Add handler when systemd is used

The service handler will restart a sysV or upstart init script when
present instead of a systemd service unit. In Xenial both upstart and
systemd service files can be present at the same time which can create
an unintended consequence by restarting the wrong service. This change
creates a guard so that if systemd is used we restart using a systemctl
command otherwise we use the service module.

> NOTE a systemctl command is used because the systemd module is not
  available until ansible 2.2

Change-Id: I71cd03ac0f10e88e83c085b7a87b7b2f710d0c3e
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>

handlers/main.yml

@@ -18,8 +18,15 @@
   when:
     - ansible_service_mgr == 'systemd'
 
-- name: Restart memcached
+- name: Restart memcached (upstart)
   service:
     name: "memcached"
     state: "restarted"
     pattern: "memcached"
+  when:
+    - ansible_service_mgr != 'systemd'
+
+- name: Restart memcached (systemd)
+  command: "systemctl restart memcached"
+  when:
+    - ansible_service_mgr == 'systemd'

tasks/memcached_config.yml

@@ -38,7 +38,9 @@
     owner: "root"
     group: "root"
     mode: "0644"
-  notify: Restart memcached
+  notify:
+    - Restart memcached (upstart)
+    - Restart memcached (systemd)
 
 - name: Create memcached systemd service config dir
   file:
@@ -61,7 +63,8 @@
     - ansible_pkg_mgr == 'apt'
     - ansible_service_mgr != 'systemd'
     - memcached_connections > 1024
-  notify: Restart memcached
+  notify:
+    - Restart memcached (upstart)
 
 - name: Add automatic restart on failure
   template:
@@ -69,7 +72,8 @@
     dest: "/etc/systemd/system/memcached.service.d/systemd-restart-on-failure.conf"
   when:
     - ansible_service_mgr == 'systemd'
-  notify: Restart memcached
+  notify:
+    - Restart memcached (systemd)
 
 - name: Apply resource limits (systemd)
   template:
@@ -83,7 +87,7 @@
     - memcached_connections > 1024
   notify:
     - Reload the systemd daemon
-    - Restart memcached
+    - Restart memcached (systemd)
 
 - name: Configure soft file limits
   lineinfile: