Lock postgres to version 11

tasks/keycloak.yml

@@ -8,7 +8,7 @@
     force_source: yes
   with_items:
     - jboss/keycloak
-    - postgres
+    - postgres:11
   notify:
     - Re-create the keycloak containers
 

templates/docker-compose.yml

@@ -6,7 +6,7 @@ volumes:
 
 services:
   postgres:
-    image: postgres
+    image: 'postgres:11'
     volumes:
       - postgres_data:/var/lib/postgresql/data
       - /var/backups/keycloak/{{ item.id }}:/tmp/backups