What is Docker Compose ?

Compose is a tool for defining and running complex applications with Docker. With Compose, you define a multi-container application in a single file, then spin your application up in a single command which does everything that needs to be done to get it running.

More information on the official Docker documentation : https://docs.docker.com/compose/

How do you use this image ?

Interactive and basic mode :

Just run it as a normal command, sharing the directory containing your docker-compose.yml file and the Docker Unix socket :

$ docker run -v "$(pwd)":/app \
             -v /var/run/docker.sock:/var/run/docker.sock \
             -e COMPOSE_PROJECT_NAME=$(basename "$(pwd)") \
             -ti --rm \
             rastermedia/docker-compose:latest --help

Customize the Docker socket

When using another socket than the default Unix one (remote Docker engine use case), you can provide the path to docker-compose using the DOCKER_HOST environment variable. In this example, we'll call docker-compose non-interactively (from a bash script for example), given that the Docker daemon listen through a TCP connection at 10.0.2.15:2375 :

$ docker run -v "$(pwd)":/app \
             -e DOCKER_HOST=tcp://10.0.2.15:2375 \
             -e COMPOSE_PROJECT_NAME=$(basename "$(pwd)") \
             --rm \
             rastermedia/docker-compose:latest up -d

On Windows when using the Boot2Docker provided MSYS shell, you should add / before each of the host paths passed to -v, to help the path conversion :

$ docker run -v "/$(pwd)":/app \
             -v //var/run/docker.sock:/var/run/docker.sock \
             -e COMPOSE_PROJECT_NAME=$(basename "/$(pwd)") \
             -ti --rm \
             rastermedia/docker-compose:latest

Note: On Windows, if you are using MSYS v2 or Cygwin (where pwd in the home directory returns /home/Foo, rather than /c/Users/Foo), you'll also need to replace $(pwd) with $(pwd | sed s_/home_/c/Users_), so the correct directory is mounted.

Convenience mode :

If you don't want to repeat yourself by typing all the options each time, just add an alias (interactive or in your .profile/.ashrc/etc :

    echo 'alias docker-compose="docker run -v \"\$(pwd)\":/app -v /var/run/docker.sock:/var/run/docker.sock -e COMPOSE_PROJECT_NAME=\$(basename \"\$(pwd)\") -ti --rm rastermedia/docker-compose:latest"' \
    >> ~/.ashrc

Customize image from your custom Dockerfile

If the image doesn't fit your needs "as it", you can customize it using your own Dockerfile, for example :

FROM rastermedia/docker-compose:latest
MAINTAINER your.mail@here

ADD . /app/ # your docker-compose.yml can be copied inside the image
ENV DOCKER_HOST tcp://192.168.0.1:2375 # Customize the docker socket

# Your custom stuff here if needed

Note that ENTRYPOINT will be inherited.

Run it now (without option while you provide them inside the image instead of at run time ) :

    docker build -t you/docker-compose ./
    docker run -ti --rm you/docker-compose ps

Volumes : relative and absolute

Be careful using volumes : since the goal of this image is to wrap docker-compose inside a container, you have to provide the right volume's path to the right actor.

This issue explains how : https://github.com/dduportal/dockerfiles/issues/5 .

The idea is to provide a full "host point of view path" for the volume to mount, since the containerised docker-compose may not have access to the full filesystem.

Contributing

Contributions should go to: https://github.com/dduportal/dockerfiles

This is a fork because the Alpine distro they use doesn't properly read files.