dcind (Docker-Compose-in-Docker)
Versioning
This repository and corresponding images on Docker Hub follow the semantic versioning rules. It is advised to not rely on the latest tag when using amidos/dcind image in your CI pipelines. Consider using a specific version, like amidos/dcind:1.
Usage
Use this Dockerfile to build a base image for your integration tests in Concourse CI. Alternatively, you can use a ready-to-use image from the Docker Hub: amidos/dcind. The image is Alpine based.
Here is an example of a Concourse job that uses amidos/dcind image to run a bunch of containers in a task, and then runs the integration test suite. You can find a full version of this example in the example directory.
Note that docker-lib.sh has bash dependencies, so it is important to use bash in your task.
- name: integration
plan:
- aggregate:
- get: code
params: {depth: 1}
passed: [unit-tests]
trigger: true
- get: redis
params: {save: true}
- get: busybox
params: {save: true}
- task: Run integration tests
privileged: true
config:
platform: linux
image_resource:
type: docker-image
source:
repository: amidos/dcind
inputs:
- name: code
- name: redis
- name: busybox
run:
path: bash
args:
- -exc
- |
source /docker-lib.sh
start_docker
# Strictly speaking, preloading of Docker images is not required.
# However, you might want to do this for a couple of reasons:
# - If the image comes from a private repository, it is much easier to let Concourse pull it,
# and then pass it through to the task.
# - When the image is passed to the task, Concourse can often get the image from its cache.
docker load -i redis/image
docker tag "$(cat redis/image-id)" "$(cat redis/repository):$(cat redis/tag)"
docker load -i busybox/image
docker tag "$(cat busybox/image-id)" "$(cat busybox/repository):$(cat busybox/tag)"
# This is just to visually check in the log that images have been loaded successfully
docker images
# Run the container with tests and its dependencies.
docker-compose -f code/example/integration.yml run tests
# Cleanup.
# Not sure if this is required.
# It's quite possible that Concourse is smart enough to clean up the Docker mess itself.
docker volume rm $(docker volume ls -q)