git-nomad

Synchronize work-in-progress git branches in a light weight fashion. Motivation:

• You frequently work on the same repository from multiple machines, like a laptop and a desktop.
• You frequently rewrite history and use short understandable-by-only-you branch names, making pushing regular branches to git remotes cumbersome.
• You want all the efficiency and synchronization benefits of having a git clone available, meaning external syncing tools like Dropbox or network mounts are right out.
• You want this synchronization to work out-of-the-box with popular third party remote hosts like GitHub.

Usage

Install git-nomad to make it available on your $PATH. Assume you're hacking away with your usual git workflow:

console rraval@desktop:~/git-nomad$ git checkout -b feature rraval@desktop:~/git-nomad$ touch new_file rraval@desktop:~/git-nomad$ git add . rraval@desktop:~/git-nomad$ git commit -m "new file"

Whenever you like, you can push the state of your local branches with:

```console

Synchronizes with a remote called origin by default.

See --help for overriding this explicitly.

rraval@desktop:~/git-nomad$ git nomad sync Pushing local branches to origin... 3s Fetching branches from origin... 0s Listing branches at origin... 3s

desktop refs/nomad/desktop/feature -> c340cd55853339e4d039746495cdb80cd9e46123 refs/nomad/desktop/master -> 267719fb8448cc1cbef2c35a638610573779f2ac ```

At some future point, you wish to pick up development on a different machine:

```console rraval@laptop:~/git-nomad$ git nomad sync Pushing local branches to origin... 2s Fetching branches from origin... 1s Listing branches at origin... 2s

desktop refs/nomad/desktop/feature -> 1a101799507ba67d822b97105aafa0ac91ce5183 refs/nomad/desktop/master -> 267719fb8448cc1cbef2c35a638610573779f2ac laptop refs/nomad/laptop/master -> 267719fb8448cc1cbef2c35a638610573779f2ac ```

Which prints out refs to use to pick up where you left off:

```console rraval@laptop:~/git-nomad$ git checkout -b feature refs/nomad/desktop/feature

Hack away where you left off on desktop

```

Let's say that the laptop machine is where development is happening now, so you go back to desktop to throw away the now outdated branch:

```console rraval@desktop:~/git-nomad$ git checkout master rraval@desktop:~/git-nomad$ git branch -D feature Deleted branch feature (was 1a10179).

rraval@desktop:~/git-nomad$ git nomad sync Pushing local branches to origin... 2s Fetching branches from origin... 1s Listing branches at origin... 0s Pruning branches at origin... 0s Delete refs/nomad/desktop/feature (was 1a101799507ba67d822b97105aafa0ac91ce5183)... 0s

desktop refs/nomad/desktop/master -> 267719fb8448cc1cbef2c35a638610573779f2ac laptop refs/nomad/laptop/feature -> dedf3f9d3ad279a401877b351c3ec13aa47cbbd4 refs/nomad/laptop/master -> 267719fb8448cc1cbef2c35a638610573779f2ac ```

If you'd like to stop using git-nomad and clean up all the refs it has created:

```console

See also the purge --host option.

rraval@desktop:~/git-nomad$ git nomad purge --all Fetching branches from origin... 1s Listing branches at origin... 0s Pruning branches at origin... 2s Delete refs/nomad/desktop/master (was 267719fb8448cc1cbef2c35a638610573779f2ac)... 0s Delete refs/nomad/laptop/feature (was dedf3f9d3ad279a401877b351c3ec13aa47cbbd4)... 0s Delete refs/nomad/laptop/master (was 267719fb8448cc1cbef2c35a638610573779f2ac)... 0s ```

How it works

Git is unabashedly a content-addressed filesystem that manipulates blob, tree, and commit objects. Layered on top of this is a half decent version control system, though this claim is contentious at best.

Git branches are implemented on top of a more general scheme called refs, where the local branch master is simply the commit pointed to by refs/heads/master. Git reserves a few hierarchies for its own use:

• refs/heads/* represent local branches.
• refs/tags/* represent tags.
• refs/remotes/* represent remote branches.

git-nomad works directly with refs to implement its own light weight synchronization scheme:

1. Push local refs/heads/* to remote refs/nomad/{user}/{host}/*. This allows multiple users on multiple hosts to all use git-nomad on the same remote without overwriting data.
2. Fetch remote refs/nomad/{user}/* to local refs/nomad/*. This makes all the host refs for a given user available in a local clone.
3. Prune local refs/nomad/* refs where the corresponding branch has been deleted.

Using refs like this has advantages:

• You only pay the storage cost for the content unique to the branch. The bulk of repository history is shared!
• As refs get cleaned up, gits automatic garbage collection should reclaim space.
• Since these refs are under a separate refs/nomad hierarchy, they are not subject to the usual fast-forward only rules.

Installation

On Linux or Mac OS X

Releases on GitHub have prebuilt binary assets: https://github.com/rraval/git-nomad/releases

1. Download the latest version for your OS.
2. gunzip the downloaded file.
3. Place the binary somewhere in your $PATH.
4. Check that things work with git nomad --version.

On NixOS / via Nix

Install via nixpkgs:

$ nix-env --install git-nomad

From source

If you have cargo available:

$ cargo install git-nomad

Bleeding Edge

Via nix run

Nix can build and run the binary directly from GitHub via:

$ nix run github:rraval/git-nomad

Contributing

There are a few ways to make this project better:

1. Try it and file issues when things break. Use the -vv flag to capture all information about the commands that were run.
2. Build packages for various operating systems.