Update "openstack_release" variable to static brach name

Since we use the release name as the default tag to publish images
to Dockerhub, we should use this by default.

This change also removes support for the magic value "auto".

Change-Id: I5610cc7729e9311709147ba5532199a033dfd156
Closes-Bug: #1843518

ansible/bifrost.yml

@@ -1,8 +1,4 @@
 ---
-- import_playbook: detect-release.yml
-  vars:
-    detect_release_hosts: bifrost
-
 - name: Apply role bifrost
   hosts: bifrost
   roles:

ansible/detect-release.yml

@@ -1,16 +0,0 @@
----
-- 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/group_vars/all.yml

@@ -474,7 +474,7 @@ admin_protocol: "http"
 ####################
 # OpenStack options
 ####################
-openstack_release: "auto"
+openstack_release: "master"
 openstack_logging_debug: "False"
 
 openstack_region_name: "RegionOne"

ansible/mariadb_backup.yml

@@ -1,8 +1,4 @@
 ---
-- import_playbook: detect-release.yml
-  vars:
-    detect_release_hosts: mariadb
-
 - name: Backup MariaDB
   hosts: mariadb
   roles:

ansible/mariadb_recovery.yml

@@ -1,8 +1,4 @@
 ---
-- import_playbook: detect-release.yml
-  vars:
-    detect_release_hosts: mariadb
-
 - name: Recover mariadb
   hosts: mariadb
   roles:

ansible/site.yml

@@ -91,10 +91,6 @@
         - enable_zun_{{ enable_zun | bool }}
   tags: always
 
-- import_playbook: detect-release.yml
-  vars:
-    detect_release_hosts: openstack_release_auto
-
 - name: Apply role prechecks
   gather_facts: false
   # Apply only when kolla action is 'precheck'.

releasenotes/notes/deprecated-auto-detect-openstack_release-d96b5ae2fc27f5ac.yaml

@@ -0,0 +1,7 @@
+---
+upgrade:
+  - |
+    Modifies the default value for ``openstack_release`` from ``auto``
+    to the name of the release (e.g. ``train``), or ``master`` on the
+    master branch. The value of ``auto`` will no longer detect the
+    version of the ``kolla-ansible`` Python package.