diff --git a/doc/ci/docker/using_docker_build.md b/doc/ci/docker/using_docker_build.md index 0a2419b7ed2..22afcb9199d 100644 --- a/doc/ci/docker/using_docker_build.md +++ b/doc/ci/docker/using_docker_build.md @@ -164,6 +164,21 @@ not without its own challenges: - By default, `docker:dind` uses `--storage-driver vfs` which is the slowest form offered. To use a different driver, see [Using the overlayfs driver](#using-the-overlayfs-driver). +- Since the `docker:dind` container and the runner container don't share their + root filesystem, the job's working directory can be used as a mount point for + children containers. For example, if you have files you want to share with a + child container, you may create a subdirectory under `/builds/$CI_PROJECT_PATH` + and use it as your mount point (for a more thorough explanation, check [issue + #41227](https://gitlab.com/gitlab-org/gitlab-ce/issues/41227)): + + ```yaml + variables: + MOUNT_POINT: /builds/$CI_PROJECT_PATH/mnt + + script: + - mkdir -p "$MOUNT_POINT" + - docker run -v "$MOUNT_POINT:/mnt" my-docker-image + ``` An example project using this approach can be found here: https://gitlab.com/gitlab-examples/docker.