when you register the system using rhc.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      username: <username>
password: <password>
proxy_username: <proxyusernme>
proxy_password: <proxypassword>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing systems with the rhc RHEL system role
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
  - name: Register to the Red Hat Customer Portal by using proxy
    ansible.builtin.include_role:
       name: redhat.rhel_system_roles.rhc
    vars:
      rhc_auth:
        login:
          username: "{{ username }}"
          password: "{{ password }}"
      rhc_proxy:
        hostname: proxy.example.com
        port: 3128
        username: "{{ proxy_username }}"
        password: "{{ proxy_password }}"
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    hostname: proxy.example.com
    A fully qualified domain name (FQDN) of the proxy server.
    port: 3128
    Defines the network port used for communication with the proxy server.
    username: proxy_username
    Specifies the username for authentication. This is required only if the proxy server requires authentication.
    password: proxy_password
    Specifies the password for authentication. This is required only if the proxy server requires authentication.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can enable or disable the automatic collection rule updates for Red Hat Insights by using the rhc RHEL system role. By default, when you connect your system to Red Hat Insights, this option is enabled. You can disable it by using rhc.

Warning

If you disable this feature, you risk using outdated rule definition files and not getting the most recent validation updates.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      username: <username>
password: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing systems with the rhc RHEL system role
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Enable Red Hat Insights autoupdates
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.rhc
      vars:
        rhc_auth:
          login:
            username: "{{ username }}"
            password: "{{ password }}"
        rhc_insights:
          autoupdate: true
          state: present
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    autoupdate: true|false
    Enables or disables the automatic collection rule updates for Red Hat Insights.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the rhc RHEL system role to configure Insights remediations on your systems. When you connect your system to Red Hat Insights, it is enabled by default.

You can use the rhc role to ensure your system is ready for remediation when connected directly to Red Hat. For more information about Red Hat Insights remediations, see Red Hat Insights Remediations Guide.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • You have Insights remediations enabled.
  • You have registered the system.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing systems with the rhc RHEL system role
  hosts: managed-node-01.example.com
  tasks:
    - name: Disable remediation
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.rhc
      vars:
        rhc_insights:
          remediation: absent
          state: present
    Copy to Clipboard Toggle word wrap

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the rhc RHEL system role to configure Red Hat Insights tags. With these tags you can efficiently filter and group systems based on attributes, such as their location. This simplifies automation and enhances security compliance across large infrastructures.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      username: <username>
password: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing systems with the rhc RHEL system role
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Creating tags
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.rhc
      vars:
        rhc_auth:
          login:
            username: "{{ username }}"
            password: "{{ password }}"
        rhc_insights:
          tags:
            group: group-name-value
            location: location-name-value
            description:
              - RHEL8
              - SAP
            sample_key: value
          state: present
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    group: group-name-value
    Specifies the system group for organizing and managing registered hosts.
    location: location-name-value
    Defines the location associated with the registered system.
    description
    Provides a brief summary or identifier for the registered system.
    state: present|absent

    Indicates the current status of the registered system.

    Note

    The content inside the tags is a YAML structure representing the tags desired by the administrator for the configured systems. The example provided here is for illustrative purposes only and is not exhaustive. Administrators can customize the YAML structure to include any additional keys and values as needed.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the rhc RHEL system role to unregister the system from the Red Hat subscription service if you no longer want to receive content from the registration server on a specific system, for example, system decommissioning, VM deletion, or when switching to a local content mirror.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing systems with the rhc RHEL system role
  hosts: managed-node-01.example.com
  tasks:
    - name: Unregister the system
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.rhc
      vars:
        rhc_state: absent
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    rhc_state: absent
    Specifies the system should be unregistered from the registration server, RHSM, or Satellite.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

With the Intelligent Platform Management Interface (IPMI) and the Redfish API, administrators can remotely manage hosts even if the operating system is not running. The rhel_mgmt Ansible collection provides modules that use IPMI and Redfish to perform certain remote operations.

You can set the boot device of a host by using the ipmi_boot module of the redhat.rhel_mgmt collection. This module uses the Intelligent Platform Management Interface (IPMI) to perform this operation.

Important

When you use this Ansible module, three hosts are involved: the control node, the managed node, and the host with the baseboard management controller (BMC) on which the actual IPMI operation is applied. The control node executes the playbook on the managed node. The managed host connects to the remote BMC to execute the IPMI operation. For example, if you set hosts: managed-node-01.example.com and name: server.example.com in the playbook, then managed-node-01.example.com changes the setting by using IPMI on server.example.com.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The ansible-collection-redhat-rhel_mgmt package is installed on the control node.
  • You have credentials to access the BMC, and these credentials have permissions to change settings.
  • The managed node can access the remote BMC over the network.

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      ipmi_usr: <username>
ipmi_pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Set the boot device by using IPMI
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Install python3-pyghmi prerequisite
      ansible.builtin.dnf:
        name: python3-pyghmi
        state: latest

    - name: Set the boot device to hd
      redhat.rhel_mgmt.ipmi_boot:
        name: <bmc_hostname_or_ip_address>
        port: <bmc_port_number>
        user: "{{ ipmi_usr }}"
        password: "{{ ipmi_pwd }}"
        bootdev: hd
        persistent: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    name: <bmc_hostname_or_ip_address>
    Defines the hostname or IP address of the BMC. This is the BMC of the host on which the managed node performs the action.
    port: <bmc_port_number>
    Sets the Remote Management Control Protocol (RMCP) port number. The default is 623.
    bootdev: <value>

    Sets the boot device. You can select one of the following values:

    • hd: Boots from the hard disk.
    • network: Boots from network.
    • optical: Boots from an optical drive, such as a DVD-ROM.
    • floppy: Boots from a floppy disk.
    • safe: Boots from hard drive in safe mode.
    • setup: Boots into the BIOS or UEFI.
    • default: Removes any IPMI-directed boot device request.
    persistent: <true|false>
    Configures whether the remote host uses the defined setting for all future boots or only for the next one. By default, this variable is set to false. Note that not all BMCs support setting the boot device persistently.

    For details about all variables used in the playbook, use the ansible-doc redhat.rhel_mgmt.ipmi_boot command on the control node to display the documentation of the module.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can set the hardware state by using the ipmi_power module of the redhat.rhel_mgmt collection. For example, you can ensure that a host is powered on or hard-reset it without involvement of the operating system.

The ipmi_power module uses the Intelligent Platform Management Interface (IPMI) to perform operations.

Important

When you use this Ansible module, three hosts are involved: the control node, the managed node, and the host with the baseboard management controller (BMC) on which the actual IPMI operation is applied. The control node executes the playbook on the managed node. The managed host connects to the remote BMC to execute the IPMI operation. For example, if you set hosts: managed-node-01.example.com and name: server.example.com in the playbook, then managed-node-01.example.com changes the setting by using IPMI on server.example.com.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The ansible-collection-redhat-rhel_mgmt package is installed on the control node.
  • You have credentials to access the BMC, and these credentials have permissions to change settings.
  • The managed node can access the remote BMC over the network.

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      ipmi_usr: <username>
ipmi_pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure the system state by using IPMI
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Install python3-pyghmi prerequisite
      ansible.builtin.dnf:
        name: python3-pyghmi
        state: latest

    - name: Ensure a machine is powered on
      redhat.rhel_mgmt.ipmi_power:
        name: <bmc_hostname_or_ip_address>
        port: <bmc_port_number>
        user: "{{ ipmi_usr }}"
        password: "{{ ipmi_pwd }}"
        state: on
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    name: <bmc_hostname_or_ip_address>
    Defines the hostname or IP address of the BMC. This is the BMC of the host on which the managed node performs the action.
    port: <bmc_port_number>
    Sets the Remote Management Control Protocol (RMCP) port number. The default is 623.
    state: <value>

    Sets the state which the device should be in. You can select one of the following values:

    • on: Powers on the system.
    • off: Powers off the system without notifying the operating system.
    • shutdown: Requests a shutdown from the operating system.
    • reset: Performs a hard reset.
    • boot: Powers on the system if it was switched off, or resets the system if it was switched off.

    For details about all variables used in the playbook, use the ansible-doc redhat.rhel_mgmt.ipmi_power command on the control node to display the documentation of the module.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can send commands to the Redfish API to remotely manage out-of-band (OOB) controllers by using the redfish_command module of the redhat.rhel_mgmt collection. With this module, you can perform a large number of management operations.

For example, you can perform the following operations:

  • Performing power management actions
  • Managing virtual media
  • Managing users of the OOB controller
  • Updating the firmware
Important

When you use this Ansible module, three hosts are involved: the control node, the managed node, and the host with the OOB controller on which the actual operation is performed. The control node executes the playbook on the managed node, and the managed host connects to the remote OOB controller by using the Redfish API to execute the operation. For example, if you set hosts: managed-node-01.example.com and baseuri: server.example.com in the playbook, then managed-node-01.example.com executes the operation on server.example.com.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The ansible-collection-redhat-rhel_mgmt package is installed on the control node.
  • You have credentials to access the OOB controller, and these credentials have permissions to change settings.
  • The managed node can access the remote OOB controller over the network.

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      redfish_usr: <username>
redfish_pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Send commands to OOB controller by using the Redfish API
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Power on the system
      redhat.rhel_mgmt.redfish_command:
        baseuri: <uri>
        username: "{{ redfish_usr }}"
        password: "{{ redfish_pwd }}"
        category: Systems
        command: PowerOn
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    baseuri: <uri>
    Defines the URI of the OOB controller. This is the OOB controller of the host on which the managed node performs the action.
    category: <value>

    Sets the category of the command to execute. The following categories are available:

    • Accounts: Manages user accounts of the OOB controller.
    • Chassis: Manages chassis-related settings.
    • Manager: Provides access to Redfish services.
    • Session: Manages Redfish login sessions.
    • Systems (default): Manages machine-related settings.
    • Update: Manages firmware update-related actions.
    command: <command>
    Sets the command to execute. Depending on the command, it can be necessary to set additional variables.

    For details about all variables used in the playbook, use the ansible-doc redhat.rhel_mgmt.redfish_command command on the control node to display the documentation of the module.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can remotely query information from of out-of-band (OOB) controllers through the Redfish API by using the redfish_info module of the redhat.rhel_mgmt collection. To display the returned value, register a variable with the fetched information, and display the content of this variable.

Important

When you use this Ansible module, three hosts are involved: the control node, the managed node, and the host with the OOB controller on which the actual operation is performed. The control node executes the playbook on the managed node, and the managed host connects to the remote OOB controller by using the Redfish API to execute the operation. For example, if you set hosts: managed-node-01.example.com and baseuri: server.example.com in the playbook, then managed-node-01.example.com executes the operation on server.example.com.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The ansible-collection-redhat-rhel_mgmt package is installed on the control node.
  • You have credentials to access the OOB controller, and these credentials have permissions to query settings.
  • The managed node can access the remote OOB controller over the network.

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      redfish_usr: <username>
redfish_pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Query information by using the Redfish API
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Get CPU inventory
      redhat.rhel_mgmt.redfish_info:
        baseuri: <uri>
        username: "{{ redfish_usr }}"
        password: "{{ redfish_pwd }}"
        category: Systems
        command: GetCpuInventory
      register: result

    - name: Display the fetched information
      ansible.builtin.debug:
        msg: "{{ result.redfish_facts.cpu.entries | to_nice_json }}"
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    baseuri: <uri>
    Defines the URI of the OOB controller. This is the OOB controller of the host on which the managed node performs the action.
    category: <value>

    Sets the category of the information to query. The following categories are available:

    • Accounts: User accounts of the OOB controller
    • Chassis: Chassis-related settings
    • Manager: Redfish services
    • Session: Redfish login sessions
    • Systems (default): Machine-related settings
    • Update: Firmware-related settings
    • All: Information from all categories.

    You can also set multiple categories if you use a list, for example ["Systems", "Accounts"].

    command: <command>
    Sets the query command to execute.

    For details about all variables used in the playbook, use the ansible-doc redhat.rhel_mgmt.redfish_info command on the control node to display the documentation of the module.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can configure BIOS, UEFI, and out-of-band (OOB) controllers settings through the Redfish API by using the redfish_config module of the redhat.rhel_mgmt collection. This enables you to modify the settings remotely with Ansible.

Important

When you use this Ansible module, three hosts are involved: the control node, the managed node, and the host with the OOB controller on which the actual operation is performed. The control node executes the playbook on the managed node, and the managed host connects to the remote OOB controller by using the Redfish API to execute the operation. For example, if you set hosts: managed-node-01.example.com and baseuri: server.example.com in the playbook, then managed-node-01.example.com executes the operation on server.example.com.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The ansible-collection-redhat-rhel_mgmt package is installed on the control node.
  • You have credentials to access the OOB controller, and these credentials have permissions to change settings.
  • The managed node can access the remote OOB controller over the network.

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      redfish_usr: <username>
redfish_pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configure BIOS/UEFI settings by using the Redfish API
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Change the boot mode to UEFI
      redhat.rhel_mgmt.redfish_config:
        baseuri: <uri>
        username: "{{ redfish_usr }}"
        password: "{{ redfish_pwd }}"
        category: Systems
        command: SetBiosAttributes
        bios_attributes:
          BootMode: "Uefi"
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    baseuri: <uri>
    Defines the URI of the OOB controller. This is the OOB controller of the host on which the managed node performs the action.
    category: <value>

    Sets the category of the command to execute. The following categories are available:

    • Accounts: Manages user accounts of the OOB controller.
    • Chassis: Manages chassis-related settings.
    • Manager: Provides access to Redfish services.
    • Session: Manages Redfish login sessions.
    • Systems (default): Manages machine-related settings.
    • Update: Manages firmware update-related actions.
    command: <command>
    Sets the command to execute. Depending on the command, it can be necessary to set additional variables.

    For details about all variables used in the playbook, use the ansible-doc redhat.rhel_mgmt.redfish_config command on the control node to display the documentation of the module.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can remotely configure and manage SELinux permissions by using the selinux RHEL system role.

For example, use the selinux role for the following tasks:

  • Cleaning local policy modifications related to SELinux booleans, file contexts, ports, and logins.
  • Setting SELinux policy booleans, file contexts, ports, and logins.
  • Restoring file contexts on specified files or directories.
  • Managing SELinux modules.

To remotely reset the SELinux context on directories, you can use the selinux RHEL system role. With an incorrect SELinux context, applications can fail to access the files.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing SELinux
  hosts: managed-node-01.example.com
  tasks:
    - name: Restore SELinux context
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.selinux
      vars:
        selinux_restore_dirs:
          - /var/www/
          - /etc/
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    selinux_restore_dirs: <list>
    Defines the list of directories on which the role should reset the SELinux context.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.selinux/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Display the SELinux context for files or directories for which you have reset the context. For example, to display the context on the /var/www/ directory, enter: 

    # ansible rhel9.example.com -m command -a 'ls -ldZ /var/www/'
drwxr-xr-x. 4 root root system_u:object_r:httpd_sys_content_t:s0 33 Feb 28 13:20 /var/www/
    Copy to Clipboard Toggle word wrap

If you want to run a service on a non-standard port, you must set the corresponding SELinux type label on this port to prevent that SELinux denies permission to the service. By using the selinux RHEL system role, you can automate this task and remotely assign a type label on ports.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing SELinux
  hosts: managed-node-01.example.com
  tasks:
    - name: Set http_port_t label on network port
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.selinux
      vars:
        selinux_ports:
          - ports: <port_number>
            proto: tcp
            setype: http_port_t
            state: present
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ports: <port_number>
    Defines the port numbers to which you want to assign the SELinux label. Separate multiple values by comma.
    setype: <type_label>
    Defines the SELinux type label.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.selinux/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Display the port numbers that have the http_port_t label assigned: 

    # ansible managed-node-01.example.com -m shell -a 'semanage port --list | grep http_port_t'
http_port_t      tcp     80, 81, 443, <port_number>, 488, 8008, 8009, 8443, 9000
    Copy to Clipboard Toggle word wrap

If the default SELinux policies do not meet your requirements, you can create custom modules to allow your application to access the required resources. By using the selinux RHEL system role, you can automate this process and remotely deploy SELinux modules.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The SELinux module you want to deploy is stored in the same directory as the playbook.

  • The SELinux module is available in the Common Intermediate Language (CIL) or policy package (PP) format.

    If you are using a PP module, ensure that policydb version on the managed nodes is the same or later than the version used to build the PP module.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing SELinux
  hosts: managed-node-01.example.com
  tasks:
    - name: Deploying a SELinux module
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.selinux
      vars:
        selinux_modules:
          - path: <module_file>
	    priority: <value>
            state: enabled
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    path: <module_file>
    Sets the path to the module file on the control node.
    priority: <value>
    Sets the SELinux module priority. 400 is the default.
    state: <value>

    Defines the state of the module:

    • enabled: Install or enable the module.
    • disabled: Disable a module.
    • absent: Remove a module.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.selinux/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Remotely display the list of SELinux modules and filter for the one you used in the playbook: 

    # ansible managed-node-01.example.com -m shell -a 'semodule -l | grep <module>'
    Copy to Clipboard Toggle word wrap

    If the module is listed, it is installed and enabled.

You can use the sshd RHEL system role to configure OpenSSH servers and the ssh RHEL system role to configure OpenSSH clients consistently, in an automated fashion, and on any number of RHEL systems at the same time.

Such configurations are necessary for any system where secure remote interaction is needed, for example:

  • Remote system administration: securely connecting to your machine from another computer using an SSH client.
  • Secure file transfers: the Secure File Transfer Protocol (SFTP) provided by OpenSSH enable you to securely transfer files between your local machine and a remote system.
  • Automated DevOps pipelines: automating software deployments that require secure connection to remote servers (CI/CD pipelines).
  • Tunneling and port forwarding: forwarding a local port to access a web service on a remote server behind a firewall. For example a remote database or a development server.
  • Key-based authentication: more secure alternative to password-based logins.
  • Certificate-based authentication: centralized trust management and better scalability.
  • Enhanced security: disabling root logins, restricting user access, enforcing strong encryption and other such forms of hardening ensures stronger system security.

In the sshd RHEL system role playbook, you can define the parameters for the server SSH configuration file. If you do not specify these settings, the role produces the sshd_config file that matches the RHEL defaults.

In all cases, booleans correctly render as yes and no in the final configuration on your managed nodes. You can use lists to define multi-line configuration items. For example: 

sshd_ListenAddress:
  - 0.0.0.0
  - '::'
Copy to Clipboard Toggle word wrap

renders as: 

ListenAddress 0.0.0.0
ListenAddress ::
Copy to Clipboard Toggle word wrap

You can use the sshd RHEL system role to configure multiple OpenSSH servers for secure remote access.

The role ensures secure communication environment for remote users by providing namely:

  • Management of incoming SSH connections from remote clients
  • Credentials verification
  • Secure data transfer and command execution
Note

You can use the sshd RHEL system role alongside with other RHEL system roles that change SSHD configuration, for example the Identity Management RHEL system roles. To prevent the configuration from being overwritten, ensure the sshd RHEL system role uses namespaces (RHEL 8 and earlier versions) or a drop-in directory (RHEL 9).

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: SSH server configuration
  hosts: managed-node-01.example.com
  tasks:
    - name: Configure sshd to prevent root and password login except from particular subnet
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.sshd
      vars:
        sshd_config:
          PermitRootLogin: no
          PasswordAuthentication: no
          Match:
            - Condition: "Address 192.0.2.0/24"
              PermitRootLogin: yes
              PasswordAuthentication: yes
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    PasswordAuthentication: yes|no
    Controls whether the OpenSSH server (sshd) accepts authentication from clients that use the username and password combination.
    Match:
    The match block allows the root user login using password only from the subnet 192.0.2.0/24.

    For details about the role variables and the OpenSSH configuration options used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.sshd/README.md file and the sshd_config(5) manual page on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. Log in to the SSH server: 

    $ ssh <username>@<ssh_server>
    Copy to Clipboard Toggle word wrap

  2. Verify the contents of the sshd_config file on the SSH server: 

    $ cat /etc/ssh/sshd_config.d/00-ansible_system_role.conf
#
# Ansible managed
#
PasswordAuthentication no
PermitRootLogin no
Match Address 192.0.2.0/24
  PasswordAuthentication yes
  PermitRootLogin yes
    Copy to Clipboard Toggle word wrap

  3. Check that you can connect to the server as root from the 192.0.2.0/24 subnet:

    1. Determine your IP address: 

      $ hostname -I
192.0.2.1
      Copy to Clipboard Toggle word wrap

      If the IP address is within the 192.0.2.1 - 192.0.2.254 range, you can connect to the server.

    2. Connect to the server as root: 

      $ ssh root@<ssh_server>
      Copy to Clipboard Toggle word wrap

By default, applying the sshd RHEL system role overwrites the entire configuration. This may be problematic if you have previously adjusted the configuration with a different playbook. You can use the non-exclusive configuration to apply changes only to selected configuration options.

You can apply a non-exclusive configuration:

  • In RHEL 8 and earlier by using a configuration snippet.
  • In RHEL 9 and later by using files in a drop-in directory. The default configuration file is already placed in the drop-in directory as /etc/ssh/sshd_config.d/00-ansible_system_role.conf.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content:

    • For managed nodes that run RHEL 8 or earlier: 

      ---
- name: Non-exclusive sshd configuration
  hosts: managed-node-01.example.com
  tasks:
    - name: Configure SSHD to accept environment variables
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.sshd
      vars:
        sshd_config_namespace: <my-application>
        sshd_config:
          # Environment variables to accept
          AcceptEnv:
            LANG
            LS_COLORS
            EDITOR
      Copy to Clipboard Toggle word wrap

    • For managed nodes that run RHEL 9 or later: 

      - name: Non-exclusive sshd configuration
  hosts: managed-node-01.example.com
  tasks:
    - name: Configure sshd to accept environment variables
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.sshd
      vars:
        sshd_config_file: /etc/ssh/sshd_config.d/<42-my-application>.conf
        sshd_config:
          # Environment variables to accept
          AcceptEnv:
            LANG
            LS_COLORS
            EDITOR
      Copy to Clipboard Toggle word wrap

      The settings specified in the example playbooks include the following:

      sshd_config_namespace: <my-application>
      The role places the configuration that you specify in the playbook to configuration snippets in the existing configuration file under the given namespace. You need to select a different namespace when running the role from different context.
      sshd_config_file: /etc/ssh/sshd_config.d/<42-my-application>.conf
      In the sshd_config_file variable, define the .conf file into which the sshd system role writes the configuration options. Use a two-digit prefix, for example 42- to specify the order in which the configuration files will be applied.
      AcceptEnv:

      Controls which environment variables the OpenSSH server (sshd) will accept from a client:

      • LANG: defines the language and locale settings.
      • LS_COLORS: defines the displaying color scheme for the ls command in the terminal.
      • EDITOR: specifies the default text editor for the command-line programs that need to open an editor.

      For details about the role variables and the OpenSSH configuration options used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.sshd/README.md file and the sshd_config(5) manual page on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Verify the configuration on the SSH server:

    • For managed nodes that run RHEL 8 or earlier: 

      # cat /etc/ssh/sshd_config
...
# BEGIN sshd system role managed block: namespace <my-application>
Match all
  AcceptEnv LANG LS_COLORS EDITOR
# END sshd system role managed block: namespace <my-application>
      Copy to Clipboard Toggle word wrap

    • For managed nodes that run RHEL 9 or later: 

      # cat /etc/ssh/sshd_config.d/42-my-application.conf
# Ansible managed
#
AcceptEnv LANG LS_COLORS EDITOR
      Copy to Clipboard Toggle word wrap

When the default cryptographic settings do not meet certain security or compatibility needs, you may want to override the system-wide cryptographic policy on the OpenSSH server by using the sshd RHEL system role.

Override the system-wide cryptographic policy in the following notable situations:

  • Compatibility with older clients: necessity to use weaker-than-default encryption algorithms, key exchange protocols, or ciphers.
  • Enforcing stronger security policies: simultaneously, you can disable weaker algorithms. Such a measure could exceed the default system cryptographic policies, especially in the highly secure and regulated environments.
  • Performance considerations: the system defaults could enforce stronger algorithms that can be computationally intensive for some systems.
  • Customizing for specific security needs: adapting for unique requirements that are not covered by the default cryptographic policies.
Warning

It is not possible to override all aspects of the cryptographic policies from the sshd RHEL system role. For example, SHA1 signatures might be forbidden on a different layer so for a more generic solution, see Setting a custom cryptographic policy by using RHEL system roles.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    - name: Deploy SSH configuration for OpenSSH server
  hosts: managed-node-01.example.com
  tasks:
    - name: Overriding the system-wide cryptographic policy
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.sshd
      vars:
        sshd_sysconfig: true
        sshd_sysconfig_override_crypto_policy: true
        sshd_KexAlgorithms: ecdh-sha2-nistp521
        sshd_Ciphers: aes256-ctr
        sshd_MACs: hmac-sha2-512-etm@openssh.com
        sshd_HostKeyAlgorithms: rsa-sha2-512,rsa-sha2-256
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    sshd_KexAlgorithms
    You can choose key exchange algorithms, for example, ecdh-sha2-nistp256, ecdh-sha2-nistp384, ecdh-sha2-nistp521,diffie-hellman-group14-sha1, or diffie-hellman-group-exchange-sha256.
    sshd_Ciphers
    You can choose ciphers, for example, aes128-ctr, aes192-ctr, or aes256-ctr.
    sshd_MACs
    You can choose MACs, for example, hmac-sha2-256, hmac-sha2-512, or hmac-sha1.
    sshd_HostKeyAlgorithms
    You can choose a public key algorithm, for example, ecdsa-sha2-nistp256, ecdsa-sha2-nistp384, ecdsa-sha2-nistp521, or ssh-rsa.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.sshd/README.md file on the control node.

    On RHEL 9 managed nodes, the system role writes the configuration into the /etc/ssh/sshd_config.d/00-ansible_system_role.conf file, where cryptographic options are applied automatically. You can change the file by using the sshd_config_file variable. However, to ensure the configuration is effective, use a file name that lexicographically precedes the /etc/ssh/sshd_config.d/50-redhat.conf file, which includes the configured crypto policies.

    On RHEL 8 managed nodes, you must enable override by setting the sshd_sysconfig_override_crypto_policy and sshd_sysconfig variables to true.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • You can verify the success of the procedure by using the verbose SSH connection and check the defined variables in the following output: 

    $ ssh -vvv <ssh_server>
...
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: ecdh-sha2-nistp521
debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256
debug2: ciphers ctos: aes256-ctr
debug2: ciphers stoc: aes256-ctr
debug2: MACs ctos: hmac-sha2-512-etm@openssh.com
debug2: MACs stoc: hmac-sha2-512-etm@openssh.com
...
    Copy to Clipboard Toggle word wrap

In the ssh RHEL system role playbook, you can define the parameters for the client SSH configuration file. If you do not specify these settings, the role produces a global ssh_config file that matches the RHEL defaults.

In all the cases, booleans correctly render as yes or no in the final configuration on your managed nodes. You can use lists to define multi-line configuration items. For example: 

LocalForward:
  - 22 localhost:2222
  - 403 localhost:4003
Copy to Clipboard Toggle word wrap

renders as: 

LocalForward 22 localhost:2222
LocalForward 403 localhost:4003
Copy to Clipboard Toggle word wrap
Note

The configuration options are case sensitive.

You can use the ssh RHEL system role to configure multiple OpenSSH clients.

OpenSSH clients enable the local user to establish a secure connection with the remote OpenSSH server by ensuring namely:

  • Secure connection initiation
  • Credentials provision
  • Negotiation with the OpenSSH server on the encryption method used for the secure communication channel
  • Ability to send files securely to and from the OpenSSH server
Note

You can use the ssh RHEL system role alongside with other system roles that change SSH configuration, for example the Identity Management RHEL system roles. To prevent the configuration from being overwritten, make sure that the ssh RHEL system role uses a drop-in directory (default in RHEL 8 and later).

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: SSH client configuration
  hosts: managed-node-01.example.com
  tasks:
    - name: Configure ssh clients
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.ssh
      vars:
        ssh_user: root
        ssh:
          Compression: true
          GSSAPIAuthentication: no
          ControlMaster: auto
          ControlPath: ~/.ssh/.cm%C
          Host:
            - Condition: example
              Hostname: server.example.com
              User: user1
        ssh_ForwardX11: no
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    ssh_user: root
    Configures the root user’s SSH client preferences on the managed nodes with certain configuration specifics.
    Compression: true
    Compression is enabled.
    ControlMaster: auto
    ControlMaster multiplexing is set to auto.
    Host
    Creates alias example for connecting to the server.example.com host as a user called user1.
    ssh_ForwardX11: no
    X11 forwarding is disabled.

    For details about the role variables and the OpenSSH configuration options used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.ssh/README.md file and the ssh_config(5) manual page on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Verify that the managed node has the correct configuration by displaying the SSH configuration file: 

    # cat ~/root/.ssh/config
# Ansible managed
Compression yes
ControlMaster auto
ControlPath ~/.ssh/.cm%C
ForwardX11 no
GSSAPIAuthentication no
Host example
  Hostname example.com
  User user1
    Copy to Clipboard Toggle word wrap

To manage LVM and local file systems (FS) by using Ansible, you can use the storage role. Using the storage role enables you to automate administration of file systems on disks and logical volumes on multiple machines.

You can use the storage RHEL system role to automate the creation of an XFS file system on block devices.

Note

The storage role can create a file system only on an unpartitioned, whole disk or a logical volume (LV). It cannot create the file system on a partition.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage local storage
  hosts: managed-node-01.example.com
  tasks:
    - name: Create an XFS file system on a block device
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.storage
      vars:
        storage_volumes:
          - name: barefs
            type: disk
            disks:
              - sdb
            fs_type: xfs
    Copy to Clipboard Toggle word wrap

    The setting specified in the example playbook include the following:

    name: barefs
    The volume name (barefs in the example) is currently arbitrary. The storage role identifies the volume by the disk device listed under the disks attribute.
    fs_type: <file_system>
    You can omit the fs_type parameter if you want to use the default file system XFS.
    disks: <list_of_disks_and_volumes>

    A YAML list of disk and LV names. To create the file system on an LV, provide the LVM setup under the disks attribute, including the enclosing volume group. For details, see Creating or resizing a logical volume by using the storage RHEL system role.

    Do not provide the path to the LV device.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.storage/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the storage RHEL system role to persistently mount file systems to ensure they remain available across system reboots and are automatically mounted on startup. If the file system on the device you specified in the playbook does not exist, the role creates it.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage local storage
  hosts: managed-node-01.example.com
  tasks:
    - name: Persistently mount a file system
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.storage
      vars:
        storage_volumes:
          - name: barefs
            type: disk
            disks:
              - sdb
            fs_type: xfs
            mount_point: /mnt/data
            mount_user: somebody
            mount_group: somegroup
            mount_mode: 0755
    Copy to Clipboard Toggle word wrap

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.storage/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

You can use the storage RHEL system role to create and resize LVM logical volumes. The role automatically creates volume groups when if they do not exist.

Use the storage role to perform the following tasks:

  • To create an LVM logical volume in a volume group consisting of many disks
  • To resize an existing file system on LVM
  • To express an LVM volume size in percentage of the pool’s total size

If the volume group does not exist, the role creates it. If a logical volume exists in the volume group, it is resized if the size does not match what is specified in the playbook.

If you are reducing a logical volume, to prevent data loss you must ensure that the file system on that logical volume is not using the space in the logical volume that is being reduced.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage local storage
  hosts: managed-node-01.example.com
  tasks:
    - name: Create logical volume
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.storage
      vars:
        storage_pools:
          - name: myvg
            disks:
              - sda
              - sdb
              - sdc
            volumes:
              - name: mylv
                size: 2G
                fs_type: ext4
                mount_point: /mnt/data
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    size: <size>
    You must specify the size by using units (for example, GiB) or percentage (for example, 60%).

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.storage/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Verify that specified volume has been created or resized to the requested size: 

    # ansible managed-node-01.example.com -m command -a 'lvs myvg'
    Copy to Clipboard Toggle word wrap

You can mount an XFS file system with the online block discard option to automatically discard unused blocks.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage local storage
  hosts: managed-node-01.example.com
  tasks:
    - name: Enable online block discard
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.storage
      vars:
        storage_volumes:
          - name: barefs
            type: disk
            disks:
              - sdb
            fs_type: xfs
            mount_point: /mnt/data
            mount_options: discard
    Copy to Clipboard Toggle word wrap

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.storage/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Verify that online block discard option is enabled: 

    # ansible managed-node-01.example.com -m command -a 'findmnt /mnt/data'
    Copy to Clipboard Toggle word wrap

You can use the storage RHEL system role to create and mount file systems that persist across reboots. The role automatically adds entries to /etc/fstab to ensure persistent mounting.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage local storage
  hosts: managed-node-01.example.com
  tasks:
    -name: Create and mount a file system
    ansible.builtin.include_role:
        name: redhat.rhel_system_roles.storage
    vars:
      storage_volumes:
        - name: barefs
          type: disk
          disks:
            - sdb
          fs_type: ext4
          fs_label: label-name
          mount_point: /mnt/data
    Copy to Clipboard Toggle word wrap

    The setting specified in the example playbook include the following:

    disks: <list_of_devices>
    A YAML list of device names that the role uses when it creates the volume.
    fs_type: <file_system>
    Specifies the file system the role should set on the volume. You can select xfs, ext3, ext4, swap, or unformatted.
    label-name: <file_system_label>
    Optional: sets the label of the file system.
    mount_point: <directory>
    Optional: if the volume should be automatically mounted, set the mount_point variable to the directory to which the volume should be mounted.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.storage/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

With the storage system role, you can configure a RAID volume on RHEL by using Red Hat Ansible Automation Platform and Ansible-Core. Create an Ansible playbook with the parameters to configure a RAID volume to suit your requirements.

Warning

Device names might change in certain circumstances, for example, when you add a new disk to a system. Therefore, to prevent data loss, use persistent naming attributes in the playbook. For more information about persistent naming attributes, see Persistent naming attributes.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage local storage
  hosts: managed-node-01.example.com
  tasks:
    - name: Create a RAID on sdd, sde, sdf, and sdg
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.storage
      vars:
        storage_safe_mode: false
        storage_volumes:
          - name: data
            type: raid
            disks: [sdd, sde, sdf, sdg]
            raid_level: raid0
            raid_chunk_size: 32 KiB
            mount_point: /mnt/data
            state: present
    Copy to Clipboard Toggle word wrap

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.storage/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Verify that the array was correctly created: 

    # ansible managed-node-01.example.com -m command -a 'mdadm --detail /dev/md/data'
    Copy to Clipboard Toggle word wrap

You can use the storage RHEL system role to configure stripe sizes for RAID LVM volumes.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage local storage
  hosts: managed-node-01.example.com
  tasks:
    - name: Configure stripe size for RAID LVM volumes
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.storage
      vars:
        storage_safe_mode: false
        storage_pools:
          - name: my_pool
            type: lvm
            disks: [sdh, sdi]
            volumes:
              - name: my_volume
                size: "1 GiB"
                mount_point: "/mnt/app/shared"
                fs_type: xfs
                raid_level: raid0
                raid_stripe_size: "256 KiB"
                state: present
    Copy to Clipboard Toggle word wrap

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.storage/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Verify that stripe size is set to the required size: 

    # ansible managed-node-01.example.com -m command -a 'lvs -o+stripesize /dev/my_pool/my_volume'
    Copy to Clipboard Toggle word wrap

You can use the storage RHEL system role to create a VDO volume on LVM (LVM-VDO) with enabled compression and deduplication.

Note

Because of the storage system role use of LVM-VDO, only one volume can be created per pool.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage local storage
  hosts: managed-node-01.example.com
  tasks:
    - name: Create LVM-VDO volume under volume group 'myvg'
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.storage
      vars:
        storage_pools:
          - name: myvg
            disks:
              - /dev/sdb
            volumes:
              - name: mylv1
                compression: true
                deduplication: true
                vdo_pool_size: 10 GiB
                size: 30 GiB
                mount_point: /mnt/app/shared
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    vdo_pool_size: <size>
    The actual size that the volume takes on the device. You can specify the size in human-readable format, such as 10 GiB. If you do not specify a unit, it defaults to bytes.
    size: <size>
    The virtual size of VDO volume.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.storage/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • View the current status of compression and deduplication: 

    $ ansible managed-node-01.example.com -m command -a 'lvs -o+vdo_compression,vdo_compression_state,vdo_deduplication,vdo_index_state'
  LV       VG      Attr       LSize   Pool   Origin Data%  Meta%  Move Log Cpy%Sync Convert VDOCompression VDOCompressionState VDODeduplication VDOIndexState
  mylv1   myvg   vwi-a-v---   3.00t vpool0                                                         enabled              online          enabled        online
    Copy to Clipboard Toggle word wrap

You can use the storage role to create and configure a volume encrypted with LUKS by running an Ansible playbook.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      luks_password: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage local storage
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Create and configure a volume encrypted with LUKS
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.storage
      vars:
        storage_volumes:
          - name: barefs
            type: disk
            disks:
              - sdb
            fs_type: xfs
            fs_label: <label>
            mount_point: /mnt/data
            encryption: true
            encryption_password: "{{ luks_password }}"
    Copy to Clipboard Toggle word wrap

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.storage/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. Find the luksUUID value of the LUKS encrypted volume: 

    # ansible managed-node-01.example.com -m command -a 'cryptsetup luksUUID /dev/sdb'

4e4e7970-1822-470e-b55a-e91efe5d0f5c
    Copy to Clipboard Toggle word wrap

  2. View the encryption status of the volume: 

    # ansible managed-node-01.example.com -m command -a 'cryptsetup status luks-4e4e7970-1822-470e-b55a-e91efe5d0f5c'

/dev/mapper/luks-4e4e7970-1822-470e-b55a-e91efe5d0f5c is active and is in use.
  type:    LUKS2
  cipher:  aes-xts-plain64
  keysize: 512 bits
  key location: keyring
  device:  /dev/sdb
...
    Copy to Clipboard Toggle word wrap

  3. Verify the created LUKS encrypted volume: 

    # ansible managed-node-01.example.com -m command -a 'cryptsetup luksDump /dev/sdb'

LUKS header information
Version:        2
Epoch:          3
Metadata area:  16384 [bytes]
Keyslots area:  16744448 [bytes]
UUID:           4e4e7970-1822-470e-b55a-e91efe5d0f5c
Label:          (no label)
Subsystem:      (no subsystem)
Flags:          (no flags)

Data segments:
  0: crypt
        offset: 16777216 [bytes]
        length: (whole device)
        cipher: aes-xts-plain64
        sector: 512 [bytes]
...
    Copy to Clipboard Toggle word wrap

You can use the storage RHEL system role to create shared LVM devices if you want your multiple systems to access the same storage at the same time.

This can bring the following notable benefits:

  • Resource sharing
  • Flexibility in managing storage resources
  • Simplification of storage management tasks

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage local storage
  hosts: managed-node-01.example.com
  become: true
  tasks:
    - name: Create shared LVM device
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.storage
      vars:
        storage_pools:
          - name: vg1
            disks: /dev/vdb
            type: lvm
            shared: true
            state: present
            volumes:
              - name: lv1
                size: 4g
                mount_point: /opt/test1
        storage_safe_mode: false
        storage_use_partitions: true
    Copy to Clipboard Toggle word wrap

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.storage/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

With the storage system role, you can resize LVM physical volumes after resizing the underlying storage or disks from outside of the host. For example, you increased the size of a virtual disk and want to use the extra space in an existing LVM.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The size of the underlying block storage has been changed.

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage local storage
  hosts: managed-node-01.example.com
  tasks:
    - name: Resize LVM PV size
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.storage
      vars:
        storage_pools:
           - name: myvg
             disks: ["sdf"]
             type: lvm
             grow_to_fill: true
    Copy to Clipboard Toggle word wrap

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.storage/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Display the new physical volume size: 

    $ ansible managed-node-01.example.com -m command -a 'pvs'
PV         VG   Fmt Attr PSize PFree
/dev/sdf1 myvg lvm2 a-- 1,99g 1,99g
    Copy to Clipboard Toggle word wrap

To secure your data, you can create an encrypted Stratis pool with the storage RHEL system role. In addition to a passphrase, you can use Clevis and Tang or TPM protection as an encryption method.

Important

You can configure Stratis encryption only on the entire pool.

Prerequisites

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      luks_password: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Manage local storage
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Create a new encrypted Stratis pool with Clevis and Tang
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.storage
      vars:
        storage_pools:
           - name: mypool
             disks:
               - sdd
               - sde
             type: stratis
             encryption: true
             encryption_password: "{{ luks_password }}"
             encryption_clevis_pin: tang
             encryption_tang_url: tang-server.example.com:7500
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    encryption_password
    Password or passphrase used to unlock the LUKS volumes.
    encryption_clevis_pin
    Clevis method that you can use to encrypt the created pool. You can use tang and tpm2.
    encryption_tang_url
    URL of the Tang server.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.storage/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Verify that the pool was created with Clevis and Tang configured: 

    $ ansible managed-node-01.example.com -m command -a 'sudo stratis report'
...
                        "clevis_config": {
                            "thp": "j-G4ddvdbVfxpnUbgxlpbe3KutSKmcHttILAtAkMTNA",
                            "url": "tang-server.example.com:7500"
                        },
                        "clevis_pin": "tang",
                        "in_use": true,
                        "key_description": "blivet-mypool",
    Copy to Clipboard Toggle word wrap

Chapter 27. Using the sudo RHEL system role
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You can consistently configure the /etc/sudoers files on multiple systems by using the sudo RHEL system role.

You can use the sudo RHEL system role to apply custom sudoers configuration on your managed nodes. That way, you can define which users can run which commands on which hosts, with better configuration efficiency and more granular control.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: "Configure sudo"
  hosts: managed-node-01.example.com
  tasks:
    - name: "Apply custom /etc/sudoers configuration"
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.sudo
      vars:
        sudo_sudoers_files:
          - path: "/etc/sudoers"
            user_specifications:
              - users:
                  - <user_name>
                hosts:
                  - <host_name>
                commands:
                  - <path_to_command_binary>
    Copy to Clipboard Toggle word wrap

    The settings specified in the playbook include the following:

    users
    The list of users that the rule applies to.
    hosts
    The list of hosts that the rule applies to. You can use ALL for all hosts.
    commands

    The list of commands that the rule applies to. You can use ALL for all commands.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.sudo/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. On the managed node, verify that the playbook applied the new rules. 

    # cat /etc/sudoers | tail -n1
<user_name> <host_name>= <path_to_command_binary>
    Copy to Clipboard Toggle word wrap

By using the systemd RHEL system role, you can automate certain systemd-related tasks and perform them remotely.

You can use the systemd role for the following actions:

  • Manage services
  • Deploy units
  • Deploy drop-in files

You can automate and remotely manage systemd units, such as starting or enabling services, by using the systemd RHEL system role.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content. Use only the variables depending on what actions you want to perform. 

    ---
- name: Managing systemd services
  hosts: managed-node-01.example.com
  tasks:
    - name: Perform action on systemd units
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.systemd
      vars:
        systemd_started_units:
          - <systemd_unit_1>.service
        systemd_stopped_units:
          - <systemd_unit_2>.service
        systemd_restarted_units:
          - <systemd_unit_3>.service
        systemd_reloaded_units:
          - <systemd_unit_4>.service
        systemd_enabled_units:
          - <systemd_unit_5>.service
        systemd_disabled_units:
          - <systemd_unit_6>.service
        systemd_masked_units:
          - <systemd_unit_7>.service
        systemd_unmasked_units:
          - <systemd_unit_8>.service
    Copy to Clipboard Toggle word wrap

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.systemd/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Systemd applies drop-in files on top of setting it reads for a unit from other locations. Therefore, you can modify unit settings with drop-in files without changing the original unit file. By using the systemd RHEL system role, you can automate the process of deploying drop-in files.

Important

The role uses the hard-coded file name 99-override.conf to store drop-in files in /etc/systemd/system/<name>._<unit_type>/. Note that it overrides existing files with this name in the destination directory.

Prerequisites

Procedure

  1. Create a Jinja2 template with the systemd drop-in file contents. For example, create the ~/sshd.service.conf.j2 file with the following content: 

    {{ ansible_managed | comment }}
[Unit]
After=
After=network.target sshd-keygen.target network-online.target
    Copy to Clipboard Toggle word wrap

    This drop-in file specifies the same units in the After setting as the original /usr/lib/systemd/system/sshd.service file and, additionally, network-online.target. With this extra target, sshd starts after the network interfaces are actived and have IP addresses assigned. This ensures that sshd can bind to all IP addresses.

    Use the <name>.<unit_type>.conf.j2 convention for the file name. For example, to add a drop-in for the sshd.service unit, you must name the file sshd.service.conf.j2. Place the file in the same directory as the playbook.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing systemd services
  hosts: managed-node-01.example.com
  tasks:
    - name: Deploy an sshd.service systemd drop-in file
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.systemd
      vars:
         systemd_dropins:
           - sshd.service.conf.j2
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    systemd_dropins: <list_of_files>
    Specifies the names of the drop-in files to deploy in YAML list format.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.systemd/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Verify that the role placed the drop-in file in the correct location: 

    # ansible managed-node-01.example.com -m command -a 'ls /etc/systemd/system/sshd.service.d/'
99-override.conf
    Copy to Clipboard Toggle word wrap

You can create unit files for custom applications, and systemd reads them from the /etc/systemd/system/ directory. By using the systemd RHEL system role, you can automate the deployment of custom unit files.

Prerequisites

Procedure

  1. Create a Jinja2 template with the custom systemd unit file contents. For example, create the ~/example.service.j2 file with the contents for your service: 

    {{ ansible_managed | comment }}
[Unit]
Description=Example systemd service unit file

[Service]
ExecStart=/bin/true
    Copy to Clipboard Toggle word wrap

    Use the <name>.<unit_type>.j2 convention for the file name. For example, to create the example.service unit, you must name the file example.service.j2. Place the file in the same directory as the playbook.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing systemd services
  hosts: managed-node-01.example.com
  tasks:
    - name: Deploy, enable, and start a custom systemd service
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.systemd
      vars:
         systemd_unit_file_templates:
           - example.service.j2
         systemd_enabled_units:
           - example.service
         systemd_started_units:
           - example.service
    Copy to Clipboard Toggle word wrap

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.systemd/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Verify that the service is enabled and started: 

    # ansible managed-node-01.example.com -m command -a 'systemctl status example.service'
...
● example.service - A service for demonstrating purposes
   Loaded: loaded (/etc/systemd/system/example.service; enabled; vendor preset: disabled)
   Active: active (running) since Thu 2024-07-04 15:59:18 CEST; 10min ago
...
    Copy to Clipboard Toggle word wrap

You can create per-user unit files for custom applications, and systemd reads them from the /home/<username>/.config/systemd/user/ directory. By using the systemd RHEL system role, you can automate the deployment of custom unit files for individual users.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • The user you specify in the playbook for the systemd unit exists.

Procedure

  1. Create a Jinja2 template with the custom systemd unit file contents. For example, create the ~/example.service.j2 file with the contents for your service: 

    {{ ansible_managed | comment }}
[Unit]
Description=Example systemd service unit file

[Service]
ExecStart=/bin/true
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target
    Copy to Clipboard Toggle word wrap

    Use the <name>.<unit_type>.j2 convention for the file name. For example, to create the example.service unit, you must name the file example.service.j2. Place the file in the same directory as the playbook.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing systemd services
  hosts: managed-node-01.example.com
  tasks:
    - name: Deploy, enable, and start a custom systemd service for a user
      ansible.builtin.include_role:
        name: rhel-system-roles.systemd
      vars:
        systemd_unit_file_templates:
          - item: example.service.j2
            user: <username>
        systemd_enabled_units:
          - item: example.service
            user: <username>
        systemd_started_units:
          - item: example.service
            user: <username>
    Copy to Clipboard Toggle word wrap
    Important

    The systemd RHEL system role does not create new users, and it returns an error if you specify a non-existent user in the playbook.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.systemd/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Verify that the service is enabled and started: 

    # ansible managed-node-01.example.com -m command -a 'systemctl --user -M <username>@ status example.service'
...
● example.service - Example systemd service unit file
     Loaded: loaded (/home/<username>/.config/systemd/user/example.service; enabled; preset: disabled)
     Active: active (exited) since Wed 2025-03-05 13:33:36 CET; 45s ago
...
    Copy to Clipboard Toggle word wrap

The Network Time Protocol (NTP) and Precision Time Protocol (PTP) are standards to synchronize the clock of computers over a network. By using the timesync RHEL system role, you can automate the configuration of time synchronization on RHEL.

An accurate time synchronization in networks is important because certain services rely on it. For example, Kerberos tolerates only a small time difference between the server and client to prevent replay attacks.

You can set the time service to configure in the timesync_ntp_provider variable of a playbook. If you do not set this variable, the role determines the time service based on the following factors:

  • On RHEL 8 and later: chronyd
  • On RHEL 6 and 7: chronyd (default) or, if already installed ntpd.

The Network Time Protocol (NTP) synchronizes the time of a host with an NTP server over a network. By using the timesync RHEL system role, you can automate the configuration of RHEL NTP clients in your network and keep the time synchronized.

Warning

The timesync RHEL system role replaces the configuration of the specified given or detected provider service on the managed host. Consequently, all settings are lost if they are not specified in the playbook.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing time synchronization
  hosts: managed-node-01.example.com
  tasks:
    - name: Configuring NTP with an internal server (preferred) and a public server pool as fallback
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.timesync
      vars:
        timesync_ntp_servers:
        - hostname: time.example.com
          trusted: yes
          prefer: yes
          iburst: yes
        - hostname: 0.rhel.pool.ntp.org
          pool: yes
          iburst: yes
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    pool: <yes|no>
    Flags a source as an NTP pool rather than an individual host. In this case, the service expects that the name resolves to multiple IP addresses which can change over time.
    iburst: yes
    Enables fast initial synchronization.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.timesync/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Display the details about the time sources:

    • If the managed node runs the chronyd service, enter: 

      # ansible managed-node-01.example.com -m command -a 'chronyc sources'
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^* time.example.com              1  10   377   210   +159us[  +55us] +/-   12ms
^? ntp.example.org               2   9   377   409  +1120us[+1021us] +/-   42ms
^? time.us.example.net           2   9   377   992   -329us[ -386us] +/-   15ms
...
      Copy to Clipboard Toggle word wrap

    • If the managed node runs the ntpd service, enter: 

      # ansible managed-node-01.example.com -m command -a 'ntpq -p'
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*time.example.com .PTB.           1 u    2   64   77   23.585  967.902   0.684
- ntp.example.or 192.0.2.17       2 u    -   64   77   27.090  966.755   0.468
+time.us.example 198.51.100.19    2 u   65   64   37   18.497  968.463   1.588
...
      Copy to Clipboard Toggle word wrap

By using the Network Time Security (NTS) mechanism, clients establish a TLS-encrypted connection to the server and authenticate Network Time Protocol (NTP) packets. By using the timesync RHEL system role, you can automate the configuration of RHEL NTP clients with NTS.

Note that you cannot mix NTS servers with non-NTS servers. In mixed configurations, NTS servers are trusted and clients do not fall back to unauthenticated NTP sources because they can be exploited in man-in-the-middle (MITM) attacks. For further details, see the authselectmode parameter description in the chrony.conf(5) man page on your system.

Warning

The timesync RHEL system role replaces the configuration of the specified given or detected provider service on the managed host. Consequently, all settings are lost if they are not specified in the playbook.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Managing time synchronization
  hosts: managed-node-01.example.com
  tasks:
    - name: Configuring NTP with NTS-enabled servers
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.timesync
      vars:
        timesync_ntp_servers:
        - hostname: ptbtime1.ptb.de
          nts: yes
          iburst: yes
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    iburst: yes
    Enables fast initial synchronization.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.timesync/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • If the managed node runs the chronyd service:

    1. Display the details about the time sources: 

      # ansible managed-node-01.example.com -m command -a 'chronyc sources'
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^* ptbtime1.ptb.de               1   6    17    55    -13us[  -54us] +/-   12ms
^- ptbtime2.ptb.de               1   6    17    56   -257us[ -297us] +/-   12ms
      Copy to Clipboard Toggle word wrap

    2. For sources with NTS enabled, display information that is specific to authentication of NTP sources: 

      # ansible managed-node-01.example.com -m command -a 'chronyc -N authdata'
Name/IP address             Mode KeyID Type KLen Last Atmp  NAK Cook CLen
=========================================================================
ptbtime1.ptb.de              NTS     1   15  256  229    0    0    8  100
ptbtime2.ptb.de              NTS     1   15  256  230    0    0    8  100
      Copy to Clipboard Toggle word wrap

      Verify that the reported cookies in the Cook column is larger than 0.

  • If the managed node runs the ntpd service, enter: 

    # ansible managed-node-01.example.com -m command -a 'ntpq -p'
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*ptbtime1.ptb.de .PTB.            1 8    2   64   77   23.585  967.902   0.684
-ptbtime2.ptb.de .PTB.            1 8   30   64   78   24.653  993.937   0.765
    Copy to Clipboard Toggle word wrap

Use the tlog RHEL system role to record and monitor terminal session activities on your managed nodes in an automatic fashion. You can configure the recording to take place per user or user group by means of the SSSD service.

The session recording solution in the tlog RHEL system role consists of the following components:

  • The tlog utility
  • System Security Services Daemon (SSSD)
  • Optional: The web console interface

Prepare and apply an Ansible playbook to configure a RHEL system to log session recording data to the systemd journal. With that, you can enable recording the terminal output and input of a specific user during their sessions, when the user logs in on the console, or by SSH.

The playbook installs tlog-rec-session, a terminal session I/O logging program, that acts as the login shell for a user. The role creates an SSSD configuration drop file, and this file defines for which users and groups the login shell should be used. Additionally, if the cockpit package is installed on the system, the playbook also installs the cockpit-session-recording package, which is a Cockpit module that allows you to view and play recordings in the web console interface.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Deploy session recording
  hosts: managed-node-01.example.com
  tasks:
    - name: Enable session recording for specific users
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.tlog
  vars:
    tlog_scope_sssd: some
    tlog_users_sssd:
      - <recorded_user>
    Copy to Clipboard Toggle word wrap
    tlog_scope_sssd: <value>
    The some value specifies you want to record only certain users and groups, not all or none.
    tlog_users_sssd: <list_of_users>
    A YAML list of users you want to record a session from. Note that the role does not add users if they do not exist.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. Check the SSSD drop-in file’s content: 

    # cd /etc/sssd/conf.d/sssd-session-recording.conf
    Copy to Clipboard Toggle word wrap

    You can see that the file contains the parameters you set in the playbook.

  2. Log in as a user whose session will be recorded, perform some actions, and log out.

  3. As the root user:

    1. Display the list of recorded sessions: 

      # journalctl _COMM=tlog-rec-sessio
Nov 12 09:17:30 managed-node-01.example.com -tlog-rec-session[1546]: {"ver":"2.3","host":"managed-node-01.example.com","rec":"07418f2b0f334c1696c10cbe6f6f31a6-60a-e4a2","user":"demo-user",...
...
      Copy to Clipboard Toggle word wrap

      You require the value of the rec (recording ID) field in the next step.

      Note that the value of the _COMM field is shortened due to a 15 character limit.

    2. Play back a session: 

      # tlog-play -r journal -M TLOG_REC=<recording_id>
      Copy to Clipboard Toggle word wrap

You can use the tlog_exclude_users_sssd and tlog_exclude_groups_sssd role variables from the tlog RHEL system role to exclude users or groups from having their sessions recorded and logged in the systemd journal.

The playbook installs tlog-rec-session, a terminal session I/O logging program, that acts as the login shell for a user. The role creates an SSSD configuration drop file, and this file defines for which users and groups the login shell should be used. Additionally, if the cockpit package is installed on the system, the playbook also installs the cockpit-session-recording package, which is a Cockpit module that allows you to view and play recordings in the web console interface.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Deploy session recording excluding users and groups
  hosts: managed-node-01.example.com
  tasks:
    - name: Exclude users and groups
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.tlog
      vars:
        tlog_scope_sssd: all
        tlog_exclude_users_sssd:
          - jeff
          - james
        tlog_exclude_groups_sssd:
          - admins
    Copy to Clipboard Toggle word wrap
    tlog_scope_sssd: <value>
    The value all specifies that you want to record all users and groups.
    tlog_exclude_users_sssd: <user_list>
    A YAML list of users user names you want to exclude from the session recording.
    tlog_exclude_groups_sssd: <group_list>
    A YAML list of groups you want to exclude from the session recording.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. Check the SSSD drop-in file’s content: 

    # cat /etc/sssd/conf.d/sssd-session-recording.conf
    Copy to Clipboard Toggle word wrap

    You can see that the file contains the parameters you set in the playbook.

  2. Log in as a user whose session will be recorded, perform some actions, and log out.

  3. As the root user:

    1. Display the list of recorded sessions: 

      # journalctl _COMM=tlog-rec-sessio
Nov 12 09:17:30 managed-node-01.example.com -tlog-rec-session[1546]: {"ver":"2.3","host":"managed-node-01.example.com","rec":"07418f2b0f334c1696c10cbe6f6f31a6-60a-e4a2","user":"demo-user",...
...
      Copy to Clipboard Toggle word wrap

      You require the value of the rec (recording ID) field in the next step.

      Note that the value of the _COMM field is shortened due to a 15 character limit.

    2. Play back a session: 

      # tlog-play -r journal -M TLOG_REC=<recording_id>
      Copy to Clipboard Toggle word wrap

Configure IPsec VPN connections to establish encrypted tunnels over untrusted networks and ensure the integrity of data in transit. By using the RHEL system roles, you can automate the setup for use cases, such as connecting branch offices to headquarters.

Note

The vpn RHEL system role can only create VPN configurations that use pre-shared keys (PSKs) or certificates to authenticate peers to each other.

A host-to-host VPN establishes an encrypted connection between two devices, allowing applications to communicate safely over an insecure network. By using the vpn RHEL system role, you can automate the process of creating IPsec host-to-host connections.

For authentication, a pre-shared key (PSK) is a straightforward method that uses a single, shared secret known only to the two peers. This approach is simple to configure and ideal for basic setups where ease of deployment is a priority. However, you must keep the key strictly confidential. An attacker with access to the key can compromise the connection.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configuring VPN
  hosts: managed-node-01.example.com, managed-node-02.example.com
  tasks:
    - name: IPsec VPN with PSK authentication
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.vpn
      vars:
        vpn_connections:
          - hosts:
              managed-node-01.example.com:
              managed-node-02.example.com:
            auth_method: psk
            auto: start
        vpn_manage_firewall: true
        vpn_manage_selinux: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    hosts: <list>

    Defines a YAML dictionary with the peers between which you want to configure a VPN. If an entry is not an Ansible managed node, you must specify its fully-qualified domain name (FQDN) or IP address in the hostname parameter, for example: 

              ...
          - hosts:
              ...
              external-host.example.com:
                hostname: 192.0.2.1
    Copy to Clipboard Toggle word wrap

    The role configures the VPN connection on each managed node. The connections are named <peer_A>-to-<peer_B>, for example, managed-node-01.example.com-to-managed-node-02.example.com. Note that the role cannot configure Libreswan on external (unmanaged) nodes. You must manually create the configuration on these peers.

    auth_method: psk
    Enables PSK authentication between the peers. The role uses openssl on the control node to create the PSK.
    auto: <startup_method>
    Specifies the startup method of the connection. Valid values are add, ondemand, start, and ignore. For details, see the ipsec.conf(5) man page on a system with Libreswan installed. The default value of this variable is null, which means no automatic startup operation.
    vpn_manage_firewall: true
    Defines that the role opens the required ports in the firewalld service on the managed nodes.
    vpn_manage_selinux: true
    Defines that the role sets the required SELinux port type on the IPsec ports.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.vpn/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Confirm that the connections are successfully started, for example: 

    # ansible managed-node-01.example.com -m shell -a 'ipsec trafficstatus | grep "managed-node-01.example.com-to-managed-node-02.example.com"'
...
006 #3: "managed-node-01.example.com-to-managed-node-02.example.com", type=ESP, add_time=1741857153, inBytes=38622, outBytes=324626, maxBytes=2^63B, id='@managed-node-02.example.com'
    Copy to Clipboard Toggle word wrap

    Note that this command only succeeds if the VPN connection is active. If you set the auto variable in the playbook to a value other than start, you might need to manually activate the connection on the managed nodes first.

Use the vpn RHEL system role to automate the process of creating an IPsec host-to-host VPN. To enhance security by minimizing the risk of control messages being intercepted or disrupted, configure separate connections for both the data traffic and the control traffic.

A host-to-host VPN establishes a direct, secure, and encrypted connection between two devices, allowing applications to communicate safely over an insecure network, such as the internet.

For authentication, a pre-shared key (PSK) is a straightforward method that uses a single, shared secret known only to the two peers. This approach is simple to configure and ideal for basic setups where ease of deployment is a priority. However, you must keep the key strictly confidential. An attacker with access to the key can compromise the connection.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configuring VPN
  hosts: managed-node-01.example.com, managed-node-02.example.com
  tasks:
    - name: IPsec VPN with PSK authentication
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.vpn
      vars:
        vpn_connections:
          - name: control_plane_vpn
            hosts:
              managed-node-01.example.com:
                hostname: 203.0.113.1  # IP address for the control plane
              managed-node-02.example.com:
                hostname: 198.51.100.2 # IP address for the control plane
            auth_method: psk
            auto: start
          - name: data_plane_vpn
            hosts:
              managed-node-01.example.com:
                hostname: 10.0.0.1   # IP address for the data plane
              managed-node-02.example.com:
                hostname: 172.16.0.2 # IP address for the data plane
            auth_method: psk
            auto: start
        vpn_manage_firewall: true
        vpn_manage_selinux: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    hosts: <list>

    Defines a YAML dictionary with the hosts between which you want to configure a VPN. The connections are named <name>-<IP_address_A>-to-<IP_address_B>, for example control_plane_vpn-203.0.113.1-to-198.51.100.2.

    The role configures the VPN connection on each managed node. Note that the role cannot configure Libreswan on external (unmanaged) nodes. You must manually create the configuration on these hosts.

    auth_method: psk
    Enables PSK authentication between the hosts. The role uses openssl on the control node to create the pre-shared key.
    auto: <startup_method>
    Specifies the startup method of the connection. Valid values are add, ondemand, start, and ignore. For details, see the ipsec.conf(5) man page on a system with Libreswan installed. The default value of this variable is null, which means no automatic startup operation.
    vpn_manage_firewall: true
    Defines that the role opens the required ports in the firewalld service on the managed nodes.
    vpn_manage_selinux: true
    Defines that the role sets the required SELinux port type on the IPsec ports.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.vpn/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Confirm that the connections are successfully started, for example: 

    # ansible managed-node-01.example.com -m shell -a 'ipsec trafficstatus | grep "control_plane_vpn-203.0.113.1-to-198.51.100.2"'
...
006 #3: "control_plane_vpn-203.0.113.1-to-198.51.100.2", type=ESP, add_time=1741860073, inBytes=0, outBytes=0, maxBytes=2^63B, id='198.51.100.2'
    Copy to Clipboard Toggle word wrap

    Note that this command only succeeds if the VPN connection is active. If you set the auto variable in the playbook to a value other than start, you might need to manually activate the connection on the managed nodes first.

A site-to-site VPN establishes an encrypted tunnel between two distinct networks, seamlessly linking them across an insecure public network. By using the vpn RHEL system role, you can automate the process of creating IPsec site-to-site VPN connections.

A site-to-site VPN enables devices in a branch office to access resources at a corporate headquarters just as if they were all part of the same local network.

For authentication, a pre-shared key (PSK) is a straightforward method that uses a single, shared secret known only to the two peers. This approach is simple to configure and ideal for basic setups where ease of deployment is a priority. However, you must keep the key strictly confidential. An attacker with access to the key can compromise the connection.

Prerequisites

Procedure

  1. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Configuring VPN
  hosts: managed-node-01.example.com, managed-node-02.example.com
  tasks:
    - name: IPsec VPN with PSK authentication
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.vpn
      vars:
        vpn_connections:
          - hosts:
              managed-node-01.example.com:
                subnets:
                  - 192.0.2.0/24
              managed-node-02.example.com:
                subnets:
                  - 198.51.100.0/24
                  - 203.0.113.0/24
            auth_method: psk
            auto: start
        vpn_manage_firewall: true
        vpn_manage_selinux: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    hosts: <list>

    Defines a YAML dictionary with the gateways between which you want to configure a VPN. If an entry is not an Ansible-managed node, you must specify its fully-qualified domain name (FQDN) or IP address in the hostname parameter, for example: 

              ...
          - hosts:
              ...
              external-host.example.com:
                hostname: 192.0.2.1
    Copy to Clipboard Toggle word wrap

    The role configures the VPN connection on each managed node. The connections are named <gateway_A>-to-<gateway_B>, for example, managed-node-01.example.com-to-managed-node-02.example.com. Note that the role cannot configure Libreswan on external (unmanaged) nodes. You must manually create the configuration on these peers.

    subnets: <yaml_list_of_subnets>
    Defines subnets in classless inter-domain routing (CIDR) format that are connected through the tunnel.
    auth_method: psk
    Enables PSK authentication between the peers. The role uses openssl on the control node to create the PSK.
    auto: <startup_method>
    Specifies the startup method of the connection. Valid values are add, ondemand, start, and ignore. For details, see the ipsec.conf(5) man page on a system with Libreswan installed. The default value of this variable is null, which means no automatic startup operation.
    vpn_manage_firewall: true
    Defines that the role opens the required ports in the firewalld service on the managed nodes.
    vpn_manage_selinux: true
    Defines that the role sets the required SELinux port type on the IPsec ports.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.vpn/README.md file on the control node.

  2. Validate the playbook syntax: 

    $ ansible-playbook --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook: 

    $ ansible-playbook ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • Confirm that the connections are successfully started, for example: 

    # ansible managed-node-01.example.com -m shell -a 'ipsec trafficstatus | grep "managed-node-01.example.com-to-managed-node-02.example.com"'
...
006 #3: "managed-node-01.example.com-to-managed-node-02.example.com", type=ESP, add_time=1741857153, inBytes=38622, outBytes=324626, maxBytes=2^63B, id='@managed-node-02.example.com'
    Copy to Clipboard Toggle word wrap

    Note that this command only succeeds if the VPN connection is active. If you set the auto variable in the playbook to a value other than start, you might need to manually activate the connection on the managed nodes first.

An IPsec mesh creates a fully interconnected network where every server can communicate securely and directly with every other server. By using the vpn RHEL system role, you can automate configuring a VPN mesh with certificate-based authentication among managed nodes.

An IPsec mesh is ideal for distributed database clusters or high-availability environments that span multiple data centers or cloud providers. Establishing a direct, encrypted tunnel between each pair of servers ensures secure communication without a central bottleneck.

For authentication, using digital certificates managed by a Certificate Authority (CA) offers a highly secure and scalable solution. Each host in the mesh presents a certificate signed by a trusted CA. This method provides strong, verifiable authentication and simplifies user management. Access can be granted or revoked centrally at the CA, and Libreswan enforces this by checking each certificate against a certificate revocation list (CRL), denying access if a certificate appears on the list.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.

  • You prepared a PKCS #12 file for each managed node:

    • Each file contains:

      • The private key of the server
      • The server certificate
      • The CA certificate
      • If required, intermediate certificates
    • The files are named <managed_node_name_as_in_the_inventory>.p12.
    • The files are stored in the same directory as the playbook.

    • The server certificate contains the following fields:

      • Extended Key Usage (EKU) is set to TLS Web Server Authentication.
      • Common Name (CN) or Subject Alternative Name (SAN) is set to the fully-qualified domain name (FQDN) of the host.
      • X509v3 CRL distribution points contains URLs to Certificate Revocation Lists (CRLs).

Procedure

  1. Edit the ~/inventory file, and append the cert_name variable: 

    managed-node-01.example.com cert_name=managed-node-01.example.com
managed-node-02.example.com cert_name=managed-node-02.example.com
managed-node-03.example.com cert_name=managed-node-03.example.com
    Copy to Clipboard Toggle word wrap

    Set the cert_name variable to the value of the common name (CN) field used in the certificate for each host. Typically, the CN field is set to the fully-qualified domain name (FQDN).

  2. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      pkcs12_pwd: <password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  3. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    - name: Configuring VPN
  hosts: managed-node-01.example.com, managed-node-02.example.com, managed-node-03.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: Install LibreSwan
      ansible.builtin.package:
        name: libreswan
        state: present

    - name: Identify the path to IPsec NSS database
      ansible.builtin.set_fact:
        nss_db_dir: "{{ '/etc/ipsec.d/' if
          ansible_distribution in ['CentOS', 'RedHat']
          and ansible_distribution_major_version is version('8', '=')
          else '/var/lib/ipsec/nss/' }}"

    - name: Locate IPsec NSS database files
      ansible.builtin.find:
        paths: "{{ nss_db_dir }}"
        patterns: "*.db"
      register: db_files

    - name: Initialize IPsec NSS database if not initialized
      ansible.builtin.command:
        cmd: ipsec initnss
      when: db_files.matched == 0

    - name: Copy PKCS #12 file to the managed node
      ansible.builtin.copy:
        src: "~/{{ inventory_hostname }}.p12"
        dest: "/etc/ipsec.d/{{ inventory_hostname }}.p12"
        mode: 0600

    - name: Import PKCS #12 file in IPsec NSS database
      ansible.builtin.shell:
        cmd: 'pk12util -d {{ nss_db_dir }} -i /etc/ipsec.d/{{ inventory_hostname }}.p12 -W "{{ pkcs12_pwd }}"'

    - name: Remove PKCS #12 file
      ansible.builtin.file:
        path: "/etc/ipsec.d/{{ inventory_hostname }}.p12"
        state: absent

    - name: Opportunistic mesh IPsec VPN with certificate-based authentication
      ansible.builtin.include_role:
        name: redhat.rhel_system_roles.vpn
      vars:
        vpn_connections:
          - opportunistic: true
            auth_method: cert
            policies:
              - policy: private
                cidr: default
              - policy: private
                cidr: 192.0.2.0/24
              - policy: clear
                cidr: 192.0.2.1/32
        vpn_manage_firewall: true
        vpn_manage_selinux: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    opportunistic: true
    Enables an opportunistic mesh among multiple hosts. The policies variable defines for which subnets and hosts traffic must or can be encrypted and which of them should continue using plain text connections.
    auth_method: cert
    Enables certificate-based authentication. This requires that you specify the nickname of each managed node’s certificate in the inventory.
    policies: <list_of_policies>

    Defines the Libreswan policies in YAML list format.

    The default policy is private-or-clear. To change it to private, the above playbook contains an according policy for the default cidr entry.

    To prevent a loss of the SSH connection during the execution of the playbook if the Ansible control node is in the same IP subnet as the managed nodes, add a clear policy for the control node’s IP address. For example, if the mesh should be configured for the 192.0.2.0/24 subnet and the control node uses the IP address 192.0.2.1, you require a clear policy for 192.0.2.1/32 as shown in the playbook.

    For details about policies, see the ipsec.conf(5) man page on a system with Libreswan installed.

    vpn_manage_firewall: true
    Defines that the role opens the required ports in the firewalld service on the managed nodes.
    vpn_manage_selinux: true
    Defines that the role sets the required SELinux port type on the IPsec ports.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/rhel-system-roles.vpn/README.md file on the control node.

  4. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  5. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. On a node in the mesh, ping another node to activate the connection: 

    [root@managed-node-01]# ping managed-node-02.example.com
    Copy to Clipboard Toggle word wrap

  2. Confirm that the connection is active: 

    [root@managed-node-01]# ipsec trafficstatus
006 #2: "private#192.0.2.0/24"[1] ...192.0.2.2, type=ESP, add_time=1741938929, inBytes=372408, outBytes=545728, maxBytes=2^63B, id='CN=managed-node-02.example.com'
    Copy to Clipboard Toggle word wrap

You can use the microsoft.sql.server Ansible system role to automate the installation and management of Microsoft SQL Server. This role also optimizes Red Hat Enterprise Linux (RHEL) to improve the performance and throughput of SQL Server by applying the mssql TuneD profile.

Note

During the installation, the role adds repositories for SQL Server and related packages to the managed hosts. Packages in these repositories are provided, maintained, and hosted by Microsoft.

By using the microsoft.sql.server Ansible system role, you can automate the installation and configuration of Microsoft SQL Server with TLS encryption. In the playbook, you can use an existing private key and a TLS certificate that was issued by a certificate authority (CA).

If your application requires a Microsoft SQL Server database, you can configure SQL Server with TLS encryption to enable secure communication between the application and the database. The microsoft.sql.server role uses the certificate Ansible system role to configure certmonger and request a certificate from IdM.

Depending on the RHEL version on the managed host, the version of SQL Server that you can install differs:

  • RHEL 7.9: SQL Server 2017 and 2019
  • RHEL 8: SQL Server 2017, 2019, and 2022
  • RHEL 9.4 and later: SQL Server 2022

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • You installed the ansible-collection-microsoft-sql package or the microsoft.sql collection on the control node.
  • The managed node has 2 GB or more RAM installed.
  • The managed node uses one of the following versions: RHEL 7.9, RHEL 8, RHEL 9.4 or later.
  • You stored the certificate in the sql_crt.pem file in the same directory as the playbook.
  • You stored the private key in the sql_cert.key file in the same directory as the playbook.
  • SQL clients trust the CA that issued the certificate.

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      sa_pwd: <sa_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Installing and configuring Microsoft SQL Server
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: SQL Server with an existing private key and certificate
      ansible.builtin.include_role:
        name: microsoft.sql.server
      vars:
        mssql_accept_microsoft_odbc_driver_for_sql_server_eula: true
        mssql_accept_microsoft_cli_utilities_for_sql_server_eula: true
        mssql_accept_microsoft_sql_server_standard_eula: true

        mssql_version: 2022
        mssql_password: "{{ sa_pwd  }}"
        mssql_edition: Developer
        mssql_tcp_port: 1433
        mssql_manage_firewall: true

        mssql_tls_enable: true
        mssql_tls_self_sign: false
        mssql_tls_cert: sql_crt.pem
        mssql_tls_private_key: sql_cert.key
        mssql_tls_version: 1.2
        mssql_tls_force: true
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    mssql_tls_enable: true
    Enables TLS encryption. If you enable this setting, you must also define mssql_tls_cert and mssql_tls_private_key.
    mssql_tls_self_sign: false
    Indicates whether the certificates that you use are self-signed or not. Based on this setting, the role decides whether to run the sqlcmd command with the -C argument to trust certificates.
    mssql_tls_cert: <path>
    Sets the path to the TLS certificate stored on the control node. The role copies this file to the /etc/pki/tls/certs/ directory on the managed node.
    mssql_tls_private_key: <path>
    Sets the path to the TLS private key on the control node. The role copies this file to the /etc/pki/tls/private/ directory on the managed node.
    mssql_tls_force: true
    Replaces the TLS certificate and private key in their destination directories if they exist.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/microsoft.sql-server/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • On the SQL Server host, use the sqlcmd utility with the -N parameter to establish an encrypted connection to SQL server and run a query, for example: 

    $ /opt/mssql-tools/bin/sqlcmd -N -S server.example.com -U "sa" -P <sa_password> -Q 'SELECT SYSTEM_USER'
    Copy to Clipboard Toggle word wrap

    If the command succeeds, the connection to the server was TLS encrypted.

By using the microsoft.sql.server Ansible system role, you can automate the installation and configuration of Microsoft SQL Server with TLS encryption.

If your application requires a Microsoft SQL Server database, you can configure SQL Server with TLS encryption to enable secure communication between the application and the database. If the SQL Server host is a member in a RHEL Identity Management (IdM) domain, the certmonger service can manage the certificate request and future renewals.

The microsoft.sql.server role uses the certificate Ansible system role to configure certmonger and request a certificate from IdM.

Depending on the RHEL version on the managed host, the version of SQL Server that you can install differs:

  • RHEL 7.9: SQL Server 2017 and 2019
  • RHEL 8: SQL Server 2017, 2019, and 2022
  • RHEL 9.4 and later: SQL Server 2022

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • You installed the ansible-collection-microsoft-sql package or the microsoft.sql collection on the control node.
  • The managed node has 2 GB or more RAM installed.
  • The managed node uses one of the following versions: RHEL 7.9, RHEL 8, RHEL 9.4 or later.
  • You enrolled the managed node in a Red Hat Enterprise Linux Identity Management (IdM) domain.

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      sa_pwd: <sa_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Installing and configuring Microsoft SQL Server
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: SQL Server with certificates issued by Red Hat IdM
      ansible.builtin.include_role:
        name: microsoft.sql.server
      vars:
        mssql_accept_microsoft_odbc_driver_for_sql_server_eula: true
        mssql_accept_microsoft_cli_utilities_for_sql_server_eula: true
        mssql_accept_microsoft_sql_server_standard_eula: true

        mssql_version: 2022
        mssql_password: "{{ sa_pwd  }}"
        mssql_edition: Developer
        mssql_tcp_port: 1433
        mssql_manage_firewall: true

        mssql_tls_enable: true
        mssql_tls_certificates:
          - name: sql_cert
            dns: server.example.com
            ca: ipa
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    mssql_tls_enable: true
    Enables TLS encryption. If you enable this setting, you must also define mssql_tls_certificates.
    mssql_tls_certificates
    A list of YAML dictionaries with settings for the certificate role.
    name: <file_name>
    Defines the base name of the certificate and private key. The certificate role stores the certificate in the /etc/pki/tls/certs/<file_name>.crt and the private key in the /etc/pki/tls/private/<file_name>.key file.
    dns: <hostname_or_list_of_hostnames>
    Sets the hostnames that the Subject Alternative Names (SAN) field in the issued certificate contains. You can use a wildcard (*) or specify multiple names in YAML list format.
    ca: <ca_type>
    Defines how the certificate role requests the certificate. Set the variable to ipa if the host is enrolled in an IdM domain or self-sign to request a self-signed certificate.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/microsoft.sql-server/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  • On the SQL Server host, use the sqlcmd utility with the -N parameter to establish an encrypted connection to SQL server and run a query, for example: 

    $ /opt/mssql-tools/bin/sqlcmd -N -S server.example.com -U "sa" -P <sa_password> -Q 'SELECT SYSTEM_USER'
    Copy to Clipboard Toggle word wrap

    If the command succeeds, the connection to the server was TLS encrypted.

When you use the microsoft.sql.server Ansible system role to install and configure a new SQL Server, you can customize the paths and modes of the data and log directories. For example, configure custom paths if you want to store databases and log files in a different directory with more storage.

Important

If you change the data or log path and re-run the playbook, the previously-used directories and all their content remains at the original path. Only new databases and logs are stored in the new location.

Expand
Table 32.1. SQL Server default settings for data and log directories
TypeDirectoryModeOwnerGroup

Data

/var/opt/mssql/data/

[a]

mssql

mssql

Logs

/var/opt/mssql/los/

[a]

mssql

mssql

[a] If the directory exists, the role preserves the mode. If the directory does not exist, the role applies the default umask on the managed node when it creates the directory.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • You installed the ansible-collection-microsoft-sql package or the microsoft.sql collection on the control node.
  • The managed node has 2 GB or more RAM installed.
  • The managed node uses one of the following versions: RHEL 7.9, RHEL 8, RHEL 9.4 or later.

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      sa_pwd: <sa_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Edit an existing playbook file, for example ~/playbook.yml, and add the storage and log-related variables: 

    ---
- name: Installing and configuring Microsoft SQL Server
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: SQL Server with custom storage paths
      ansible.builtin.include_role:
        name: microsoft.sql.server
      vars:
        mssql_accept_microsoft_odbc_driver_for_sql_server_eula: true
        mssql_accept_microsoft_cli_utilities_for_sql_server_eula: true
        mssql_accept_microsoft_sql_server_standard_eula: true

        mssql_version: 2022
        mssql_password: "{{ sa_pwd  }}"
        mssql_edition: Developer
        mssql_tcp_port: 1433
        mssql_manage_firewall: true

        mssql_datadir: /var/lib/mssql/
        mssql_datadir_mode: '0700'
        mssql_logdir: /var/log/mssql/
        mssql_logdir_mode: '0700'
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    mssql_datadir_mode and mssql_logdir_mode
    Set the permission modes. Specify the value in single quotes to ensure that the role parses the value as a string and not as an octal number.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/microsoft.sql-server/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

Verification

  1. Display the mode of the data directory: 

    $ ansible managed-node-01.example.com -m command -a 'ls -ld /var/lib/mssql/'
drwx------. 12 mssql mssql 4096 Jul  3 13:53 /var/lib/mssql/
    Copy to Clipboard Toggle word wrap

  2. Display the mode of the log directory: 

    $ ansible managed-node-01.example.com -m command -a 'ls -ld /var/log/mssql/'
drwx------. 12 mssql mssql 4096 Jul  3 13:53 /var/log/mssql/
    Copy to Clipboard Toggle word wrap

You can integrate Microsoft SQL Server into an Active Directory (AD) to enable AD users to authenticate to SQL Server. By using the microsoft.sql.server Ansible system role, you can automate this process and remotely install and configure SQL Server accordingly.

Depending on the RHEL version on the managed host, the version of SQL Server that you can install differs:

  • RHEL 7.9: SQL Server 2017 and 2019
  • RHEL 8: SQL Server 2017, 2019, and 2022
  • RHEL 9.4 and later: SQL Server 2022

Note that you must still perform manual steps in AD and SQL Server after you run the playbook.

Prerequisites

  • You have prepared the control node and the managed nodes.
  • You are logged in to the control node as a user who can run playbooks on the managed nodes.
  • The account you use to connect to the managed nodes has sudo permissions on them.
  • You installed the ansible-collection-microsoft-sql package or the microsoft.sql collection on the control node.
  • The managed node has 2 GB or more RAM installed.
  • The managed node uses one of the following versions: RHEL 7.9, RHEL 8, RHEL 9.4 or later.
  • An AD domain is available in the network.
  • A reverse DNS (RDNS) zone exists in AD, and it contains Pointer (PTR) resource records for each AD domain controller (DC).
  • The managed host’s network settings use an AD DNS server.

  • The managed host can resolve the following DNS entries:

    • Both the hostnames and the fully-qualified domain names (FQDNs) of the AD DCs resolve to their IP addresses.
    • The IP addresses of the AD DCs resolve to their FQDNs.

Procedure

  1. Store your sensitive variables in an encrypted file:

    1. Create the vault: 

      $ ansible-vault create ~/vault.yml
New Vault password: <vault_password>
Confirm New Vault password: <vault_password>
      Copy to Clipboard Toggle word wrap

    2. After the ansible-vault create command opens an editor, enter the sensitive data in the <key>: <value> format: 

      sa_pwd: <sa_password>
sql_pwd: <SQL_AD_password>
ad_admin_pwd: <AD_admin_password>
      Copy to Clipboard Toggle word wrap
    3. Save the changes, and close the editor. Ansible encrypts the data in the vault.

  2. Create a playbook file, for example, ~/playbook.yml, with the following content: 

    ---
- name: Installing and configuring Microsoft SQL Server
  hosts: managed-node-01.example.com
  vars_files:
    - ~/vault.yml
  tasks:
    - name: SQL Server with AD authentication
      ansible.builtin.include_role:
        name: microsoft.sql.server
      vars:
        mssql_accept_microsoft_odbc_driver_for_sql_server_eula: true
        mssql_accept_microsoft_cli_utilities_for_sql_server_eula: true
        mssql_accept_microsoft_sql_server_standard_eula: true

        mssql_version: 2022
        mssql_password: "{{ sa_pwd }}"
        mssql_edition: Developer
        mssql_tcp_port: 1433
        mssql_manage_firewall: true

        mssql_ad_configure: true
        mssql_ad_join: true
        mssql_ad_sql_user: sqluser
        mssql_ad_sql_password: "{{ sql_pwd }}"
        ad_integration_realm: ad.example.com
        ad_integration_user: Administrator
        ad_integration_password: "{{ ad_admin_pwd }}"
    Copy to Clipboard Toggle word wrap

    The settings specified in the example playbook include the following:

    mssql_ad_configure: true
    Enables authentication against AD.
    mssql_ad_join: true
    Uses the ad_integration RHEL system role to join the managed node to AD. The role uses the settings from the ad_integration_realm, ad_integration_user, and ad_integration_password variables to join the domain.
    mssql_ad_sql_user: <username>
    Sets the name of an AD account that the role should create in AD and SQL Server for administration purposes.
    ad_integration_user: <AD_user>
    Sets the name of an AD user with privileges to join machines to the domain and to create the AD user specified in mssql_ad_sql_user.

    For details about all variables used in the playbook, see the /usr/share/ansible/roles/microsoft.sql-server/README.md file on the control node.

  3. Validate the playbook syntax: 

    $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook.yml
    Copy to Clipboard Toggle word wrap

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  4. Run the playbook: 

    $ ansible-playbook --ask-vault-pass ~/playbook.yml
    Copy to Clipboard Toggle word wrap

  5. Authorize AD users that should be able to authenticate to SQL Server. On the SQL Server, perform the following steps:

    1. Obtain a Kerberos ticket for the Administrator user: 

      $ kinit Administrator@ad.example.com
      Copy to Clipboard Toggle word wrap

    2. Authorize an AD user: 

      $ /opt/mssql-tools/bin/sqlcmd -S. -Q 'CREATE LOGIN [AD\<AD_user>] FROM WINDOWS;'
      Copy to Clipboard Toggle word wrap

      Repeat this step for every AD user who should be able to access SQL Server.

Verification

  • On the managed node that runs SQL Server:

    1. Obtain a Kerberos ticket for an AD user: 

      $ kinit <AD_user>@ad.example.com
      Copy to Clipboard Toggle word wrap

    2. Use the sqlcmd utility to log in to SQL Server and run a query, for example: 

      $ /opt/mssql-tools/bin/sqlcmd -S. -Q 'SELECT SYSTEM_USER'
      Copy to Clipboard Toggle word wrap

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