Support removing cinder-backup from pcmk control

TripleO traditionally deploys the cinder-backup service to run
A/P (active/passive) under pacemaker, but cinder itself supports
running A/A. This patch adds deploy_steps_tasks to remove the
service from pcmk control (essentially deleting the pcs resource)
prior to deploying it as a regular containerized (non-pcmk) service.

A new cinder-backup-active-active.yaml environment file helps the
user clarify their intent. The legacy cinder-backup.yaml file
continues to deploy the service under pacemaker (to preserve the
default deployment behavior), but rather than encouraging users to
edit the file to switch deployment modes (as a comment in the file
used to advise), users can proactively deploy the A/A mode (or switch
from A/P to A/A) by including the new environment file.

Change-Id: Ic94025f51083da77f4ba6ee934ebcf32bcb9909f

deployment/cinder/cinder-backup-container-puppet.yaml

@@ -215,6 +215,38 @@ outputs:
                 name: virt_sandbox_use_netlink
                 persistent: yes
                 state: yes
+      deploy_steps_tasks:
+        - name: Clean up when switching cinder-backup from pcmk to active-active
+          when:
+            - step|int == 1
+          become: true
+          block:
+            - name: Check if cinder-backup is running under pacemaker
+              command: "pcs status"
+              register: cinder_backup_pcs_status
+              check_mode: false
+              failed_when: false
+              changed_when: false
+
+            - when:
+              - '"cinder-backup" in cinder_backup_pcs_status.stdout'
+              block:
+                - name: Remove the openstack-cinder-backup pcs resource
+                  pacemaker_resource:
+                    resource: openstack-cinder-backup
+                    state: delete
+                  run_once: true
+
+                - name: Identify the cinder-backup pcmklatest container image
+                  shell: "{{container_cli}} images | awk '$1 ~ \"cinder-backup\" && $2 == \"pcmklatest\" {print $1\":\"$2}'"
+                  register: cinder_backup_pcmklatest_image
+                  check_mode: false
+                  changed_when: false
+
+                - name: Remove the cinder-backup pcmklatest container image
+                  command: "{{container_cli}} rmi {{cinder_backup_pcmklatest_image.stdout}}"
+                  when:
+                    - cinder_backup_pcmklatest_image.stdout|length > 0
       external_upgrade_tasks:
         - when:
             - step|int == 1

environments/cinder-backup-active-active.yaml

@@ -0,0 +1,2 @@
+resource_registry:
+  OS::TripleO::Services::CinderBackup: ../deployment/cinder/cinder-backup-container-puppet.yaml

environments/cinder-backup.yaml

@@ -1,4 +1,3 @@
 resource_registry:
   OS::TripleO::Services::CinderBackup: ../deployment/cinder/cinder-backup-pacemaker-puppet.yaml
-  # For non-pcmk managed implementation
-  # OS::TripleO::Services::CinderBackup: ../deployment/cinder/cinder-backup-container-puppet.yaml
+  # Use cinder-backup-active-active.yaml for non-pcmk managed implementation

releasenotes/notes/cinder-backup-active-active-2eb8f8cf612a7989.yaml

@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    The Cinder Backup service can be switched from running active/passive
+    under pacemaker, to active-active mode where it runs simultaneously on
+    every node on which it's deployed. Note that the service will be restarted
+    when switching modes, which will interrupt any backup operations currently
+    in progress.