Git alpine

Minimal alpine image, that can interact with git

Build

docker build -t alpine-git .

Run

Create a keys folder, containing your private id_rsa ssh-key and a known_hosts file for the Git server you're interacting with, and mount it to the .ssh folder of the non-privileged-user

Create a git folder and mount it into the /git path.

Pass the repository url as the GIT_REPO_URL environment variable.

docker run --rm \
    -e GIT_REPO_URL="git@bitbucket.org:myteam/myproject.git" \
    -v $PWD/keys:/home/non-privileged/.ssh \
    -v $PWD/git:/git \
    alpine-git [-- <optional command>]

Where [-- <optional parameter>] could be -- git checkout my-branch or --version (the preceding -- aren't necessary when it's only a single command.)

Testing

Generate ssh-keys with ssh-keygen -q -t rsa -N '' -f id_rsa, and put the private-key into the keys directory.

Add a known_hosts file as well, using ssh-keyscan bitbucket.org (you can run this in an alpine image as well, after installing openssh-client)

Why?

The official alpine/git uses the git command as the ENTRYPOINT, but it doesn't unfold environment variables; sh does.

A single string? I haven't had luck specifying it as either,

ENTRYPOINT [ 'sh', '-c' 'git' ]
CMD [ 'clone', '$GIT_REPO_URL'  ]

or

ENTRYPOINT [ 'sh', '-c' ]
CMD [ 'git', 'clone', '$GIT_REPO_URL'  ]