Docker in Docker

Orchestrating Docker agents from inside Docker

This page is up to date, and intended for version 1.0 of the Coral Server and Coral Studio.

In order to allow Coral Server to spin up containers while being inside a Docker container itself, we need to mount the host’s Docker socket into our container.

Since Docker behaves differently on each platform - how to do this varies:

Linux

Mounting /var/run/docker.sock should be enough to give the server the ability to spin up containers.

docker run -v /var/run/docker.sock:/var/run/docker.sock ...

macOS

We recommend you install colima for a nicer experience. With colima, you can mount ~/.colima/docker.sock:

docker run -v "~/.colima/docker.sock:/var/run/docker.sock" ...

Without colima, you can mount ~/.docker/run/docker.sock to the container:

docker run -v "~/.docker/run/docker.sock:/var/run/docker.sock" ...

Windows

Mount //var/run/docker.sock:

docker run -v "//var/run/docker.sock://var/run/docker.sock" ...

If that doesn’t work, mount //./pipe/docker_engine:

docker run `
    -v "//./pipe/docker_engine://./pipe/docker_engine" `
    ...