podman: Support registry mirror

Change-Id: Ifc09da0b48d950fe010229c484f5f0a33b8648b8

roles/podman/defaults/main.yml

@@ -15,5 +15,8 @@ podman_runtime_directory:
 podman_registry:
 podman_registry_insecure: false
 
-# Path to a CA file for Docker registry
+# Podman registry mirror
+podman_registry_mirror:
+
+# Path to a CA file for registry
 podman_registry_ca:

roles/podman/tasks/config.yml

@@ -23,6 +23,19 @@
     mode: 0644
   when: podman_registry is not none
 
+- name: Write registry mirror config
+  become: True
+  vars:
+    registry_mirror: |
+      [[registry.mirror]]
+      prefix = docker.io
+      location = "{{ podman_registry_mirror }}"
+  copy:
+    content: "{{ registry_mirror }}"
+    dest: /etc/containers/registries.conf.d/registry-mirror.conf
+    mode: 0644
+  when: podman_registry_mirror is not none
+
 - name: Write storage config
   become: True
   vars: