11.15. Configuring a high availability cluster with a quorum device by using RHEL system roles

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>

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

      cluster_password: <cluster_password>

   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

   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.

   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-qdevice.yml

   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

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

   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.

   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.

2. Validate the playbook syntax:

   $ ansible-playbook --ask-vault-pass --syntax-check ~/playbook-cluster-qdevice.yml

   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