Allow magnum role to pull images

Change-Id: Ia7a0bb934827f37af6091895b95ece95a9e3c874
Partially-Implements: blueprint pre-pull-images

ansible/roles/magnum/tasks/deploy.yml

+---
+- include: register.yml
+  when: inventory_hostname in groups['magnum-api']
+
+- include: config.yml
+  when: inventory_hostname in groups['magnum-api'] or
+        inventory_hostname in groups['magnum-conductor']
+
+- include: bootstrap.yml
+  when: inventory_hostname in groups['magnum-api']
+
+- include: start.yml
+  when: inventory_hostname in groups['magnum-api'] or
+        inventory_hostname in groups['magnum-conductor']

ansible/roles/magnum/tasks/main.yml

 ---
-- include: register.yml
-  when: inventory_hostname in groups['magnum-api']
-
-- include: config.yml
-  when: inventory_hostname in groups['magnum-api'] or
-        inventory_hostname in groups['magnum-conductor']
-
-- include: bootstrap.yml
-  when: inventory_hostname in groups['magnum-api']
-
-- include: start.yml
-  when: inventory_hostname in groups['magnum-api'] or
-        inventory_hostname in groups['magnum-conductor']
+- include: "{{ action }}.yml"

ansible/roles/magnum/tasks/pull.yml

+---
+- name: Pulling magnum-api image
+  kolla_docker:
+    action: "pull_image"
+    common_options: "{{ docker_common_options }}"
+    image: "{{ magnum_api_image_full }}"
+  when: inventory_hostname in groups['magnum-api']
+
+- name: Pulling magnum-conductor image
+  kolla_docker:
+    action: "pull_image"
+    common_options: "{{ docker_common_options }}"
+    image: "{{ magnum_conductor_image_full }}"
+  when: inventory_hostname in groups['magnum-conductor']