shotgun(1) - Linux man page
Name
shotgun - reloading rack development serverSynopsis
shotgun [options] [rackup-file]Description
When no rackup-file is given, shotgun uses the config.ru file in the current working directory.
Options
Shotgun runs at http://127.0.0.1:9393 by default. The following options control server behavior:- -E, --env=environment
- Sets the RACK_ENV environment variable to environment and selects the default set of utility middleware. When environment is 'development', shotgun inserts the Rack::Lint and Rack::CommonLogger middleware components; when environment is 'production' or 'deployed', Rack::CommonLogger is inserted; otherwise, no utility middleware are inserted.
- -P, --public=path
- Serve requests for static files that exist under path from the shotgun master process without forking a worker process. This option is automatically enabled when a ./public directory is detected, but can be configured explicitly for non-conventional static file directory locations.
- Setting this option appropriately can severely improve overall page load times for applications with many static assets.
- -s, --server=mongrel|webrick|thin|other
- The Rack server handler implementation used to serve requests. Supported values include: mongrel, webrick, and thin. By default, shotgun first tries to use mongrel and falls back to webrick if mongrel is not available.
- -o, --host=addr
- The hostname or address of the interface the HTTP server should bind to. Default: 127.0.0.1.
- -p, --port=port
- The port the HTTP server should bind to. Default: 9393.
- -O, --browse
- Open browser at http://host:port/ immediately after the server is started.
Ruby environment related options:
- -r, --require library
- Require library before loading the application and starting the server. This can be used to load a portion of the application code in the master process so it doesn't need to be loaded in the child. See PRELOADING][] for more information on this approach.
- -e, --eval command
- Evaluate arbitrary command within the shotgun master Ruby interpreter. command is evaluated as program arguments are parsed. Multiple -e arguments are allowed.
- -d, --debug
- Turns on debug mode. $DEBUG will be set true.
- -w, --warn
- Enable verbose mode without printing version message at the beginning. It sets the $VERBOSE variable to true.
- -I, --include path
- Add path to the Ruby load path ($LOAD_PATH). May be used more than once.
Miscellaneous:
- -h, --help
- Show usage message and exit.
- --version
- Show the Rack version and exit.
Preloading
It's possible to load support libraries and portions of the application in the shotgun master process to reduce the amount of work that needs to be done for each request in worker processes. There's two ways of accomplishing this: either by specifying one or more --require (-r) arguments or through the use of a shotgun.rb file.During start up, shotgun looks for a shotgun.rb or config/shotgun.rb file. If either file is found, it's loaded into the shotgun master process. Code at the top-level of the shotgun.rb is run once on startup, so just require whatever you want to preload. It's also possible to register callbacks to run before each request in either the master or child worker process:
- after_fork { stuff }
- Run stuff in the shotgun child worker process immediately after forking. Any files or socket connections opened in the master process should be closed / re-established by an after_fork block.
- before_fork { stuff }
- Run stuff in the shotgun master process on each request before forking the child worker process. This is typically less useful than after_fork, but provided for completeness.
Example config/shotgun.rb file from the main github.com rails project:
- # make sure the load path includes RAILS_ROOTENV['RAILS_ROOT'] ||= File.expand_path('../..', __FILE__)$:.unshift ENV['RAILS_ROOT']# bring in the base rails environment and some librariesrequire 'config/environment'require 'google-charts'require 'aws-s3'# disable Rails's built in class reloadingRails.configuration.cache_classes = true# reset database and redis connections in workersafter_fork do ActiveRecord::Base.establish_connection CHIMNEY.client = $redisend
Installing
Shotgun is distributed as a gem package at rubygems.org:- http://rubygems.org/gems/shotgun
gem install shotgun
The rack package is required. The mongrel package is recommended.
Contributing
Fork and report issues at github.com:http://github.com/rtomayko/shotgun/
git clone git://github.com/rtomayko/shotgun.git
Version History
Version 0.8 (2010 June 24)
- http://github.com/rtomayko/shotgun/compare/0.7...0.8
- Preloading support. The shotgun.rb or config/shotgun.rb file is loaded at startup and may require libraries and register callbacks for fork events. See the section on PRELOADING.
- Fix starting with the Thin handler (shotgun -s thin)
- Actually include the shotgun(1) roff manual.
Version 0.7 (2010 June 22)
- http://github.com/rtomayko/shotgun/compare/0.6...0.7
- Static files now served from the shotgun master process, making shotgun tolerable for apps with many/unbundled static assets.
- Added --public (-P) for specifying a non-standard root / public directory.
- Response bodies are now streamed over the master < worker pipe instead of being marshalled. Improves performance with large response bodies, and reduces shotgun master process RES usage.
- GET /favicon.ico requests are served an empty response by the shotgun master process. Prevents the need to fork a worker process.
- INT, TERM, QUIT now properly trigger server shutdown. The second INT, TERM, QUIT causes the master process to exit hard.
- Non .ru config files (e.g., sinatra app files) may now define command line options in the same way as .ru files: by including a #\ -p 5555 ... line.