http://github.com/alexch/rerun
Rerun launches your program, then watches the filesystem. If a relevant file changes, then it restarts your program.
Rerun works for both long-running processes (e.g. apps) and short-running ones (e.g. tests). It's basically a no-frills command-line alternative to Guard, Shotgun, Autotest, etc. that doesn't require config files and works on any command, not just Ruby programs.
Rerun's advantage is its simple design. Since it uses exec
and the standard
Unix SIGINT
and SIGKILL
signals, you're sure the restarted app is really
acting just like it was when you ran it from the command line the first time.
By default only *.{rb,js,css,scss,sass,erb,html,haml,ru}
files are watched.
Use the --pattern
option if you want to change this.
As of version 0.7.0, we use the Listen gem, which tries to use your OS's built-in facilities for monitoring the filesystem, so CPU use is very light.
Rerun does not work on Windows. Sorry, but you can't do much relaunching without "fork".
gem install rerun
("sudo" may be required on older systems, but try it without sudo first.)
If you are using RVM you might want to put this in your global gemset so it's available to all your apps. (There really should be a better way to distinguish gems-as-libraries from gems-as-tools.)
rvm @global do gem install rerun
rerun [options] [--] cmd
For example, if you're running a Sinatra app whose main file is app.rb
:
rerun ruby app.rb
If the first part of the command is a .rb
filename, then ruby
is
optional, so the above can also be accomplished like this:
rerun app.rb
Rails doesn't automatically notice all config file changes, so you can force it to restart when you change a config file like this:
rerun --dir config rails s
Or if you're using Thin to run a Rack app that's configured in config.ru
but you want it on port 4000 and in debug mode, and only want to watch
the app
subdirectory:
rerun --dir app -- thin start --debug --port=4000 -R config.ru
The --
is to separate rerun options from cmd options. You can also
use a quoted string for the command, e.g.
rerun --dir app "thin start --debug --port=4000 -R config.ru"
Rackup can also be used to launch a Rack server, so let's try that:
rerun -- rackup --port 4000 config.ru
Want to mimic autotest? Try
rerun -x rake
or
rerun -cx rspec
And if you're using Spork with Rails, you need to restart your spork server whenever certain Rails environment files change, so why not put this in your Rakefile...
desc "run spork (via rerun)"
task :spork do
sh "rerun --pattern '{Gemfile,Gemfile.lock,spec/spec_helper.rb,.rspec,spec/factories/**,config/environment.rb,config/environments/test.rb,config/initializers/*.rb,lib/**/*.rb}' -- spork"
end
and start using rake spork
to launch your spork server?
(If you're using Guard instead of Rerun, check out guard-spork for a similar solution.)
How about regenerating your HTML files after every change to your Erector widgets?
rerun -x erector --to-html my_site.rb
Use Heroku Cedar? rerun
is now compatible with foreman
. Run all your
Procfile processes locally and restart them all when necessary.
rerun foreman start
--dir
directory to watch (default = ".")
--pattern
glob to match inside directory. This uses the Ruby Dir glob style -- see http://www.ruby-doc.org/core/classes/Dir.html#M002322 for details.
By default it watches files ending in: rb,js,css,scss,sass,erb,html,haml,ru
.
It also ignores directories named .rbx .bundle .git .svn log tmp vendor
and files named .DS_Store
.
--clear
(or -c) clear the screen before each run
--exit
(or -x) expect the program to exit. With this option, rerun checks the return value; without it, rerun checks that the launched process is still running.
Also --version and --help, naturally.
If you have growlnotify
available on the PATH
, it sends notifications to
growl in addition to the console.
Download growlnotify here now that Growl has moved to the App Store.
While the app is (re)running, you can make things happen by pressing keys:
- r -- restart (as if a file had changed)
- c -- clear the screen
- x or q -- exit (just like control-C)
- Cooldown (so if a dozen files appear in a burst, say from 'git pull', it only restarts once)
- If the last element of the command is a
.ru
file and there's no other command then userackup
- Exclude files beginning with a dot, unless the pattern explicitly says to include them
- Allow multiple sets of directories and patterns
- --exclude pattern
- ".rerun" file to specify options per project or in $HOME.
- Test on Linux.
- On OS X, use a C library using growl's developer API http://growl.info/developer/
- Use growl's AppleScript or SDK instead of relying on growlnotify
- "Failed" icon
- Get Rails icon working
- Figure out an algorithm so "-x" is not needed (if possible)
- Specify (or deduce) port to listen for to determine success of a web server launch
- Make sure to pass through quoted options correctly to target process [bug]
- Make it work on Windows, like Guard now does. See
- Optionally do "bundle install" before and "bundle exec" during launch
- Restartomatic: http://github.com/adammck/restartomatic
- Shotgun: http://github.com/rtomayko/shotgun
- Rack::Reloader middleware: http://github.com/rack/rack/blob/5ca8f82fb59f0bf0e8fd438e8e91c5acf3d98e44/lib/rack/reloader.rb
- The Sinatra FAQ has a discussion at http://www.sinatrarb.com/faq.html#reloading
- Kicker: http://github.com/alloy/kicker/
- Watchr: https://github.com/mynyml/watchr
- Guard: http://github.com/guard/guard
- Autotest: https://github.com/grosser/autotest
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 if your web pages all load other files (CSS, JS, media) then that adds up quickly. (I can only assume that the developers of shotgun are using caching or a front web server so this isn't a pain point for them.)
And hey, does Shotgun reload your Worker processes if you're using Foreman and a Procfile? I'm pretty sure it doesn't.
YMMV!
Rack::Reloader is certifiably beautiful code, and is a very elegant use of Rack's middleware architecture. But because it relies on the LOADED_FEATURES variable, it only reloads .rb files that were 'require'd, not 'load'ed. That leaves out (non-Erector) template files, and also, at least the way I was doing it, sub-actions (see this thread).
Rack::Reloader also doesn't reload configuration changes or redo other things that happen during app startup. Rerun takes the attitude that if you want to restart an app, you should just restart the whole app. You know?
Guard is very powerful but requires some up-front configuration. Rerun is meant as a no-frills command-line alternative requiring no knowledge of Ruby nor config file syntax.
I've been using Sinatra and loving it. In order to simplify their system, the Rat Pack just removed auto-reloading from Sinatra proper. I approve of this: a web application framework should be focused on serving requests, not on munging Ruby ObjectSpace for dev-time convenience. But I still wanted automatic reloading during development. Shotgun wasn't working for me (see above) so I spliced Rerun together out of code from Rspactor, FileSystemWatcher, and Shotgun -- with a heavy amount of refactoring and rewriting.
Rerun: Alex Chaffee, mailto:alex@stinky.com, http://github.com/alexch/
Based upon and/or inspired by:
- Shotgun: http://github.com/rtomayko/shotgun
- Rspactor: http://github.com/mislav/rspactor
- (In turn based on http://rails.aizatto.com/2007/11/28/taming-the-autotest-beast-with-fsevents/ )
- FileSystemWatcher: http://paulhorman.com/filesystemwatcher/
- David Billskog billskog@gmail.com
- Jens B https://github.com/dpree
- Andrés Botero https://github.com/anbotero
- Dreamcat4
- v0.7.0
- uses Listen gem (which uses rb-fsevent for lightweight filesystem snooping)
Open Source MIT License. See "LICENSE" file.