Add option to recreate containers

The `lxc_container_recreate` variable will allow for recreating already
deployed containers using either a playbook or a command line argument.

This option is most useful during an upgrade, where the containers are
thrown away and completely rebuilt from scratch.

Change-Id: I3ba35daf49111a3fdfb2e30cffddd9af23aafb28

defaults/main.yml

@@ -126,3 +126,6 @@ lxc_container_network_veth_pair: "{{ lxc_container_network_veth_pair_prefix }}_{
 
 # Enable fixed mac address generation for an lxc container
 lxc_container_fixed_mac: false
+
+# Enable destroying then recreating containers
+lxc_container_recreate: false

releasenotes/notes/recreate-option-d78bae1fd922a84d.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - Added the ``lxc_container_recreate`` option, which will destroy then
+    recreate LXC containers. The container names and IP addresses will remain
+    the same, as will the MAC addresses of any containers using the
+    ``lxc_container_fixed_mac`` setting.

tasks/container_destroy.yml

@@ -0,0 +1,26 @@
+---
+# Copyright 2017, Rackspace US, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+- name: Delete container from host
+  lxc_container:
+    name: "{{ inventory_hostname }}"
+    state: "absent"
+  delegate_to: "{{ physical_host }}"
+
+- name: Destroy container service directories
+  file:
+    path: "/var/lib/lxc/{{ container_name }}"
+    state: "absent"
+  delegate_to: "{{ physical_host }}"

tasks/main.yml

@@ -48,6 +48,12 @@
   tags:
     - always
 
+- include: container_destroy.yml
+  when:
+    - lxc_container_recreate | bool
+  tags:
+    - lxc-container-recreate
+
 - include: container_create.yml
   when:
     - physical_host is defined