docker-dev eases common tasks involving Docker and Docker Compose in development. Its primary feature is to namespace Docker Compose projects so that you can easily have one project for each branch in your repository.

Docker Compose projects are given a name, which default to that of the project directory. This name is then prefixed to the Docker resources (e.g., images, containers) created for the Docker Compose project.

docker-dev extends the project name to include the active branch name, and then proxies calls to docker-compose so that they refer to the new project name. For example, if your project is called "foo" and your active Git branch is "master", the Docker Compose project name will be set to "foo-master".

This tool is available on PYPI as docker-dev.

• Maintain isolated Docker Compose projects for branches of the same VCS repository, even if they all share the same path. This means that git checkout will play nice with docker-compose.
• Run host-level commands just before running docker-compose build. This is essential in some environments, such as Python where a *.egg-info directory must exist at the root of the project if you mount the path on the container to get instant code reload.
• Easily run your test suites and export their output to the host. For example, you can use this to expose your test reports to your Continuous Integration Service.

docker-dev proxies the docker-compose sub-commands build, up and down:

• docker-dev build will run all the pre-build hooks that you have installed (see below) and it'll also pull the latest version of any base images before actually building the images.
• docker-dev up ensures that you get new containers on each call.
• docker-dev down ensures that no trace of your project is left in Docker (inc. images, containers and volumes).

docker-dev test allows you to run test suites and export their output to the host system. It requires a Docker Compose file (testing.dc.yml by default) that defines all the services responsible for running the tests.

Each test service has to begin with "test-" and must place its output in /tmp/test-reports, as the contents of this directory will later be exported to the host. Here's an example of a Docker Compose file for testing:

version: "2"
services:
  test-main:
    build: "."
    command: "test-runner --output-dir=/tmp/test-reports"

To prevent a name clash, the suffix "-test" is added to the Docker Compose project name when run.

No traces are left in Docker after this command is run, not even when the tests fail.

This tool can be extended via the following types of plugins.

If your Docker Compose project is in a Git repository, docker-dev will append the active branch name to the name of the Docker Compose project. If you want to override this behaviour or add support for another VCS, you'd need to create a function that computes the name; e.g.:

def get_project_name(docker_compose_file_path):
    return 'suffix'

Finally, you have to register that function in your project's setup.py file as an entry point for the group docker_dev.project_name_generator. E.g.,

setup(
    name='your-distribution',
    entry_points={
        'docker_dev.project_name_generator': [
            'foo = your_package:get_project_name',
        ],
    },
)

To have routines executed at the host level before building the images, you can create a pre-build hook. For example:

def hook(docker_compose_file_path, project_name):
    run_some_commands()

This function then has to be registered as an entry point, under the group docker_dev.pre_build_hooks.

docker-dev will run all the installed pre-build hooks unconditionally.

As of this writing, only one plugin is available: docker-dev-python.

For an comprehensive and up-to-date description of the CLI, run docker-dev --help.