Allow a deployer to disable container restarts

This changes allows a deployer to disable a container restart
by setting the option ``lxc_container_allow_restarts`` to ``false``.

Forward port based on:
 - https://review.openstack.org/344834
 - https://review.openstack.org/346064

Change-Id: I2c681d7e0681f8586286dc9f371d7b5e231bda68
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>

defaults/main.yml

@@ -18,16 +18,15 @@ debug: False
 
 lxc_container_config: /etc/lxc/lxc-openstack.conf
 lxc_container_default_config_list:
+  - "lxc.start.auto=1"
+  - "lxc.start.delay=15"
+  - "lxc.group=onboot"
+  - "lxc.group=openstack"
   - "lxc.autodev=1"
   - "lxc.pts=1024"
   - "lxc.kmsg=0"
   - "lxc.hook.autodev=/var/lib/lxc/{{ inventory_hostname }}/autodev"
   - "lxc.mount.entry=/openstack/backup/{{ inventory_hostname }} var/backup none defaults,bind,rw 0 0"
-lxc_container_overlayfs_config_list:
-  - "lxc.start.auto=1"
-  - "lxc.start.delay=15"
-  - "lxc.group=onboot"
-  - "lxc.group=openstack"
 lxc_container_config_list: []
 
 # Mappings from Ansible reported architecture to distro release architecture
@@ -83,3 +82,6 @@ lxc_container_download_template_options: >
   --force-cache
   --server {{ lxc_image_cache_server }}
   --variant={{ lxc_container_variant }}
+
+# Toggle the restart of containers via the handler.
+lxc_container_allow_restarts: yes

handlers/main.yml

@@ -20,6 +20,7 @@
   notify:
     - Start Container
   delegate_to: "{{ physical_host }}"
+  when: lxc_container_allow_restarts | bool
 
 - name: Start Container
   lxc_container:

releasenotes/notes/add-lxc-container-restart-option-8c7f5b20b9414ead.yaml

@@ -0,0 +1,8 @@
+---
+features:
+  - A new variable has been added to allow a deployer to control
+    the restart of containers via the handler. This new option is
+    ``lxc_container_allow_restarts`` and has a default of ``yes``.
+    If a deployer wishes to disable the auto-restart functionality
+    they can set this value to ``no`` and automatic container
+    restarts that are not absolutely required will be disabled.

tasks/container_create.yml

@@ -68,8 +68,6 @@
     fs_type: "{{ lxc_container_fs_type }}"
     vg_name: "{{ lxc_container_vg_name }}"
     template_options: "{{ lxc_container_download_template_options }}"
-    container_command: "{{ lxc_container_map.prep_commands }}"
-    container_config: "{{ lxc_container_default_config_list | union(lxc_container_config_list) }}"
   delegate_to: "{{ physical_host }}"
   when:
     - lxc_container_backing_store != "overlayfs"
@@ -105,20 +103,25 @@
   tags:
     - lxc-container-create
 
-# Note that the first four container_config flags are normally applied through
-# the lxc_container module's 'config' option, but the module doesn't support
-# applying that option after the container has been created. This is a workaround
-# until either that is fixed, or a better alternative is identified.
-# TODO(odyssey4me): revisit this for better options some time
-- name: Execute container commands and add container config (overlayfs)
+- name: Write default container config
+  lineinfile:
+    dest: "/var/lib/lxc/{{ inventory_hostname }}/config"
+    line: "{{ item | replace('=', ' = ') | regex_replace('\\s+', ' ') }}"
+    backup: "true"
+  with_items: "{{ lxc_container_default_config_list | union(lxc_container_config_list) }}"
+  delegate_to: "{{ physical_host }}"
+  notify:
+    - Lxc container restart
+  tags:
+    - lxc-container-config
+
+- name: Execute container commands
   lxc_container:
     name: "{{ inventory_hostname }}"
     container_command: "{{ lxc_container_map.prep_commands }}"
-    container_config: "{{ lxc_container_default_config_list | union(lxc_container_overlayfs_config_list) | union(lxc_container_config_list) }}"
   delegate_to: "{{ physical_host }}"
-  when: lxc_container_backing_store == "overlayfs"
   tags:
-    - lxc-container-config
+    - lxc-container-commands
 
 - name: Container network interfaces
   lxc_container: