Fetch images in a standalone role

This functionality is useful in non-libvirt environments, so separate it
and include it with the new Ansible 2.2 include_role method.

Change-Id: I2ed5dd8115cce012a007b7d791777b052034a17a

roles/fetch-images/meta/main.yml

@@ -0,0 +1,2 @@
+dependencies:
+  - common

roles/fetch-images/tasks/fetch.yml

@@ -1,20 +1,3 @@
-# Fetching the undercloud images can take a long time.  This
-# tasklist caches images in `{{ image_cache_dir }}` if an image is
-# (a) downloaded successfully and (b) successfully verifies against
-# the checksum.  Images are cached using the checksum as the filename,
-# and subsequent playbook runs will use the cached copy rather than
-# trying to fetch the remote copy.
-
-# This checks that the image_cache_dir directory exists.  When running
-# the full quickstart, this is created by the provision/remote role.
-# If you are running this role by itself, you will need to ensure that
-# either the directory exists ahead of time or that ansible has the
-# permissions to create the directory.
-- name: Ensure image cache directory exists
-  file:
-    path: "{{ image_cache_dir }}"
-    state: directory
-
 # Set some convenience variables here to avoid boilerplate code
 # elsewhere in this file.  These are all set unconditionally to avoid
 # any cruft leftover from a previous call to this file.

roles/fetch-images/tasks/main.yml

@@ -0,0 +1,21 @@
+# Fetching the undercloud images can take a long time.  This
+# role caches images in `{{ image_cache_dir }}` if an image is
+# (a) downloaded successfully and (b) successfully verifies against
+# the checksum.  Images are cached using the checksum as the filename,
+# and subsequent playbook runs will use the cached copy rather than
+# trying to fetch the remote copy.
+
+# This checks that the image_cache_dir directory exists.  When running
+# the full quickstart, this is created by the provision/remote role.
+# If you are running this role by itself, you will need to ensure that
+# either the directory exists ahead of time or that ansible has the
+# permissions to create the directory.
+- name: Ensure image cache directory exists
+  file:
+    path: "{{ image_cache_dir }}"
+    state: directory
+
+- include: fetch.yml
+  vars:
+    image: "{{ item }}"
+  with_items: "{{ images }}"

roles/libvirt/setup/undercloud/tasks/main.yml

@@ -31,10 +31,9 @@
   # Conditionally include a playbook for all the images specified
   # in options that downloads, cache and extract if tar archived
   # only if the images aren't already in volume pool
-  - include: fetch_image.yml
-    vars:
-      image: "{{ item }}"
-    with_items: "{{ images }}"
+  - name: Fetch the images
+    include_role:
+      name: fetch-images
 
   # Conditionally include a playbook for all the images specified
   # in options that updates images to the latest delorean version