gitreceive

Creates an ssh+git user that accepts on the fly repository pushes and triggers a hook script.

Push code anywhere. Extend your Git workflow.

gitreceive dynamically creates bare repositories with a special pre-receive hook that triggers your own general gitreceive hook giving you easy access to the code that was pushed while still being able to send output back to the git user.

Requirements

You need a Linux server with git and sshd installed.

Installing

On your server, download https://raw.github.com/progrium/gitreceive/master/gitreceive to a location on your $PATH and make it executable.

Using gitreceive

Set up a git user on the server

This automatically makes a user and home directory if it doesn't exist.

$ sudo gitreceive init
Created receiver script in /home/git for user 'git'.

You use a different user by setting GITUSER=somethingelse in the environment before using gitreceive.

Modify the receiver script

As an example receiver script, it will POST all the data to a RequestBin:

$ cat /home/git/receiver
#!/bin/bash
URL=http://requestb.in/rlh4znrl
echo "----> Posting to $URL ..."
curl \
  -X 'POST' \
  -F "repository=$1" \
  -F "revision=$2" \
  -F "username=$3" \
  -F "fingerprint=$4" \
  -F contents=@- \
  --silent $URL

The username is just a name associated with a public key. The fingerprint of the key is sent so you can authenticate against the public key that you may have for that user.

Commands do not have access to environment variables from the /etc/profile directory, so if you need access to them, you will need to maually source /etc/profile - or any other configuration file - within your receiver script.

The repo contents are streamed into STDIN as an uncompressed archive (tar file). You can extract them into a directory on the server with a line like this in your receiver script:

mkdir -p /some/path && cat | tar -x -C /some/path

Create a user by uploading a public key from your laptop

We just pipe our local SSH key into the gitreceive upload-key command via SSH:

$ cat ~/.ssh/id_rsa.pub | ssh you@yourserver.com "sudo gitreceive upload-key <username>"

The username argument is just an arbitrary name associated with the key, mostly for use in your system for auth, etc.

gitreceive upload-key will authorize this key for use on the $GITUSER account on the server, and use the SSH "forced commands" syntax in the remote .ssh/authorized_keys file, causing the internal gitreceive run command to be called when this key is used with the remote git account. This allows us to intercept the git requests and set up a pre-receive hook to run on the repo, which triggers the custom receiver script.

Add a remote to a local repository

$ git remote add demo git@yourserver.com:example

The repository example will be created on the fly when you push.

Push!!

$ git push demo master
Counting objects: 5, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (3/3), done.
Writing objects: 100% (3/3), 332 bytes, done.
Total 3 (delta 1), reused 0 (delta 0)
----> Receiving progrium/gitreceive.git ... 
----> Posting to http://requestb.in/rlh4znrl ...
ok
To git@gittest:progrium/gitreceive.git
   59aa541..6eafb55  master -> master

The receiver script did not attempt to silence the output of curl, so the respones of "ok" from RequestBin is shown. Use this to your advantage! You can even use chunked-transfer encoding to stream back progress in realtime if you wanted to keep using HTTP. Alternatively, you can have the receiver script run any other script on the server.

Handling submodules

Submodules are not included when you do a git push, if you want them to be part of your workflow, have a look at Handling Submodules.

So what?

You can use gitreceive not only to trigger code on git push, but to provide feedback to the user and affect workflow. Use gitreceive to:

• Put a git push deploy interface in front of App Engine
• Run your company build/test system as a separate remote
• Integrate custom systems into your workflow
• Build your own Heroku
• Push code anywhere

I used to work at Twilio. Imagine pushing a repo with a TwiML file to a gitreceive repo with a phone number for a name. And then it runs that TwiML on Twilio and shows you the result, all from the git push.

Big Thanks

DotCloud, DigitalOcean

License

MIT