Make nova use a data container

Make nova-libvirt and nova-compute use a data container called
nova_data.  This data container contains /var/lib/nova/instances
data so upgrades to nova-compute work properly.

Change-Id: I89362eb0857f7b07503c35178475bc91d0d19ca8
Closes-Bug: #1486333

ansible/roles/nova/defaults/main.yml

@@ -40,6 +40,10 @@ nova_api_image: "{{ docker_registry ~ '/' if docker_registry else '' }}{{ docker
 nova_api_tag: "{{ openstack_release }}"
 nova_api_image_full: "{{ nova_api_image }}:{{ nova_api_tag }}"
 
+nova_data_image: "{{ docker_registry ~ '/' if docker_registry else '' }}{{ docker_namespace }}/{{ kolla_base_distro }}-{{ kolla_install_type }}-data"
+nova_data_tag: "{{ openstack_release }}"
+nova_data_image_full: "{{ nova_data_image }}:{{ nova_data_tag }}"
+
 
 ####################
 # Openstack

ansible/roles/nova/tasks/bootstrap.yml

@@ -27,6 +27,22 @@
   failed_when: database_user_create.stdout.split()[2] != 'SUCCESS'
   run_once: True
 
+- name: Starting Nova data container
+  docker:
+    docker_api_version: "{{ docker_api_version }}"
+    net: host
+    pull: "{{ docker_pull_policy }}"
+    restart_policy: "{{ docker_restart_policy }}"
+    restart_policy_retry: "{{ docker_restart_policy_retry }}"
+    state: reloaded
+    registry: "{{ docker_registry }}"
+    username: "{{ docker_registry_username }}"
+    password: "{{ docker_registry_password }}"
+    insecure_registry: "{{ docker_insecure_registry }}"
+    name: nova_data
+    image: "{{ nova_data_image_full }}"
+    volumes: "/var/lib/nova/instances"
+
 - name: Starting Nova bootstrap container
   docker:
     detach: False

ansible/roles/nova/tasks/start.yml

@@ -19,7 +19,8 @@
       - "{{ node_config_directory }}/nova-libvirt/:/opt/kolla/nova-libvirt/:ro"
       - "/run:/run"
       - "/sys/fs/cgroup:/sys/fs/cgroup"
-      - "/var/lib/nova/instances"
+    volumes_from:
+      - nova_data
     env:
       KOLLA_CONFIG_STRATEGY: "{{ config_strategy }}"
   when: inventory_hostname in groups['compute']
@@ -142,7 +143,7 @@
       - "/lib/modules:/lib/modules:ro"
       - "/run:/run"
     volumes_from:
-      - nova_libvirt
+      - nova_data
     env:
       KOLLA_CONFIG_STRATEGY: "{{ config_strategy }}"
   when: inventory_hostname in groups['compute']