ladbit/docker-r10k repository overview

docker run -v /your/codedir:/etc/puppetlabs/code -e REPOSITORY="https://github.com/someone/control-repo.git" -e GITHUB_USER="someuser" -e GITHUB_PASSWORD="somepassword" grahamgilbert/r10k

export PRIVATE_KEY="$(cat /path/to/your/key)"
docker run -v /your/codedir:/etc/puppetlabs/code -e REPOSITORY="[email protected]:someone/control-repo.git" -e PRIVATE_KEY="$PRIVATE_KEY" grahamgilbert/r10k