Chapter 19. Managing capacity with Instances

1. You require a Red Hat Enterprise Linux operating system. Each node in the mesh requires a static IP address, or a resolvable DNS hostname that Ansible Automation Platform can access.
2. Ensure that you have the minimum requirements for the RHEL virtual machine before proceeding. For more information, see the System requirements.

3. Deploy the RHEL instances within the remote networks where communication is required. For information about creating virtual machines, see Creating Virtual Machines in the Red Hat Enterprise Linux documentation. Remember to scale the capacity of your virtual machines sufficiently so that your proposed tasks can run on them.

   • RHEL ISOs can be obtained from access.redhat.com.
   • RHEL cloud images can be built using Image Builder from console.redhat.com.

Procedure

1. Create a secret:

   oc create secret generic ee-pull-secret \
        --from-literal=username=<username> \
        --from-literal=password=<password> \
        --from-literal=url=registry.redhat.io
   
   
   oc edit automationcontrollers <instance name>

2. Add ee_pull_credentials_secret ee-pull-secret to the specification:

   spec.ee_pull_credentials_secret=ee-pull-secret

Procedure

1. SSH into each of the RHEL instances and perform the following steps. Depending on your network access and controls, SSH proxies or other access models might be required.

   Use the following command:

   ssh [username]@[host_ip_address]

   For example, for an Ansible Automation Platform instance running on Amazon Web Services.

   ssh ec2-user@10.0.0.6

2. Create or copy an SSH key that can be used to connect from the hop node to the execution node in later steps. This can be a temporary key used just for the automation mesh configuration, or a long-lived key. The SSH user and key are used in later steps.

3. Enable your RHEL subscription with baseos and appstream repositories. Ansible Automation Platform RPM repositories are only available through subscription-manager, not the Red Hat Update Infrastructure (RHUI). If you attempt to use any other Linux footprint, including RHEL with RHUI, this causes errors.

   sudo subscription-manager register --auto-attach

   If Simple Content Access is enabled for your account, use:

   sudo subscription-manager register

   For more information about Simple Content Access, see Getting started with simple content access.

4. Enable Ansible Automation Platform subscriptions and the proper Red Hat Ansible Automation Platform channel:

   For RHEL 8

   # subscription-manager repos --enable ansible-automation-platform-2.5-for-rhel-8-x86_64-rpms

   For RHEL 9

   # subscription-manager repos --enable ansible-automation-platform-2.5-for-rhel-9-x86_64-rpms

   For ARM

   # subscription-manager repos --enable ansible-automation-platform-2.5-for-rhel-aarch64-rpms

5. Ensure the packages are up to date:

   sudo dnf upgrade -y

6. Install the ansible-core packages on the machine where the downloaded bundle is to run:

   sudo dnf install -y ansible-core

   Note

   Ansible core is required on the machine that runs the automation mesh configuration bundle playbooks. This document assumes that happens on the execution node. However, this step can be omitted if you run the playbook from a different machine. You cannot run directly from the control node, this is not currently supported, but future support expects that the control node has direct connectivity to the execution node.

Procedure

1. From the navigation panel, select Automation Execution Infrastructure Instances.

2. On the Instances list page, click Add instance. The Add Instance window opens.

   

   An instance requires the following attributes:

   • Host name: (required) Enter a fully qualified domain name (public DNS) or IP address for your instance. This field is equivalent to hostname for installer-based deployments.

     Note

     If the instance uses private DNS that cannot be resolved from the control cluster, DNS lookup routing fails, and the generated SSL certificates is invalid. Use the IP address instead.

   • Optional: Description: Enter a description for the instance.
   • Instance state: This field is auto-populated, indicating that it is being installed, and cannot be modified.
   • Listener port: This port is used for the receptor to listen on for incoming connections. You can set the port to one that is appropriate for your configuration. This field is equivalent to listener_port in the API. The default value is 27199, though you can set your own port value.

   • Instance type: Only execution and hop nodes can be created. Operator based deployments do not support Control or Hybrid nodes.

     Options:

     • Enable instance: Check this box to make it available for jobs to run on an execution node.
     • Check the Managed by policy box to enable policy to dictate how the instance is assigned.

     • Peers from control nodes:

       • If you are configuring a hop node:

         • If the hop node needs to have requests pushed directly from automation controller, then check the Peers from Control box.
         • If the hop node is peered to another hop node, then make sure Peers from Control is not checked.

       • If you are configuring an execution node:

         • If the execution node needs to have requests pushed directly from automation controller, then check the Peers from Control box.
         • If the execution node is peered to a hop node, then make sure that Peers from Control is not checked.
3. Click Associate peers.

4. To view a graphical representation of your updated topology, see Topology view.

   Note

   Execute the following steps from any computer that has SSH access to the newly created instance.

5. Click the icon next to Download Bundle to download the tar file that includes this new instance and the files necessary to install the created node into the automation mesh.

   The install bundle contains TLS certificates and keys, a certificate authority, and a proper Receptor configuration file.

   receptor-ca.crt
   work-public-key.pem
   receptor.key
   install_receptor.yml
   inventory.yml
   group_vars/all.yml
   requirements.yml

6. Extract the downloaded tar.gz Install Bundle from the location where you downloaded it. To ensure that these files are in the correct location on the remote machine, the install bundle includes the install_receptor.yml playbook.

7. Before running the ansible-playbook command, edit the following fields in the inventory.yml file:

   all:
     hosts:
       remote-execution:
         ansible_host: localhost # change to the mesh node host name
             ansible_user: <username> # user provided
             ansible_ssh_private_key_file: ~/.ssh/<id_rsa>

   • Ensure ansible_host is set to the IP address or DNS of the node.
   • Set ansible_user to the username running the installation.
   • Set ansible_ssh_private_key_file to contain the filename of the private key used to connect to the instance.
   • The content of the inventory.yml file serves as a template and contains variables for roles that are applied during the installation and configuration of a receptor node in a mesh topology. You can modify some of the other fields, or replace the file in its entirety for advanced scenarios. For more information, see Role Variables.

8. For a node that uses a private DNS, add the following line to inventory.yml:

    ansible_ssh_common_args: <your ssh ProxyCommand setting>

   This instructs the install-receptor.yml playbook to use the proxy command to connect through the local DNS node to the private node.

9. When the attributes are configured, click Save. The Details page of the created instance opens.
10. Save the file to continue.

11. The system that is going to run the install bundle to setup the remote node and run ansible-playbook requires the ansible.receptor collection to be installed:

    ansible-galaxy collection install ansible.receptor

    or

    ansible-galaxy install -r requirements.yml

    • Installing the receptor collection dependency from the requirements.yml file consistently retrieves the receptor version specified there. Additionally, it retrieves any other collection dependencies that might be needed in the future.
    • Install the receptor collection on all nodes where your playbook will run, otherwise an error occurs.

12. If receptor_listener_port is defined, the machine also requires an available open port on which to establish inbound TCP connections, for example, 27199. Run the following command to open port 27199 for receptor communication (Make sure you have port 27199 open in your firewall):

    sudo firewall-cmd --permanent --zone=public --add-port=27199/tcp

    Note

    It might be the case that some servers do not listen on receptor port (the default is 27199)

    Suppose you have a Control plane with nodes A, B, C, D

    The RPM installer creates a strongly connected peering between the control plane nodes with a least privileged approach and opens the tcp listener only on those nodes where it is required. All the receptor connections are bidirectional, so once the connection is created, the receptor can communicate in both directions.

    The following is an example peering set up for three controller nodes:

    Controller node A -→ Controller node B

    Controller node A -→ Controller node C

    Controller node B -→ Controller node C

    You can force the listener by setting

    receptor_listener=True

    However, a connection Controller B -→ A is likely to be rejected as that connection already exists.

    This means that nothing connects to Controller A as Controller A is creating the connections to the other nodes, and the following command does not return anything on Controller A:

    [root@controller1 ~]# ss -ntlp | grep 27199 [root@controller1 ~]#

13. Run the following playbook on the machine where you want to update your automation mesh:

    ansible-playbook -i inventory.yml install_receptor.yml