From c35cacbf4c060d1b43267a2cb6ba4e4fe8443fe7 Mon Sep 17 00:00:00 2001
From: Jesse Pretorius <jesse.pretorius@rackspace.co.uk>
Date: Tue, 2 May 2017 11:27:37 +0100
Subject: [PATCH] Optimise apt cache update task

The update of the apt cache and the package installation
can all be handled in a single task by providing the
package action plugin with the right parameters. This
removes an extra task to optimise execution.

Also, Ansible 2.x allows the package module to consume
the package list in the name parameter instead of using
a with_items loop which further optimises the execution.

The minimum Ansible version is raised to 2.2 due to a
known bug [1] in Ansible's apt module which does not
update the cache properly if the cache update and the
install are combined in a single task.

[1] https://github.com/ansible/ansible-modules-core/issues/1497

Change-Id: Ia15e468a70f1ac90d8b7ce88f930f81e01afa3d4
---
 meta/main.yml             |  2 +-
 tasks/horizon_install.yml | 12 +++---------
 2 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/meta/main.yml b/meta/main.yml
index f3f502be..697d4adf 100644
--- a/meta/main.yml
+++ b/meta/main.yml
@@ -18,7 +18,7 @@ galaxy_info:
   description: Installation and setup of horizon
   company: Rackspace
   license: Apache2
-  min_ansible_version: 2.0
+  min_ansible_version: 2.2
   platforms:
     - name: Ubuntu
       versions:
diff --git a/tasks/horizon_install.yml b/tasks/horizon_install.yml
index 73412dc7..fcd1e43d 100644
--- a/tasks/horizon_install.yml
+++ b/tasks/horizon_install.yml
@@ -13,13 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-- name: Ensure apt cache is up to date
-  apt:
-    update_cache: yes
-    cache_valid_time: "{{ cache_timeout }}"
-  when:
-    - ansible_pkg_mgr == 'apt'
-
 - name: Create horizon dir
   file:
     path: "{{ item.path }}"
@@ -46,13 +39,14 @@
 
 - name: Install distro packages
   package:
-    name: "{{ item }}"
+    name: "{{ horizon_distro_packages }}"
     state: "{{ horizon_package_state }}"
+    update_cache: "{{ (ansible_pkg_mgr == 'apt') | ternary('yes', omit) }}"
+    cache_valid_time: "{{ (ansible_pkg_mgr == 'apt') | ternary(cache_timeout, omit) }}"
   register: install_packages
   until: install_packages|success
   retries: 5
   delay: 2
-  with_items: "{{ horizon_distro_packages }}"
 
 - name: Create developer mode constraint file
   copy: