Rerun

Launches your app, then watches the filesystem. If a relevant file changes, then it restarts your app.

Currently only *.rb files are watched, anywhere under the current directory (.). This is pretty lame so it will change soon.

If you’re on Mac OS X, it uses the built-in facilities for monitoring the filesystem, so CPU use is very light.

If you have “growlcmd” available on the PATH, it sends notifications to growl in addition to the console.

Installation:

    sudo gem install rerun

or…

    gem sources -a http://gems.github.com/
    sudo gem install alexch-rerun

(The github way isn’t working yet for some reason. Maybe I have to wait for cron to run or something.)

Usage:

    rerun [options] cmd

For example, if you’re running a Sinatra app whose main file is app.rb:

    rerun app.rb

Or if you’re running a Rack app that’s configured in config.ru but you want to override its port:

    rerun "thin start --port=4000 -R config.ru"

Options:

Only –version and –help so far.

To Do:

Allow arbitrary sets of directories and file types, possibly with “include” and “exclude” sets
“.rerun” file to specify options per project or in $HOME.
Test on Windows and Linux.

Other projects that do similar things

Restartomatic: http://github.com/adammck/restartomatic

Shotgun: http://github.com/rtomayko/shotgun

Why would I use this instead of Shotgun?

Shotgun does a “fork” after the web framework has loaded but before your application is loaded. It then loads your app, processes a single request in the child process, then exits the child process.

Rerun launches the whole app, then when it’s time to restart, uses “kill” to shut it down and starts the whole thing up again from scratch.

So rerun takes somewhat longer than Shotgun to restart the app, but does it much less frequently. And once it’s running it behaves more normally and consistently with your production app.

Also, Shotgun reloads the app on every request, even if it doesn’t need to. This is fine if you’re loading a single file, but my web pages all load other files (CSS, JS, media) and that adds up quickly. The developers of shotgun are probably using caching or a front web server so this doesn’t affect them too much.

YMMV!

Why did you write this?

I’ve been using Sinatra and loving it. In order to simplify their system, the Rat Pack just took out auto-reloading. I approve of this: a web application framework should be focused on serving requests, not on munging Ruby ObjectSpace. But I still wanted automatic reloading during development. Shotgun wasn’t working for me (see above) so I spliced Rerun together out of .

Credits

Rerun: Alex Chaffee, [email protected], http://github.com/alexch/

Based upon and/or inspired by:

Shotgun: http://github.com/rtomayko/shotgun

Rspactor: http://github.com/mislav/rspactor

FileSystemWatcher: http://paulhorman.com/filesystemwatcher/

License

Open Source MIT License. See “LICENSE” file.