start2/docker-compose-ansible repository overview

⁠Description

The main purpose of this image is to help in Continuous Integration environments that need the docker binary, the docker-compose binary, and possibly require doing other small things, like running shell scripts or notifying some API with curl.

It includes (docker,docker-compose and ansible) and allows to run arbitrary shell scripts (contrary to the official Docker Compose image).

By not having to install docker-compose on top of a docker:latest image it can reduce the building time about 10 / 15 seconds in a cloud data center for each build. In environments in where the Internet connection is less good than a cloud provider, the time saved would be more.

GitHub repo: https://github.com/2start/docker-compose-ansible⁠

Largly copied from: https://github.com/tiangolo/docker-with-compose⁠

Docker Hub image: https://hub.docker.com/r/start2/docker-compose-ansible/⁠

⁠Usage

Pull the image:

docker pull start2/docker-compose-ansible

Then run a container of this image mounting the Docker sock as a host volume.

By mounting the Docker sock as a volume you allow the docker client inside of the container to communicate with your Docker (the Docker daemon/service) on your machine directly.

This way, you can send Docker commands, like pulling, running, or building a new Docker image, from inside this container.

You might also want to mount a host volume with the files that you need to use.

For example, let's say you have a Dockerfile like:

FROM nginx

RUN echo "Hello World" > /usr/share/nginx/html/index.html

You could:

• Mount the local directory containing that Dockerfile.
• Mount the local Docker sock.
• Build that Nginx image from inside of container running this image.

docker run -v $(pwd):/app -v /var/run/docker.sock:/var/run/docker.sock start2/docker-compose-ansibl sh -c "cd /app/ && docker build -t custom-nginx ."

⁠Problem description

There is an official Docker image⁠ that contains the docker binary. And there is a Docker Compose image⁠.

But the Docker Compose image has docker-compose as the entrypoint.

So, it's not possible to run other commands on that image, like installing something, e.g. apt-get install -y curl.

And it's also not possible to run docker commands directly, e.g. docker login -u ci-user -p $CI_JOB_TOKEN $CI_REGISTRY.

This image allows running arbitrary commands like Bash scripts, docker commands and also Docker Compose commands like docker-compose build and docker-compose push.

As several Continuous Integration systems allow doing previous steps, like installing packages before running the actual main script, those steps could be used to install Docker Compose. But by downloading and installing Docker Compose every time, the builds would be slower.

For example, a very simple GitLab CI file .gitlab-ci.yml could look like:

# Do not use this file example
image: docker:latest

before_script:
  - apk add --no-cache py-pip
  - pip install docker-compose
  - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY

ci:
  script:
    - docker-compose build
    - docker-compose up -d
    - docker-compose exec -T tests run-tests.sh
    - docker-compose down -v
    - docker stack deploy -c docker-compose.prod.yml --with-registry-auth prod-example-com

But when the base image has to download and install Docker Compose every time, that's time added to the process. Specifically the lines in:

...

  - apk add --no-cache py-pip
  - pip install docker-compose

...

⁠This image's solution

This image includes Docker Compose and allows you to run any other arbitrary command.

So your GitLab CI .gitlab-ci.yml file could then look like:

image: start2/docker-compose-ansible

before_script:
  - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY

ci:
  script:
    - docker-compose build
    - docker-compose up -d
    - docker-compose exec -T tests run-tests.sh
    - docker-compose down -v
    - docker stack deploy -c docker-compose.prod.yml --with-registry-auth prod-example-com

And it would run faster as it doesn't have to install Docker Compose every time.

And you could start that initial GitLab Runner following the GitLab CI runner for CI/CD guide on DockerSwarm.rocks⁠.

The same would apply for Travis, Jenkins or whichever CI system you use.

⁠Release Notes

⁠Latest Changes

• Copied and adapted repo from Tiangolo⁠.

⁠License

This project is licensed under the terms of the MIT license.