git-remote-update

This library exposes a single object to watch for a remote git repo changes, and to update a local git repo. It is intended to work well with github.

Its process is quite simple, and was not designed to handle out-of-the-box situations where the updated code has received commits from another source than the one being watched. By the way, it is quite generic so it probably can be easily used to do so.

The git client used is the excellent nodegit.

Install

npm install git-remote-update --save

Use

const GitWatcher = require('git-remote-update');

Intended use case

You own a server, which hosts a process (a web service, a bot, etc).

You want to update the code on your server by using github (or any other remote git repo). Each time you push a change on the dedicated github repo from your personal computer, you want the server to update its code.

Do the following:

• Create a repo on github and put your code in (including git-remote-update handlers)
• Clone the repo on your server
• On your server, start your script with forever; this is a client that will restart your script if it ends
• On your code, there should be something like that, which will simply kill your script after an update is done (and forever will gently restart it):

const gw = new GitWatcher({
    git: './.git'
});

gw.on('ready', () => gw.watch());
gw.on('newerCommit', () => gw.update());
gw.on('updated', () => process.exit());

API

This library exposes the GitWatcher class. GitWatcher is a simple event emitter.

new GitWatcher(config)

The config is an object with the following values:

Option	Description	Default
git	Location of the git file (relative to the script entry point, or fullpath)	'./.git'
remoteBranch	The branch to get update from	'origin/master'
localBranch	The branch to be updated	'master'

fetch()

Look once at the remote branch.

watch(interval)

Call fetch each interval (in ms, default 30000), so it can look for changes on the repo over time. Returns a function that you can call to stop watching.

update()

Performs merge from remote branch to localBranch.

on(event, callback)

Call the callback function when the corresponding event is fired.

Event	Description	Callback parameters
ready	The object is ready, so you can call fetch or watch	-
comparison	A comparison is done, so you can make your own comparison function	remoteCommit, localCommit
newerCommit	There is a more recent commit on the remote branch	remoteCommit, localCommit
differentCommit	The last commit id on the remote branch is different from the local	remoteCommit, localCommit
updated	Update is done	-
error	An error happened	error

remoteCommit and localCommit are commit objects from nodegit, you can have documentation for them on nodegit website.