playbooks: os-lxc-container-setup: Only stop the container if it's running

Sometimes, despite the container being started by the
lxc_container_create role, we may find it stopped when we try to
restart it as we see in the following error

TASK [Lxc container restart] ***************************************************
Thursday 12 October 2017  16:56:03 +0000 (0:00:03.191)       2:11:34.445 ******
FAILED - RETRYING: Lxc container restart (3 retries left).
FAILED - RETRYING: Lxc container restart (2 retries left).
FAILED - RETRYING: Lxc container restart (1 retries left).
fatal: [controller00_horizon_container-a0c1ea76 -> 172.29.236.11]:
FAILED! => {"attempts": 3, "changed": true, "cmd": ["lxc-stop", "--name", "controller00_horizon_container-a0c1ea76", "--logfile",
"/var/log/lxc/lxc-controller00_horizon_container-a0c1ea76.log", "--logpriority", "INFO", "-t 10"], "delta": "0:00:00.019918", "end":
"2017-10-12 16:56:41.885367", "failed": true, "rc": 2, "start": "2017-10-12 16:56:41.865449", "stderr": "controller00_horizon_container-a0c1ea76 is not running",
"stderr_lines": ["controller00_horizon_container-a0c1ea76 is not running"], "stdout": "", "stdout_lines": []}

It's not exactly clear why the container stopped by itself so lets try
to workaround this by simply checking if the container is actually
running before we try to stop it. If the container is still in an unusable
state, then the lxc-start command that follows this task will fail anyway.

Change-Id: I179f9f5dd08c74eaa88666dc19698fcb348703eb

playbooks/common-tasks/os-lxc-container-setup.yml

@@ -88,6 +88,18 @@
   tags:
     - common-lxc
 
+- name: Check container state
+  command: "lxc-info -n {{ inventory_hostname }} --state"
+  changed_when: false
+  delegate_to: "{{ physical_host }}"
+  register: _lxc_container_state
+  until: _lxc_container_state | success
+  retries: 3
+  delay: 5
+  when:
+    - not is_metal | bool
+    - (_mc is defined and _mc | changed) or (_ec is defined and _ec | changed)
+
 # Due to https://github.com/ansible/ansible-modules-extras/issues/2691
 # this uses the LXC CLI tools to ensure that we get logging.
 # TODO(odyssey4me): revisit this once the bug is fixed and released
@@ -103,6 +115,7 @@
   when:
     - not is_metal | bool
     - (_mc is defined and _mc | changed) or (_ec is defined and _ec | changed)
+    - _lxc_container_state.stdout.find('RUNNING') != -1
   tags:
     - common-lxc