UCA support for nova compute

This changes adds the Ubuntu Cloud Archive repo support for the nova
compute kvm. UCA repo is important to support architecture ppc64le
since the default Ubuntu trusty repo does not contain the all required
packages for libvirt-bin.

Change-Id: Ic1e7619b48a9b12ba876f83507497cf1e557223a

defaults/main.yml

@@ -403,3 +403,11 @@ nova_nova_conf_overrides: {}
 nova_rootwrap_conf_overrides: {}
 nova_api_paste_ini_overrides: {}
 nova_policy_overrides: {}
+
+# Ubuntu Cloud Archive variables
+nova_uca_enable: True
+uca_openstack_release: mitaka
+uca_apt_repo_url: "http://ubuntu-cloud.archive.canonical.com/ubuntu"
+uca_repo_dist: "{{ ansible_lsb.codename }}-updates/{{ uca_openstack_release }}"
+uca_repo: "deb {{ uca_apt_repo_url }} {{ uca_repo_dist }} main"
+

releasenotes/notes/nova-uca-support-409b2e6afbce47b1.yaml

@@ -0,0 +1,10 @@
+---
+features:
+  - Nova UCA repository support is implemented by default.
+    This will allow the users to benefit from the updated
+    packages for KVM.
+
+    The ``nova_uca_enable`` variable controls the install
+    source for the KVM packages. By default this value is set
+    to ``True`` to make use of UCA repository. User can set to
+    ``False`` to disable.

tasks/nova_compute_kvm_install.yml

@@ -13,6 +13,26 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+- name: Add ubuntu cloud archive key package
+  apt:
+    pkg: ubuntu-cloud-keyring
+  when: nova_uca_enable
+  register: add_keys
+  tags:
+    - add-apt-keys
+
+- name: Add UCA repo(s)
+  apt_repository:
+    repo: "{{ uca_repo }}"
+    state: present
+  register: add_repo
+  when: nova_uca_enable
+  until: add_repo|success
+  retries: 5
+  delay: 2
+  tags:
+    - add-uca-repo
+
 #TODO(evrardjp): Replace the next 2 tasks by a standard apt with cache
 #when https://github.com/ansible/ansible-modules-core/pull/1517 is merged
 #in 1.9.x or we move to 2.0 (if tested working)
@@ -27,7 +47,8 @@
 - name: Update apt if needed
   apt:
     update_cache: yes
-  when: "ansible_date_time.epoch|float - apt_cache_stat.stat.mtime > {{cache_timeout}}"
+  when: ("ansible_date_time.epoch|float - apt_cache_stat.stat.mtime > {{cache_timeout}}" or
+        add_keys|changed or add_repo|changed)
   tags:
     - nova-apt-packages
     - nova-compute-kvm-apt-packages