Update container definitions to run all services as a non-root user.

vars/containers/watchtower.yml

@@ -7,10 +7,20 @@ watchtower:
   # Define the docker image to be used for this container.
   image: "{{ feedstack_watchtower_container_image }}:{{ feedstack_watchtower_container_tag }}"
 
+  # Define the user that the container should be run as.
+  user: "{{ docker_user_id }}:{{ docker_group_id }}"
+
   # Define the path where application data for this container will be stored.
   appdata_directory: "{{ docker_appdata_directory }}/watchtower"
 
   # Define the volumes that should be mounted into the container.
   volumes:
     - "/var/run/docker.sock:/var/run/docker.sock"
+    - "{{ docker_home_directory }}/.docker:/config:ro"
+
+  # Define environment variables to be passed to the container.
+  environment_variables:
+    - "WATCHTOWER_CLEANUP=true"
+    - "DOCKER_CONFIG=/config"
+
 ...