Docker git-crypt Alpine image

Git-crypt in Docker.

Forked from xueshanf/docker-git-crypt, with the following changes:

• Upgraded Alpine to 3.6
• Added GnuPG inside the container
• Removed source code from the container after building
• Added a user instead of using root inside the container
• Change CMD to an ENTRYPOINT
• Added Makefile for building
• Added labelschema labels to Dockerfile

You can use git-crypt container on systems that git-crypt packages aren't available, such as CoreOS, and it helps you avoid shared library dependency hell; this is what drove me here, as I was maintaining multiple, specific, old versions of openssl-1.0-compat on Arch Linux in order for git-crypt and Spotify to work.

The container exposes volume /repo, to which you can bind-mount a git repository.

Building the Image

Use make:

make build

This will build quay.io/lukebond/git-crypt:VERSION, where VERSION is specified in the Makefile (current v1.0.0).

Create a git-crypt shell wrapper

Ensure you have the image pulled locally:

$ docker pull quay.io/lukebond/git-crypt:v1.0.0

To make it easy to use, create a shell wrapper git-crypt, make it executable, and save it somewhere in your path (I put it in ~/bin).

Run the following commands from the root directory of your project that uses git-crypt.

If using shared key:

#!/bin/bash -e
exec docker run -it -v $(pwd):/repo -v /path/to/shared-git-crypt-key:/repo/.git/.git-crypt/keys/default quay.io/lukebond/git-crypt:v1.0.0 "$@"

If using gpg private key:

#!/bin/bash -e
exec docker run -it -v $(pwd):/repo -v ~/.gnupg:/home/gitcrypt/.gnupg quay.io/lukebond/git-crypt:v1.0.0 "$@"

Troubleshooting

If you have a password on your GPG key, you may see messages such as "No secret key". This is likely because you have a X dialog that pops up and asks for your password, which won't work inside the container without a bit of work. Instead, tell GPG to use the loopback pinentry mode:

In ~/.gnupg/gpg-agent.conf:

allow-loopback-pinentry

... and in `~/.gnupg/gpg.conf:

pinentry-mode loopback

According to the Arch Linux documentation, the latter may cause problems and it's best to pass the --pinentry-mode loopback command-line argument to the gpg command. Something that could be done in this Docker image by wrapping or aliasing the gpg command. Bear this in mind if you have issues.

Example usages

Make sure the above git-crypt wrapper command is in your command path.

• Command help

   $ git-crypt help
  

• List encrypted files:

   $ git-crypt status -e
  

• List unencrypted files

   $ git-crypt status -u
  

• Unlock encrypted files

   $ git-crypt unlock