Support new style mirror_info in use-docker-mirror

This adds new style mirror_info handling to use-docker-mirror to give us
greater control over whether or not docker hub should be mirrored. We
ignore old style configuration if new style is present which gives us
this control. Otherwise we fallback to the old behavior.

We also update the ensure-docker test jobs to be triggered by updates to
the use-docker-mirror roles as ensure-docker includes this role. We
should get decent functional testing coverage this way.

Change-Id: Ia1b216a6dd68bcafbe599777037c5d7b1b3e8201

roles/use-docker-mirror/tasks/main.yaml

@@ -1,10 +1,32 @@
-- name: Set mirror_fqdn fact
+- name: Set docker_mirror fact from mirror_info
   when:
-    - mirror_fqdn is not defined
-    - zuul_site_mirror_fqdn is defined
+    - docker_mirror is not defined
+    - mirror_info is defined
+    - dockerhub is in mirror_info
   set_fact:
-    mirror_fqdn: "{{ zuul_site_mirror_fqdn }}"
+    docker_mirror: mirror_info.dockerhub.url
 
+- name: Set docker_mirror fact from zuul_site_mirror_info
+  when:
+    - docker_mirror is not defined
+    - zuul_site_mirror_info is defined
+    - dockerhub is in zuul_site_mirror_info
+  set_fact:
+    docker_mirror: zuul_site_mirror_info.dockerhub.url
+
+# Backward compat fallback to old style mirror_fqdn based url derivation.
+- name: Set docker_mirror fact
+  when:
+    - docker_mirror is not defined
+    - mirror_info is not defined
+    - zuul_site_mirror_info is not defined
+    - mirror_fqdn is defined or zuul_site_mirror_fqdn is defined
+  set_fact:
+    docker_mirror: "http://{{ mirror_fqdn | default(zuul_site_mirror_fqdn) }}:8082"
+
+# Only run when new style mirror_info is defined or old style mirror
+# info is defined and not new style. This forces people using new
+# style to configure dockerhub mirroring there.
 - name: Set up docker mirrors
   include_tasks: mirror.yaml
-  when: mirror_fqdn is defined or docker_mirror is defined
+  when: docker_mirror is defined

roles/use-docker-mirror/tasks/mirror.yaml

@@ -5,17 +5,8 @@
     path: /etc/docker
     mode: 0755
 
-- name: Set docker_mirror fact
-  when:
-    - docker_mirror is not defined
-    - mirror_fqdn is defined
-  set_fact:
-    docker_mirror: "http://{{ mirror_fqdn }}:8082"
-
 - name: Install dockerhub proxy configuration
   become: yes
-  when:
-    - docker_mirror is defined
   template:
     dest: /etc/docker/daemon.json
     group: root

zuul-tests.d/container-roles-jobs.yaml

@@ -4,6 +4,7 @@
     abstract: true
     files:
       - .*ensure-docker.*
+      - roles/use-docker-mirror/.*
       - roles/ensure-package-repositories/.*
       - test-requirements.txt
     run: test-playbooks/ensure-docker.yaml