docker-git is a unofficial docker image for a git client. docker-git is based on Alpine linux for simplicity and small footprint.
This image does not offer any services nor convenient entrypoints; This image sole purpose is to be used for CI deploy jobs, where the best deploy strategy is a git pull.
It could also be used interactively, but there is little benefit in doing so. I won't discuss details of how to archive that, but my sugestion is to write a simple bash-wrapper arround this image, like what is done for compose.