Make execution of the backup idempotent

Currently, the playbook stops the services and the pacemaker to perform the backup. If the backup fails for whatever reason, the playbook cannot run again and fails due to the services being down. This patch fixes the issue in two directions. First, by using the block-always ansible feature, we ensure that whenever an error happens, the playbook will restart the pacemaker and the services before exiting.

The second direction is on the execution itself. By controlling certain actions, we ensure that the backup will be succesful not matter what state the services and the pacemaker are when the playbook is ran. This ensures success even in the case an operator stops the ansible execution manually (which will not trigger the 'always' condition).

BZ: #1954818
Change-Id: Id2aff61f219b0c4992f6f0045f1aba2c7d129758
(cherry picked from commit 9a865d1769)

tripleo_ansible/roles/backup_and_restore/tasks/ceph_authentication.yml

@@ -32,6 +32,12 @@
   tags:
     - always
 
+- name: Unpause ceph mon container if paused
+  command: "{{ tripleo_container_cli }} unpause ceph-mon-{{ ansible_facts['hostname'] }}"
+  failed_when: false
+  tags:
+    - bar_create_recover_image
+
 - name: Export ceph authentication
   shell: |
     set -o pipefail

tripleo_ansible/roles/backup_and_restore/tasks/db_backup.yml

@@ -48,6 +48,31 @@
   tags:
     - bar_create_recover_image
 
+- name: Enable pacemaker if it is stopped
+  command: pcs cluster start --all
+  when:
+    - enabled_galera
+    - tripleo_backup_and_restore_service_manager|bool
+    - not tripleo_backup_and_restore_enable_snapshots|bool
+  run_once: true
+  tags:
+    - bar_create_recover_image
+
+- name: Wait until pacemaker has Galera up&running
+  shell: |
+    set -o pipefail
+    ss -tunlp | grep ":3306 " | sed -e 's/.*\///'
+  register: mysql_result
+  retries: 300
+  until: mysql_result is search('mysqld')
+  delay: 5
+  when:
+    - enabled_galera
+    - tripleo_backup_and_restore_service_manager|bool
+    - not tripleo_backup_and_restore_enable_snapshots|bool
+  tags:
+    - bar_create_recover_image
+
 - name: Get the mysql container id when galera is enabled
   shell: |
     set -o pipefail
@@ -65,6 +90,17 @@
   tags:
     - bar_create_recover_image
 
+- name: Unpause mysql for backup if it is paused
+  command: "{{ tripleo_container_cli }} unpause {{ tripleo_backup_and_restore_mysql_container }}"
+  when:
+    - mysql_password.stderr is defined
+    - tripleo_backup_and_restore_mysql_container == "mysql"
+    - not enabled_galera
+    - tripleo_backup_and_restore_service_manager|bool
+  failed_when: false
+  tags:
+    - bar_create_recover_image
+
 - name: MySQL Grants backup
   shell: |
     set -o pipefail
@@ -98,7 +134,8 @@
     - tripleo_backup_and_restore_mysql_container == "mysql"
     - not enabled_galera
     - tripleo_backup_and_restore_service_manager|bool
-    - not tripleo_backup_and_restore_enable_snapshots
+    - not tripleo_backup_and_restore_enable_snapshots|bool
+  failed_when: false
   tags:
     - bar_create_recover_image
 
@@ -107,7 +144,7 @@
   when:
     - enabled_galera
     - tripleo_backup_and_restore_service_manager|bool
-    - not tripleo_backup_and_restore_enable_snapshots
+    - not tripleo_backup_and_restore_enable_snapshots|bool
   run_once: true
   tags:
     - bar_create_recover_image

tripleo_ansible/roles/backup_and_restore/tasks/main.yml

@@ -42,7 +42,7 @@
   import_tasks: service_manager_pause.yml
   when:
     - tripleo_backup_and_restore_service_manager|bool
-    - not tripleo_backup_and_restore_enable_snapshots
+    - not tripleo_backup_and_restore_enable_snapshots|bool
 
 - name: Backup the database
   import_tasks: db_backup.yml
@@ -50,11 +50,19 @@
 - name: Backup pacemaker configuration
   import_tasks: pacemaker_backup.yml
 
-- name: Create recovery images with ReaR
-  import_tasks: run_backup.yml
+- name: Perform backup
+  block:
+    - name: Create recovery images with ReaR
+      import_tasks: run_backup.yml
+  always:
+    - name: Service management
+      import_tasks: service_manager_unpause.yml
+      when:
+        - tripleo_backup_and_restore_service_manager|bool
+        - not tripleo_backup_and_restore_enable_snapshots|bool
 
-- name: Service management
-  import_tasks: service_manager_unpause.yml
-  when:
-    - tripleo_backup_and_restore_service_manager|bool
-    - not tripleo_backup_and_restore_enable_snapshots
+    - name: Pacemaker management
+      import_tasks: pacemaker_unstandby.yml
+      when:
+        - pacemaker_enabled
+        - tripleo_backup_and_restore_enable_snapshots|bool

tripleo_ansible/roles/backup_and_restore/tasks/pacemaker_unstandby.yml

@@ -0,0 +1,30 @@
+---
+# Copyright 2019 Red Hat, Inc.
+# All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# Start again pacemaker
+- name: Add the node to the pacemaker cluster
+  command: pcs node unstandby
+  tags:
+    - bar_create_recover_image
+
+- name: Wait until pacemaker has Galera up&running
+  shell: ss -tunlp | grep ":3306 " | sed -e 's/.*\///'
+  register: mysql_result
+  retries: 300
+  until: mysql_result is search('mysqld')
+  delay: 5
+  tags:
+    - bar_create_recover_image

tripleo_ansible/roles/backup_and_restore/tasks/run_backup.yml

@@ -54,26 +54,6 @@
   tags:
     - bar_create_recover_image
 
-- name: Add the node to the pacemaker cluster
-  command: pcs node unstandby
-  when:
-    - pacemaker_enabled
-    - tripleo_backup_and_restore_enable_snapshots|bool
-  tags:
-    - bar_create_recover_image
-
-- name: Wait until pacemaker has Galera up&running
-  shell: netstat -tunlp | grep ":3306 " | sed -e 's/.*\///'
-  register: mysql_result
-  retries: 10
-  until: mysql_result is search('mysqld')
-  delay: 5
-  when:
-    - pacemaker_enabled
-    - tripleo_backup_and_restore_enable_snapshots|bool
-  tags:
-    - bar_create_recover_image
-
 - name: Clean old backups
   shell: |
     set -o pipefail

tripleo_ansible/roles/backup_and_restore/tasks/service_manager_pause.yml

@@ -39,6 +39,7 @@
     /usr/bin/{{ tripleo_container_cli }} ps --format '{{ '{{' }}.Names {{ '}}' }} ' | /usr/bin/egrep -v 'galera|mysql|bundle'
   register: container_services
   changed_when: container_services.stdout is undefined
+  failed_when: false
   tags:
     - bar_create_recover_image