Module: MiddleSquid::Helpers

Included in:
Runner
Defined in:
lib/middle_squid/helpers.rb

Predefined Helpers collapse

Instance Method Details

#download_like(request, uri) ⇒ Array

Note:

This method must be called inside an active fiber. Actions#intercept does it automatically.

Download a resource with the same headers and body as a rack request.

Examples:

Transparent Proxying

run lambda {|uri, extras|
  # you should use 'accept' instead of doing this
  intercept {|req, res|
    download_like req, uri
  }
}

Body Modification

run lambda {|uri, extras|
  intercept {|req, res|
    status, headers, body = download_like req, uri

    content_type = headers['Content-Type'].to_s

    if content_type.include? 'text/html'
      body.gsub! 'green', 'blue'
    end

    [status, headers, body]
  }
}

Parameters:

  • request (Rack::Request) —

    the request to imitate

  • uri (#to_s) —

    the resource to fetch

Returns:

  • (Array) —

    a rack triplet (status code, response headers and body)

See Also:



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# File 'lib/middle_squid/helpers.rb', line 35

def download_like(request, uri)
  fiber = Fiber.current

  method = request.request_method.downcase.to_sym

  headers = {'Content-Type' => request.env['CONTENT_TYPE']}
  request.env.
    select {|k| k.start_with? 'HTTP_' }.
    each {|key, val| headers[key[5..-1]] = val }

  headers.sanitize_headers!

  options = {
    :head => headers,
    :body => request.body.read,
  }

  http = EM::HttpRequest.new(uri.to_s).send method, options

  http.callback {
    status = http.response_header.status
    headers = http.response_header
    body = http.response

    headers.sanitize_headers!

    fiber.resume [status, headers, body]
  }

  http.errback {
    fiber.resume [
      520,
      {'Content-Type' => 'text/plain'},
      "[MiddleSquid] #{http.error}"
    ]
  }

  Fiber.yield
end