build git-crypt for alpine

[ghost]

Containerize git-crypt

Simple dockerfile that builds git-crypt for alpine linux and wraps it in a small container ~9MB.

Context

I recently started working with https://github.com/concourse/concourse and as a result needed a way to be able to decrypt and encrypt my repos without too much effort.

Problem Statement

Working with concourse introduced a restriction where every task is in a new container.
It simply made sense to create a base image that extended a small footprint ( like https://github.com/gliderlabs/docker-alpine ) and alpine does not contain an apk package for git-crypt. It was easy enough to build in-image and remove the utils leaving a alpine+git-crypt image.

Solution

Create an alpine image that has git-crypt already bundled.

Pending work

• Add to makefile target to build image
• Work with current checkout as compared to pulling from HEAD
• Pass version info via make

[spk]

Hi git-crypt is packaged on alpine https://pkgs.alpinelinux.org/package/edge/community/x86/git-crypt

[x-yuri]

These days building is done this way:

$ docker run --rm -it alpine:3.20
/ # apk add git build-base openssl-dev
/ # git clone https://github.com/AGWA/git-crypt
/ # cd git-crypt
/git-crypt # apk add curl
/git-crypt # curl 'https://gitlab.archlinux.org/archlinux/packaging/packages/git-crypt/-/raw/0.7.0-2/openssl-3.0.patch?ref_type=tags' \
  -o openssl-3.0.patch
/git-crypt # patch -p1 < openssl-3.0.patch
/git-crypt # make CXXFLAGS='-Wall -pedantic -Wno-long-long -O0 -g3'
/git-crypt # ./git-crypt --version