Factor out OpenStack release detection playbook

We copy-paste the same play into various playbooks to detect
openstack_release. This change factors that code into a separate
playbook that is imported.

Change-Id: I5fea005642b960080bf5e43455618dc24766c386

ansible/bifrost.yml

 ---
-- name: Detect openstack_release variable
-  hosts: bifrost
-  gather_facts: false
-  tasks:
-    - name: Get current kolla-ansible version number
-      local_action: command python -c "import pbr.version; print(pbr.version.VersionInfo('kolla-ansible'))"
-      register: kolla_ansible_version
-      changed_when: false
-      when: openstack_release == "auto"
-
-    - name: Set openstack_release variable
-      set_fact:
-        openstack_release: "{{ kolla_ansible_version.stdout }}"
-      when: openstack_release == "auto"
-  tags: always
+- import_playbook: detect-release.yml
+  vars:
+    detect_release_hosts: bifrost
 
 - name: Apply role bifrost
   hosts: bifrost

ansible/detect-release.yml

+---
+- name: Detect openstack_release variable
+  hosts: "{{ detect_release_hosts }}"
+  gather_facts: false
+  tasks:
+    - name: Get current kolla-ansible version number
+      local_action: command python -c "import pbr.version; print(pbr.version.VersionInfo('kolla-ansible'))"
+      register: kolla_ansible_version
+      changed_when: false
+      when: openstack_release == "auto"
+
+    - name: Set openstack_release variable
+      set_fact:
+        openstack_release: "{{ kolla_ansible_version.stdout }}"
+      when: openstack_release == "auto"
+  tags: always

ansible/mariadb_backup.yml

 ---
-- name: Detect openstack_release variable
-  hosts: mariadb
-  gather_facts: false
-  tasks:
-    - name: Get current kolla-ansible version number
-      local_action: command python -c "import pbr.version; print(pbr.version.VersionInfo('kolla-ansible'))"
-      register: kolla_ansible_version
-      changed_when: false
-      when: openstack_release == "auto"
-
-    - name: Set openstack_release variable
-      set_fact:
-        openstack_release: "{{ kolla_ansible_version.stdout }}"
-      when: openstack_release == "auto"
-  tags: always
+- import_playbook: detect-release.yml
+  vars:
+    detect_release_hosts: mariadb
 
 - name: Backup MariaDB
   hosts: mariadb

ansible/mariadb_recovery.yml

 ---
-- name: Detect openstack_release variable
-  hosts: mariadb
-  gather_facts: false
-  tasks:
-    - name: Get current kolla-ansible version number
-      local_action: command python -c "import pbr.version; print(pbr.version.VersionInfo('kolla-ansible'))"
-      register: kolla_ansible_version
-      changed_when: false
-      when: openstack_release == "auto"
-
-    - name: Set openstack_release variable
-      set_fact:
-        openstack_release: "{{ kolla_ansible_version.stdout }}"
-      when: openstack_release == "auto"
-  tags: always
+- import_playbook: detect-release.yml
+  vars:
+    detect_release_hosts: mariadb
 
 - name: Recover mariadb
   hosts: mariadb

ansible/site.yml

@@ -32,21 +32,9 @@
         - (ansible_play_batch | length) != (groups['all'] | length)
   tags: always
 
-- name: Detect openstack_release variable
-  hosts: all
-  gather_facts: false
-  tasks:
-    - name: Get current kolla-ansible version number
-      local_action: command python -c "import pbr.version; print(pbr.version.VersionInfo('kolla-ansible'))"
-      register: kolla_ansible_version
-      changed_when: false
-      when: openstack_release == "auto"
-
-    - name: Set openstack_release variable
-      set_fact:
-        openstack_release: "{{ kolla_ansible_version.stdout }}"
-      when: openstack_release == "auto"
-  tags: always
+- import_playbook: detect-release.yml
+  vars:
+    detect_release_hosts: all
 
 - name: Apply role prechecks
   gather_facts: false