A solution for watching your Docker® containers running via Docker Compose for image updates and automatically restarting the compositions whenever an image is refreshed.

Overview

Compose Updater is an application which continuously monitors your running docker containers. When a base image is changed, the updated version gets pulled (or built via --pull) from the registry and the docker compose composition gets restarted (via down and up -d).

Usage

1. Prepare your services

You'll need to add two labels to the services you want to watch:

version: '3'
services:
  web:
    image: nginx:alpine
    labels:
      - "docker-compose-watcher.watch=1"
      - "docker-compose-watcher.dir=/home/docker/dir"

docker-compose-watcher.watch=1 exposes the service to Compose Updater.

docker-compose-watcher.dir specifies the path to the directory where this docker-compose.yml lives. If the file is not named docker-compose.yml, you can instead use the label docker-compose-watcher.file to specify the correct path and file name. This is necessary because it's not possible to find the docker-compose.yml from a running container.

2. Run Compose Updater

Run Docker Compose Watcher using compose:

version: '3'
services:
  watcher:
    image: virtualzone/compose-updater
    restart: always
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock:ro"
      - "/home/docker:/home/docker:ro"
    environment:
      INTERVAL: 60

It's important to mount /var/run/docker.sock and the directory your compose files reside in (/home/docker in the example above).

Note: You'll only need one Compose Updater instance for all your compose services (not one per docker-compose.yml).

Settings

Configure Compose Updater via environment variables (recommended) or command line arguments:

Env	Param	Default	Meaning
INTERVAL	-interval	60	Minutes between checks
CLEANUP	-cleanup	1	Run docker system prune -a -f after each run
ONCE	-once	0	Run once and exit
PRINT_SETTINGS	-printSettings	1	Print settings on start
UPDATE_LOG	-updateLog	''	Log file for updates and restarts

License

GNU General Public License v3.0

Docker® is a trademark of Docker, Inc.

This project is not affiliated with Docker, Inc.