EM-Proxy
EventMachine Proxy DSL for writing high-performance transparent / intercepting proxies in Ruby.
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Slides from RailsConf 2009: bit.ly/D7oWB
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GoGaRuCo notes & Slides: www.igvita.com/2009/04/20/ruby-proxies-for-scale-and-monitoring/
Getting started
# install & configure gemcutter repos
gem update --system
gem install gemcutter
gem tumble
gem install em-proxy
irb:0> require 'em-proxy'
Simple port forwarding proxy
Proxy.start(:host => "0.0.0.0", :port => 80, :debug => true) do |conn|
conn.server :srv, :host => "127.0.0.1", :port => 81
# modify / process request stream
conn.on_data do |data|
p [:on_data, data]
data
end
# modify / process response stream
conn.on_response do |backend, resp|
p [:on_response, backend, resp]
resp
end
# termination logic
conn.on_finish do |backend|
p [:on_finish, name]
# terminate connection (in duplex mode, you can terminate when prod is done)
unbind if backend == :srv
end
end
For more examples see the /examples directory.
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SMTP Spam Filtering
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Duplicating traffic
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Selective forwarding
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Beanstalkd interceptor
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etc.