Skip to content
homelab-docs

Watchtower

Watchtower is a tool for automatically updating running Docker containers. It monitors your containers and checks for updates to their images, allowing you to keep your services up-to-date without manual intervention.

compose.yaml
services:
  watchtower:
    image: containrrr/watchtower:latest
    container_name: watchtower
    ports:
      - 8081:8080
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    environment:
      # WATCHTOWER_DISABLE_CONTAINERS: "" # will ignore labels set. It is worth checking out labels as that can be a more scalabe solution (automatic)
      WATCHTOWER_SCHEDULE: "0 0 4 * * *" # check and update containers daily at 4:00 AM
      WATCHTOWER_CLEANUP: true # remove the old image after restarting a container with a new image
      WATCHTOWER_TIMEOUT: 30s # timeout before the container is forcefully stopped. When set, this option will change the default (10s) wait time to the given value
      WATCHTOWER_REMOVE_VOLUMES: true # remove all anonymous volumes from the container before restarting with a new image. Named volumes will not be removed!
      WATCHTOWER_HTTP_API_TOKEN: ${WATCHTOWER_HTTP_API_TOKEN} # sets an authentication token to HTTP API requests
      WATCHTOWER_HTTP_API_METRICS: true # enables a metrics endpoint, exposing prometheus metrics via HTTP. See Metrics for details.
      WATCHTOWER_NOTIFICATIONS: gotify
      WATCHTOWER_NOTIFICATION_GOTIFY_URL: ${WATCHTOWER_GOTIFY_URL}
      WATCHTOWER_NOTIFICATION_GOTIFY_TOKEN: ${WATCHTOWER_GOTIFY_TOKEN}
      WATCHTOWER_NOTIFICATIONS_HOSTNAME: "watchtower"
      TZ: ${TZ}
    restart: unless-stopped

Configuration

Section titled “Configuration”

You can configure Watchtower by setting environment variables in the compose.yaml file. The example above includes several common configurations, such as scheduling updates, cleaning up old images, and enabling notifications via Gotify.

References