Docker instance sharing with boot2docker

README.md

Why we do that?

Because /var/run/docker.sock is not directly available on a machine running boot2docker.

How do we do that?

docker build -t shared-docker-env .

docker run -ti --rm -v ~/.boot2docker/certs/boot2docker-vm:/root/.docker -v $(which docker):/usr/bin/docker -e DOCKER_HOST=$DOCKER_HOST shared-docker-env

1. -v ~/.boot2docker/certs/boot2docker-vm:/root/.docker injects your boot2docker TLS certificates;
2. -v $(which docker):/usr/bin/docker injects the docker client in the container;
3. -e DOCKER_HOST=$DOCKER_HOST shares the docker daemon HTTP URL (eg: tcp://192.168.59.103:2376) – enclosed in the boot2docker VM.

Then the CMD ["docker", "--tlsverify", "ps"] statements ensures the connection is made through HTTP instead of the UNIX socket, implicitly using the certificates located in the /root/.docker folder.

Dockerfile

FROM busybox

CMD ["docker", "--tlsverify", "ps"]