Watchtower - Automatically Update Docker Containers

Overview

Watchtower by containerrr is a Docker application that will automatically scan the docker containers you are running and update them when a new and updated Docker image is pushed to the docker registry

Prerequisites

Seting up Option 1

To set this up you simply need to do the following:

You can either set up a Portainer Stack or you can simply run a terminal docker run command:

$ docker run -d \
--name watchtower \
-v /var/run/docker.sock:/var/run/docker.sock \
containrrr/watchtower

Copy and paste the following Docker Compose YAML into the text window in Portainer:

version: "3"
services:
  watchtower:
    image: containrrr/watchtower
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock

Setting up Option 2

If you have essential services running that you cannot afford to lengthy downtimes on, I would recommend setting up method 2.

Watchtower will automatically send you an email notification when a container update is available.

Simply copy paste the following Docker Compose YAML, ensuring to read the comments:

version: '3.8'
services:
  watchtower:
    image: containrrr/watchtower:latest
    container_name: watchtower
    environment:
      - 'WATCHTOWER_MONITOR_ONLY=true'
      - 'WATCHTOWER_NOTIFICATIONS=email' #tell watchtower to send emails
      - '[email protected]'
      - '[email protected]'
      - '[email protected]'
      - 'WATCHTOWER_NOTIFICATION_EMAIL_SERVER=smtp.domain.com'
      - 'WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PASSWORD=password_for_user'
      - 'WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PORT=587' #configure accordingly
      - 'WATCHTOWER_NOTIFICATION_EMAIL_DELAY=2' 
      - 'WATCHTOWER_SCHEDULE=* * * 4 * *'
      #Note Watchtower uses 6 digit cron expression
      - 'TZ=Europe/London' #Set timezone
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock

And click Deploy Stack. You should receive an email of all the Apps that may have available updates!

Links

You’re done!