Ensure fencing is correctly handled during update

If overcloud is deployed with fencing enabled, then
we should temporarily disable fencing for the duration of the update.
We are introducing a pre-undercloud update step to disable
it and post-update step to enable it back.

Change-Id: Ie6324fc2c9cdbeac6126e5bdbbce41f23e143be5
(cherry picked from commit 224d964ba7)

tasks/update/disable_fencing.yaml

@@ -0,0 +1,23 @@
+---
+- name: verify if fencing is enabled before running overcloud update
+  become: true
+  become_user: "{{ (overcloud_ssh_user) | ternary(overcloud_ssh_user, 'heat-admin') }}"
+  delegate_to: "{{ controller_host }}"
+  shell: "sudo pcs property config stonith-enabled | tail -1"
+  register: pcs_out
+  changed_when: false
+  failed_when: false
+
+- block:
+    - name: set EnableFencing to false in fencing.yaml
+      replace:
+        path: "{{ working_dir }}/fencing.yaml"
+        regexp: "EnableFencing: true"
+        replace: "EnableFencing: false"
+
+    - name: disable fencing before running update
+      become: true
+      become_user: "{{ (overcloud_ssh_user) | ternary(overcloud_ssh_user, 'heat-admin') }}"
+      delegate_to: "{{ controller_host }}"
+      shell: "sudo pcs property set stonith-enabled=false"
+  when: pcs_out.stdout.find('true') != -1

tasks/update/enable_fencing.yaml

@@ -0,0 +1,28 @@
+---
+- name: Check if fencing.yaml file is present
+  stat:
+    path: "{{ working_dir }}/fencing.yaml"
+  register: fencing_file
+
+- name: verify the fencing status after update
+  become: true
+  become_user: "{{ (overcloud_ssh_user) | ternary(overcloud_ssh_user, 'heat-admin') }}"
+  delegate_to: "{{ controller_host }}"
+  shell: "sudo pcs property config stonith-enabled | tail -1"
+  register: pcs_out
+  changed_when: false
+  failed_when: false
+
+- block:
+    - name: set EnableFencing to true in fencing.yaml
+      replace:
+        path: "{{ working_dir }}/fencing.yaml"
+        regexp: "EnableFencing: false"
+        replace: "EnableFencing: true"
+
+    - name: enable fencing after running update
+      become: true
+      become_user: "{{ (overcloud_ssh_user) | ternary(overcloud_ssh_user, 'heat-admin') }}"
+      delegate_to: "{{ controller_host }}"
+      shell: "sudo pcs property set stonith-enabled=true"
+  when: pcs_out.stdout.find('false') != -1 and fencing_file.stat.exists

tasks/update/main.yml

@@ -98,6 +98,12 @@
         - updates_validations
         - pre_update_prepare_validations
 
+    - set_fact:
+        controller_host: "{{ inventory_hostmap[controller_role_name]|first }}"
+
+    - name: run pre-update fencing check
+      import_tasks: disable_fencing.yaml
+
     - name: import oc update prepare tasks
       import_tasks: overcloud_update_prepare.yml
       tags:
@@ -201,6 +207,9 @@
         ./overcloud_online_data_migration.sh 2>&1 {{ timestamper_cmd }} >> \
             overcloud_update_data_migration.log
 
+    - name: run post-update fencing check
+      import_tasks: enable_fencing.yaml
+
     - name: run post-update validation
       import_tasks: ../common/validation_group_run.yaml
       vars: