Class: Apigatewayv2Rack::Middlewares::CloudfrontXff

Inherits:
Object
  • Object
show all
Defined in:
lib/apigatewayv2_rack/middlewares/cloudfront_xff.rb

Overview

Apigatewayv2Rack::Middlewares::CloudfrontXff transforms cloudfront-viewer-address to x-forwarded-for value. It is recommended to use with Apigatewayv2Rack::Middlewares::CloudfrontVerify.

Constant Summary collapse

V6_REGEXP = 
/^([a-f0-9:]+):(\d+)$/

Instance Method Summary collapse

Constructor Details

#initialize(app, replace_remote_addr_with: '127.0.0.1') ⇒ CloudfrontXff

When replace_remote_addr_with is set, REMOTE_ADDR will be replaced with given value; this allows Rack::Request#ip to respect xff on its default ip_filter. Default to 127.0.0.1.



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# File 'lib/apigatewayv2_rack/middlewares/cloudfront_xff.rb', line 10

def initialize(app, replace_remote_addr_with: '127.0.0.1')
  @app = app
  @replace_remote_addr_with = replace_remote_addr_with
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/apigatewayv2_rack/middlewares/cloudfront_xff.rb', line 17

def call(env)
  viewer = env['HTTP_CLOUDFRONT_VIEWER_ADDRESS']
  if viewer
    addr,port = if viewer.include?('.')
      viewer.split(?:, 2)
    else
      viewer.downcase.match(V6_REGEXP)&.to_a[1,2]
    end

    if addr && port
      env['HTTP_X_APIGATEWAYV2RACK_ORIG_X_FORWARDED_FOR'] = env['HTTP_X_FORWARDED_FOR'] if env['HTTP_X_FORWARDED_FOR']
      env['HTTP_X_APIGATEWAYV2RACK_ORIG_X_FORWARDED_PORT'] = env['HTTP_X_FORWARDED_PORT'] if env['HTTP_X_FORWARDED_PORT']
      env['HTTP_X_FORWARDED_FOR'] = addr
      env['HTTP_X_FORWARDED_PORT'] = port

      if @replace_remote_addr_with
        env['HTTP_X_APIGATEWAYV2RACK_ORIG_REMOTE_ADDR'] = env['REMOTE_ADDR'] if env['REMOTE_ADDR']
        env['REMOTE_ADDR'] = @replace_remote_addr_with
      end
    end
  end

  @app.call(env)
end