Add nova to placement DB migration

While transitioning nova-placement to placement we need
to migrate data [1]. This patch adds this required step for properly
migrating placement with all data.

[1] https://docs.openstack.org/placement/latest/admin/upgrade-to-stein.html#migrate-the-data

Change-Id: I4e03ee7c0ead78a1296a8bd8447bce771967d742

tasks/placement_db_sync.yml

@@ -13,6 +13,23 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+- block:
+  - name: Get mysql-migrate-db.sh path
+    command: "{{ placement_bin }}/python -c \"import pkg_resources;print(pkg_resources.resource_filename('placement_db_tools', 'mysql-migrate-db.sh'))\" "
+    become: yes
+    become_user: "{{ placement_system_user_name }}"
+    changed_when: false
+    register: placement_db_tools
+  # NOTE(noonededpunk) We have rc 3 when data is already migrated and rc 4 when no data for migration
+  - name: Perform DB migration from nova-placement
+    command: "{{ placement_db_tools.stdout }} --migrate /etc/placement/placement-migrate-db.rc"
+    become: yes
+    become_user: "{{ placement_system_user_name }}"
+    register: placement_migrate
+    changed_when: placement_migrate.rc == 0
+    failed_when: placement_migrate.rc == 1 or placement_migrate.rc == 2 or placement_migrate.rc >= 5
+  when: placement_migrate_flag | default(False)
+
 - name: Perform a Placement DB sync
   command: "{{ placement_bin }}/placement-manage db sync"
   become: yes

tasks/placement_post_install.yml

@@ -27,3 +27,12 @@
       dest: "/etc/placement/placement.conf"
       config_overrides: "{{ placement_placement_conf_overrides }}"
       config_type: "ini"
+
+- name: Copy placement database migration config
+  template:
+    src: placement-migrate-db.rc.j2
+    dest: /etc/placement/placement-migrate-db.rc
+    owner: "root"
+    group: "{{ item.group|default(placement_system_group_name) }}"
+    mode: "0640"
+  when: placement_migrate_flag | default(False)

templates/placement-migrate-db.rc.j2

@@ -0,0 +1,9 @@
+NOVA_API_DB="{{ nova_api_galera_database | default('nova_api') }}"
+NOVA_API_USER="{{ nova_api_galera_user | default('nova_api') }}"
+NOVA_API_PASS="{{ nova_api_container_mysql_password }}"
+NOVA_API_DB_HOST="{{ nova_api_galera_address | default(placement_galera_address) }}"
+PLACEMENT_DB="{{ placement_galera_database }}"
+PLACEMENT_USER="{{ placement_galera_user }}"
+PLACEMENT_PASS="{{ placement_galera_password }}"
+PLACEMENT_DB_HOST="{{ placement_galera_address }}"
+MIGRATE_TABLES="allocations placement_aggregates consumers inventories projects resource_classes resource_provider_aggregates resource_provider_traits resource_providers traits users"