A simple Git LFS server implementation in Dart

Overview

Git LFS client (git-lfs or git lfs command) requires a dedicated LFS-content server (not the Git server!) in order to download/upload binary files. There will be an issue if you try to use a mirror of a Git repo with LFS-enabled: git-lfs#1338. This Git LFS server implementation solves that problem.

There are other implementations that you can look for if you're not working with Git mirrors.

Quick Reference

• Maintained by: Khoa

• Supported architectures: amd64, arm64

• Documentation: git-lfs-server Wiki.

• Where to get help: git-lfs-server Discussions

Benefit

There are two important reasons to set up a Git server for mirroring with LFS-enabled:

• To save bandwidth on the connection to the remote server, especially if the repositories are big.
• Team members don't have access to the remote server, but your Git server can.

Limitations

• Only download operation is supported. You cannot upload binary files.
• LFS contents in the mirror are not fetched automatically by this tool.

Quick Start

For the sake of simplicity, I have created a Docker Hub repository with the images ready to use. Assumed that you have the same problem as in git-lfs#1338 (There's a picture in it if you like graphical presentation). Although, for a smoothly experience, I would add some more details:

• Mirrors will be accessible via SSH, i.e., you can do git clone git@GIT_SERVER:MIRROR_REPO.git, or git clone ssh://git@GIT_SERVER:PORT/MIRROR_REPO.git
• Self-signed certificate: we need a .key file, a .crt file, a .pem file. Follow this guide to create one.
• You will need some automation to fetch latest Git references and LFS contents from the far repositories, in case the far repositories are newer than the mirrors.
• Far remote is LFS-enabled.
• Near remote has Docker installed.

If all requirements are satisfied, let us proceed step-by-step

1. Pull the image: docker pull khoa10/amz-git-mirroring:latest
2. There must be a folder named certificates with 3 files: git-lfs-server.key, git-lfs-server.cert, git-lfs-server.pem. Create a volume to store the certificate:

$ ls certificates
git-lfs-server.crt  git-lfs-server.key  git-lfs-server.pem
$ docker volume create --name git-lfs-server-certs
$ docker run --rm -v $PWD:/source -v git-lfs-server-certs:/dest -w /source alpine cp "certificates/git-lfs-server.key" "certificates/git-lfs-server.crt" "certificates/git-lfs-server.pem" /dest

1. With your mirrors are located at $INSERT_YOUR_PATH_HERE, create the container:

docker run \
--detach \
--env GIT_LFS_SERVER_URL="https://$INSERT_URL_HERE:8443" \
--mount type=bind,src=$INSERT_YOUR_PATH_HERE,dst=/source \
--mount type=volume,src=git-lfs-server-certs,dst=/etc/git-lfs-server/certificates \
-p 8443:8443 \
-p 2022:22 \
khoa10/amz-git-mirroring

Now, your Git server is available at ssh://git@<NEAR_REMOTE>:2022 and the LFS server is available at https://<NEAR_REMOTE>:8443. Because we're using self-signed certificate, Git client must either ignore TLS verification or trust the certificate you created. To ignore TLS verification:

git config --global http.https://<NEAR_REMOTE>:8443.sslverify false

For better experience, client should configure to download from near and push to far:

git config --global url.ssh://git@<NEAR_REMOTE>:2022.insteadOf ssh://git@<FAR_REMOTE>
git config --global url.ssh://git@<FAR_REMOTE>.pushInsteadOf ssh://git@<NEAR_REMOTE>:2022

License

MIT license