Watchtower

Description

Watchtower is a process for automating Docker container base image updates. It monitors running containers and automatically updates them whenever a new image is available, helping to keep your Docker environment up-to-date and secure.

Overview

Docker compose 

---
services:
  # https://containrrr.dev/watchtower/
  watchtower:
    env_file: .env
    image: containrrr/watchtower
    restart: unless-stopped
    container_name: watchtower
    # ports:
    #   - "3443:3443"
    #   - "3080:3080"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - /etc/localtime:/etc/localtime:ro

Environment variables 

# SMTP
WATCHTOWER_NOTIFICATIONS=email # Enable email notifications
WATCHTOWER_NOTIFICATION_EMAIL_FROM=<your email> # Your email address
WATCHTOWER_NOTIFICATION_EMAIL_TO=<your email> # Can be a comma-separated list
WATCHTOWER_NOTIFICATION_EMAIL_SERVER=smtp.gmail.com # Your SMTP server
WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PORT=587 # 465 for SSL, 587 for TLS
WATCHTOWER_NOTIFICATION_EMAIL_SERVER_USER=<your email> # Your email address
WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PASSWORD=<your password> # Consider using an app password
WATCHTOWER_NOTIFICATION_EMAIL_DELAY=2 # minutes
WATCHTOWER_NOTIFICATIONS_LEVEL=info # info, warning, error

# Rolling restart
WATCHTOWER_ROLLING_RESTART=true # Enable rolling restarts

# Schedule
WATCHTOWER_SCHEDULE=0 0 5 * * * # Daily at 5am

# Notification
WATCHTOWER_NOTIFICATIONS_HOSTNAME=draxpi # Hostname to use in notifications

Issues 

Error response from daemon: client version 1.25 is too old. Minimum supported API version is 1.44, please upgrade your client to a newer version

Minimum supported API version is 1.44 so we gonna set the DOCKER_API_VERSION to 1.41 which is the latest version supported by watchtower as of this writing. This will allow watchtower to communicate with the Docker daemon without encountering the version mismatch error.

To fix it, add the following environment variable to the watchtower service:

DOCKER_API_VERSION=1.41
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