Stupid Rack
Middleware
Tricks
josh@aiderss.com
@joshbuddy
http://github.com/joshbuddy

What is Rack?

What is Rack?
Standard interface for HTTP servers and application.

What is Rack?
Standard interface for HTTP servers and application.
CGI, FastCGI,
Mongrel, Thin,
WEBrick
and many more!

What is Rack?
Standard interface for HTTP servers and application.
CGI, FastCGI, Rails, Merb,
Mongrel, Thin, Sinatra, Ramaze,
WEBrick a proc
and many more! your next great
framework

What is Rack
Middleware?

What is Rack
Middleware?
HTTP Server

What is Rack
Middleware?
HTTP Server Application

What is Rack
Middleware?
HTTP Server Application

What is Rack
Middleware?
Transparent
Intercepting
Caching
Content filtering

What is Rack
Middleware?
Transparent
Intercepting
Caching
Content filtering
(insert your thingy here)

My Challenge

My Challenge
I'm going to write a
new Rack
Middleware
everyday of
RailsConf.

My Challenge
I'm going to write a
new Rack
Middleware
everyday of
RailsConf.
(with tests)

#1 Rack::Rewrite
http://github.com/joshbuddy/rack-rewrite

#1 Rack::Rewrite
http://github.com/joshbuddy/rack-rewrite
Get a request, rewrite it!

#1 Rack::Rewrite
http://github.com/joshbuddy/rack-rewrite
Get a request, rewrite it!
I hates this

#1 Rack::Rewrite
http://github.com/joshbuddy/rack-rewrite
use Rack::Rewrite do
on :method => 'get' do
# If the request has a has a param of kitten=cute or
# kitten=happy, lets log it and pass it on!
#
on :params => {:kitten => /cute|happy/} do
act { log('what a nice cat') }
pass
end
fail
end
end

#2 Rack::Regenerate
http://github.com/joshbuddy/rack-regenerate

#2 Rack::Regenerate
http://github.com/joshbuddy/rack-regenerate
No idea.
But say you had a request. And it was something you
wanted to get hit every five minutes.

#2 Rack::Regenerate
http://github.com/joshbuddy/rack-regenerate
X-Cache-Regenerate: [interval in seconds] [number of times to call]

#2 Rack::Regenerate
http://github.com/joshbuddy/rack-regenerate
X-Cache-Regenerate: [interval in seconds] [number of times to call]
X-Cache-Regenerate: 2 5
Request

#2 Rack::Regenerate
http://github.com/joshbuddy/rack-regenerate
X-Cache-Regenerate: [interval in seconds] [number of times to call]
X-Cache-Regenerate: 2 5
Request Response

#2 Rack::Regenerate
http://github.com/joshbuddy/rack-regenerate
X-Cache-Regenerate: [interval in seconds] [number of times to call]
X-Cache-Regenerate: 2 5
Request Response
Intercept

#2 Rack::Regenerate
http://github.com/joshbuddy/rack-regenerate
X-Cache-Regenerate: [interval in seconds] [number of times to call]
X-Cache-Regenerate: 2 5
Request Response
Intercept
2 seconds

#2 Rack::Regenerate
http://github.com/joshbuddy/rack-regenerate
X-Cache-Regenerate: [interval in seconds] [number of times to call]
X-Cache-Regenerate: 2 5
Request Response
Intercept
2 seconds
2 seconds

#2 Rack::Regenerate
http://github.com/joshbuddy/rack-regenerate
X-Cache-Regenerate: [interval in seconds] [number of times to call]
X-Cache-Regenerate: 2 5
Request Response
Intercept
2 seconds
2 seconds
5.times!

#3 Rack::Capabilities
http://github.com/joshbuddy/rack-capabilities

#3 Rack::Capabilities
http://github.com/joshbuddy/rack-capabilities
Middleware

#3 Rack::Capabilities
http://github.com/joshbuddy/rack-capabilities
Middleware
Middleware

#3 Rack::Capabilities
http://github.com/joshbuddy/rack-capabilities
Middleware
Middleware
Middleware

#3 Rack::Capabilities
http://github.com/joshbuddy/rack-capabilities
Middleware
Middleware
Middleware
Middleware

#3 Rack::Capabilities
http://github.com/joshbuddy/rack-capabilities
Middleware
Who’s that
Middleware
middleware
Middleware
?
Middleware

#3 Rack::Capabilities
http://github.com/joshbuddy/rack-capabilities
# who is before me?
Rack::Capabilities.before(self)
# who is after me?
Rack::Capabilities.after(self)
# where can I go find AGoodTime?
Rack::Capabilities.find(AGoodTime)
# ==> nil

#4 Rack::CacheWhileRevalidate
http://github.com/joshbuddy/rack-cache-while-revalidate

#4 Rack::CacheWhileRevalidate
http://github.com/joshbuddy/rack-cache-while-revalidate
Request

#4 Rack::CacheWhileRevalidate
http://github.com/joshbuddy/rack-cache-while-revalidate
Request Cache

#4 Rack::CacheWhileRevalidate
http://github.com/joshbuddy/rack-cache-while-revalidate
STALE!
Request Cache

#4 Rack::CacheWhileRevalidate
http://github.com/joshbuddy/rack-cache-while-revalidate
Request Cache Application
Revalidate
Serve stale data

The End?