Git With Me

I have a Git repository and I want to collaborate with others. We do not have a public server, and do not wish to use existing hosting services.

git withme provides a way for a single host to invite numerous peers with short, one-time secure codes. The peers connect directly via Dilated Magic Wormhole channels, allowing collaborators to git clone git://localhost/<repo-name>.

• Git: https://git.sr.ht/~meejah/git-withme
• Releases: https://pypi.org/project/git-withme/

Motivational Example

I have created a Git repository:

$ mkdir ~/src/gwm
$ cd ~/src/gmw
$ echo "Git With Me" > README
$ git add README
$ git commit -m "begin"

Now chatting with a friend, I invite them to collaborate. In its own shell, I run the hosting service; this will connect to the public Magic Wormhole mailbox server.

$ cd ~/src/gwm
$ git withme
Hosting /home/meejah/src/gwm (via bare repo /tmp/tmpx_y7q2iq/gitwithme_remote)
 ╭───────────────────────────────────────────────────────────────╮
 │ Hosting: /home/mike/src/git-withme                            │
 │ Git WithMe is now running. To push code to all peers, use:    │
 │     git push gitwithme                                        │
 │ ...and to receive code from a peer who has pushed, use:       │
 │     git pull gitwithme main                                   │
 │ The temporary bare repository we created will be deleted when │
 │ this process is terminated.                                   │
 │                                                               │
 │ N -- create new peer                                          │
 │ Q -- quit, terminate all peers                                │
 ╰───────────────────────────────────────────────────────────────╯
                      Peers
 ┌────────────────────────────────────────────┐
 │ Invite code: 4-quux-foo                    │
 │ run "git-withme accept 4-quux-foo" to join │
 └────────────────────────────────────────────┘

I now send the code 4-quux-foo to my friend. On their computer, they run the "accept" command (with the secret code) to begin collaborating.

$ git withme --repo ~/src/gwm accept 4-quux-foo
welcome ws://relay.magic-wormhole.io:4000/v1
Peer has connected.
  git:
  git: Cloning into '~/src/gwm'...
  git:
You can now use normal git commands in ~/src/gwm
"git pull": update from the host
"git push": push changes to the host

Meanwhile, I should see something like this on my side:

┌──────────────────────────────────────────────────────┐
│ Connected (for 58 seconds). 🙂 (last 58 seconds ago) │
└──────────────────────────────────────────────────────┘

As long as both of these shells -- the one on my computer, and the one on my friend's -- remain running they forward end-to-end encrypted traffic between our two computers. This means that my friend can pull (and push) code; we can use Git somewhat normally.

When the host terminates, the bare repository in $TMPDIR is removed.

One-Time Codes

Malicious actors (even the Mailbox server, if malicious or compromised) get a single guess at breaking the code; if they are wrong, the mailbox is destroyed and the legitimate recipient will notice (they get a "crowded" error). This gives us an identity-free, long-lived connection -- so long as we keep our shells running, we can put our laptops to sleep or otherwise move networks (note that if both sides are disconnected for more than 10 minutes, the connection will be terminated).

How to Install

git withme is a Git extension written in Python. To "install" it, the git-withme script needs to be somewhere on your PATH (for git withme to work).

I recommend using a "virtualenv" or "venv" to install into, or you can try pip install --user git-withme if that works for your platform. For a "venv":

$ python -m venv ~/gwm-venv
$ ~/gwm-venv/bin/pip install git+https://git.sr.ht/~meejah/git-withme
$ export ~/gwm-venv/bin:$PATH
$ git withme --help