Simplified watchtower setup

watchtower/docker-compose.yml

@@ -5,6 +5,10 @@ services:
         image: 'containrrr/watchtower'
         restart: 'always'
 
+        environment:
+            - 'WATCHTOWER_LABEL_ENABLE=true'
+        labels:
+            - 'com.centurylinklabs.watchtower.enable=true'
         volumes:
             - '/var/run/docker.sock:/var/run/docker.sock'
             - '/etc/timezone:/etc/timezone:ro'

watchtower/watchtower.env.example

@@ -1 +0,0 @@
-WATCHTOWER_LABEL_ENABLE=true