Optimise the role execution

This patch does the following:

- Instead of scoping to the inventory group name, we scope
  to the play hosts. This allows the execution of the role
  using limits to still execute the necessary tasks.

- A little style update is done to improve readability.

- Some includes are changed from static to dynamic to
  improve execution speed.

- The tag for the translations async finalisation is
  changed to 'horizon-config' to match the rest of the
  config related tasks, including the task which starts the
  async process.

- The enabling and starting up of Apache is moved to the
  handler so that it's all done in one task.

Conflicts:
>------tasks/main.yml

Change-Id: If9726035d1fae0ec78aead38eb85f4d30a45a07c
(cherry picked from commit faa5b91e1f)

handlers/main.yml

@@ -16,4 +16,6 @@
 - name: Restart apache2
   service:
     name: "{{ horizon_system_service_name }}"
+    enabled: yes
     state: "restarted"
+    daemon_reload: "{{ (ansible_service_mgr == 'systemd') | ternary('yes', omit) }}"

tasks/horizon_apache.yml

@@ -41,8 +41,8 @@
   template:
     src: "{{ item.src }}"
     dest: "{{ item.dest }}"
-    owner: "{{ item.owner|default(horizon_system_user_name) }}"
-    group: "{{ item.group|default(horizon_system_group_name) }}"
+    owner: "{{ item.owner | default(horizon_system_user_name) }}"
+    group: "{{ item.group | default(horizon_system_group_name) }}"
   with_items: "{{ horizon_apache_configs }}"
   notify: Restart apache2
 
@@ -83,17 +83,11 @@
     line: "ServerSignature {{ horizon_apache_serversignature }}"
   notify: Restart apache2
 
-# Removing the Listen from apache config to prevent conflick with ports.conf on CentOS
-- name: remove Listen from Apache config
+# Removing the Listen from apache config to prevent conflicts with ports.conf on CentOS
+- name: Remove Listen from Apache config
   lineinfile:
     dest: "{{ horizon_apache_security_conf }}"
     regexp: '^(Listen.*)'
     backrefs: yes
     line: '#\1'
   notify: Restart apache2
-
-- name: Load service
-  service:
-    name: "{{ horizon_system_service_name }}"
-    enabled: "yes"
-    state: "started"

tasks/main.yml

@@ -37,28 +37,29 @@
     - horizon-config
 
 - include: horizon_db_setup.yml
-  when: inventory_hostname == groups['horizon_all'][0]
+  static: no
+  when: inventory_hostname == ansible_play_hosts[0]
   tags:
     - horizon-config
 
 - include: horizon_ssl_self_signed.yml
   static: no
   when:
-    - not horizon_external_ssl|bool
+    - not horizon_external_ssl | bool
     - horizon_user_ssl_cert is not defined or horizon_user_ssl_key is not defined
   tags:
     - horizon-config
 
 - include: horizon_ssl_user_provided.yml
   static: no
-  when: not horizon_external_ssl|bool
+  when: not horizon_external_ssl | bool
   tags:
     - horizon-config
 
 - name: Update the ca certificates
   command: "update-ca-certificates -f"
   when:
-   - not horizon_external_ssl|bool
+   - not horizon_external_ssl | bool
    - ansible_pkg_mgr == 'apt'
   tags:
     - horizon-config