Use apt_repository update_cache feature

With ansible 2.2, apt_repository update_cache feature has
been fixed. When a new repo will be added, apt-get update
will be run after the addition if update_cache is set to yes.

This combined with the apt module now properly checking the
cache validity, we can now have proper updating of the cache
with registering variables.

Change-Id: I70a9892f11c754aba44a7a6e0d99cec515ba3e33

tasks/nova_compute_powervm_install.yml

@@ -29,6 +29,7 @@
   apt_repository:
     repo: "{{ novalink_repo.repo }}"
     state: "{{ novalink_repo.state }}"
+    update_cache: yes
   register: add_nv_repos
   until: add_nv_repos|success
   retries: 5
@@ -36,16 +37,6 @@
   tags:
     - novalink-repo
 
-- name: Update apt if needed
-  apt:
-    update_cache: yes
-  when: add_nv_repos|changed
-  tags:
-    - nova-apt-packages
-    - nova-compute-powervm-apt-packages
-    # do not trigger ANSIBLE0016
-    - skip_ansible_lint
-
 - name: Install apt packages
   apt:
     pkg: "{{ item }}"

tasks/nova_install_apt.yml

@@ -17,6 +17,8 @@
   apt:
     pkg: ubuntu-cloud-keyring
     state: "{{ nova_package_state }}"
+    update_cache: yes
+    cache_valid_time: "{{ cache_timeout }}"
   when: nova_uca_enable
   register: nova_uca_add_keys
   tags:
@@ -26,6 +28,7 @@
   apt_repository:
     repo: "{{ uca_repo }}"
     state: present
+    update_cache: yes
   register: nova_uca_add_repo
   when: nova_uca_enable
   until: add_repo|success
@@ -34,13 +37,6 @@
   tags:
     - add-uca-repo
 
-- name: Update apt if needed
-  apt:
-    update_cache: yes
-  when: nova_uca_add_keys | changed or nova_uca_add_repo | changed
-  tags:
-    - nova-apt-packages
-
 - name: Install apt packages (common)
   apt:
     pkg: "{{ item }}"