docker: add support for additional sockets

Add support to configure additional sockets with a new parameter (must
be an array):
container_registry_additional_sockets

Example of value:
container_registry_additional_sockets:
  - /var/lib/openstack/docker.sock
  - /var/run/some-other/docker.sock

Change-Id: I0da7f5f1005532b8ba68c46ed6ca065cc333d0d5

defaults/main.yml

@@ -13,3 +13,4 @@ container_registry_port: 8787
 container_registry_mirror: ''
 container_registry_storage_options: '-s overlay2'
 container_registry_selinux: false
+container_registry_additional_sockets: []

tasks/docker.yml

@@ -49,6 +49,14 @@
   vars:
     registry_flags: "{% for reg in container_registry_insecure_registries %}--insecure-registry {{ reg }}{% if not loop.last %} {% endif %}{% endfor %}"
 
+- name: Create additional socket directories
+  file:
+    path: "{{ item | dirname }}"
+    state: directory
+  notify: restart docker service
+  with_items: "{{ container_registry_additional_sockets }}"
+  when: container_registry_additional_sockets | length > 0
+
 - name: manage /etc/docker/daemon.json
   template:
     src: docker-daemon.json.j2

vars/main.yml

@@ -1 +1 @@
-_full_docker_options: "{% if container_registry_selinux|bool %}--selinux-enabled {% endif %}{{ container_registry_docker_options }}"
+_full_docker_options: "{% if container_registry_selinux|bool %}--selinux-enabled {% endif %}{% if container_registry_additional_sockets | length > 0 %}-H unix:///run/docker.sock {% for soc in container_registry_additional_sockets %}-H unix://{{ soc }}{% if not loop.last %} {% endif %}{% endfor %}{% endif %} {{ container_registry_docker_options }}"