11.14. Configuring alerts for a high availability cluster by using the ha_cluster RHEL system role

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: 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

   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

   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