Contributed Rack Middleware and Utilities
This package includes a variety of add-on components for Rack, a Ruby web server interface:
Rack::Access- Limits access based on IP address
Rack::Backstage- Returns content of specified file if it exists, which makes it convenient for putting up maintenance pages.
Rack::BounceFavicon- Returns a 404 for requests to
Rack::CSSHTTPRequest- Adds CSSHTTPRequest support by encoding responses as CSS for cross-site AJAX-style data loading
Rack::Callbacks- Implements DSL for pure before/after filter like Middlewares.
Rack::Config- Shared configuration for cooperative middleware.
Rack::Cookies- Adds simple cookie jar hash to env
Rack::Deflect- Helps protect against DoS attacks.
Rack::Evil- Lets the rack application return a response to the client from any place.
/host-metausing a block
Rack::JSONP- Adds JSON-P support by stripping out the callback param and padding the response with the appropriate callback format.
Rack::LazyConditionalGet- Caches a global
Last-Modifieddate and updates it each time there is a request that is not
Rack::LighttpdScriptNameFix- Fixes how lighttpd sets the
PATH_INFOvariables in certain configurations.
Rack::Locale- Detects the client locale using the Accept-Language request header and sets a
rack.localevariable in the environment.
Rack::MailExceptions- Rescues exceptions raised from the app and sends a useful email with the exception, stacktrace, and contents of the environment.
Rack::NestedParams- parses form params with subscripts (e.g., * "
post[title]=Hello") into a nested/recursive Hash structure (based on Rails' implementation).
Rack::NotFound- A default 404 application.
Rack::PostBodyContentTypeParser- Adds support for JSON request bodies. The Rack parameter hash is populated by deserializing the JSON data provided in the request body when the Content-Type is application/json.
Rack::Printout- Prints the environment and the response per request
Rack::ProcTitle- Displays request information in process title (
$0) for monitoring/inspection with ps(1).
Rack::Profiler- Uses ruby-prof to measure request time.
Rack::RelativeRedirect- Transforms relative paths in redirects to absolute URLs.
Rack::ResponseCache- Caches responses to requests without query strings to Disk or a user provided Ruby object. Similar to Rails' page caching.
Rack::ResponseHeaders- Manipulates response headers object at runtime
Rack::Signals- Installs signal handlers that are safely processed after a request
Rack::SimpleEndpoint- Creates simple endpoints with routing rules, similar to Sinatra actions
Rack::StaticCache- Modifies the response headers to facilitiate client and proxy caching for static files that minimizes http requests and improves overall load times for second time visitors.
Rack::TryStatic- Tries to match request to a static file
Git is the quickest way to the rack-contrib sources:
git clone git://github.com/rack/rack-contrib.git
Gems are available too:
gem install rack-contrib
'rack/contrib' will add autoloads to the Rack modules for all of the
components included. The following example shows what a simple rackup
config.ru) file might look like:
require 'rack' require 'rack/contrib' use :: if ENV['RACK_ENV'] == 'development' use ::ETag use :: run theapp
This package is semver compliant; you should use a
pessimistic version constraint (
~>) against the relevant
2.x version of
This version of
rack-contrib is only compatible with
rack 2.x. If you
rack 1.x, you will need to use
rack-contrib 1.x. A suitable
pessimistic version constraint (
~>) is recommended.
To contribute to the project, begin by cloning the repo and installing the necessary gems:
gem install json rack ruby-prof test-spec test-unit
To run the entire test suite, run
To run a specific component's tests run
specrb -Ilib:test -w test/spec_rack_thecomponent.rb
This works on ruby 1.8.7 but has problems under ruby 1.9.x.
TODO: instructions for 1.9.x and include bundler
Criteria for inclusion
The criteria for middleware being included in this project are roughly as follows:
- For patterns that are very common, provide a reference implementation so that other projects do not have to reinvent the wheel.
- For patterns that are very useful or interesting, provide a well-done implementation.
- The middleware fits in 1 code file and is relatively small. Currently all middleware in the project are < 150 LOC.
- The middleware doesn't have any dependencies other than rack and the ruby standard library.
These criteria were introduced several years after the start of the project, so some of the included middleware may not meet all of them. In particular, several middleware have external dependencies. It is possible that in some future release of rack-contrib, middleware with external depencies will be removed from the project.
When submitting code keep the above criteria in mind and also see the code guidelines in CONTRIBUTING.md.