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by Christian Neukirchen.
Original Post: Rack 0.2, a modular Ruby webserver interface
Feed Title: chris blogs: Ruby stuff
Feed URL: http://chneukirchen.org/blog/category/ruby.atom
Feed Description: a weblog by christian neukirchen - Ruby stuff
Rack provides a minimal, modular and adaptable interface for developing
web applications in Ruby. By wrapping HTTP requests and responses in
the simplest way possible, it unifies and distills the API for web
servers, web frameworks, and software in between (the so-called
middleware) into a single method call.
The exact details of this are described in the Rack specification,
which all Rack applications should conform to.
Supported web servers
The included handlers connect all kinds of web servers to Rack:
Mongrel
Mongrel/Swiftcore (require it before Rack.)
WEBrick
FCGI
CGI
Any valid Rack app will run the same on all these handlers, without
changing anything.
Supported web frameworks
The included adapters connect Rack with existing Ruby web frameworks:
Camping
These frameworks include Rack adapters in their distributions:
Ramaze
Maveric
Racktools::SimpleApplication
Available middleware
Between the server and the framework, Rack can be customized to your
applications needs using middleware, for example:
Rack::URLMap, to route to multiple applications inside the same process.
Rack::CommonLogger, for creating Apache-style logfiles.
Rack::ShowException, for catching unhandled exceptions and
presenting them in a nice and helpful way with clickable backtrace.
Rack::File, for serving static files.
…
All these components use the same interface, which is described in
detail in the Rack specification. You can choose to use them exactly
in the way you want.
Convenience
If you want to develop outside of existing frameworks, implement your
own ones, or develop middleware, Rack provides many helpers to create
Rack applications quickly and without doing the same web stuff all
over:
Rack::Request, which also provides query string parsing and
multipart handling.
Rack::Response, for convenient generation of HTTP replies and
cookie handling.
Rack::MockRequest and Rack::MockResponse for efficient and quick
testing of Rack application without real HTTP round-trips.
rackup
rackup is a useful tool for running Rack applications, which uses the
Rack::Builder DSL to configure middleware and build up applications
easily.
rackup automatically figures out the environment it is run in, and
runs your application as FastCGI, CGI, or standalone with Mongrel or
WEBrick—all from the same configuration.