11.5. Configuring a high availability cluster with resource and resource operation defaults

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.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

   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

   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