Class: Falcon::Proxy

Inherits:
Async::HTTP::Middleware
  • Object
show all
Defined in:
lib/falcon/proxy.rb

Constant Summary collapse

FORWARDED = 
'forwarded'.freeze
X_FORWARDED_FOR = 
'x-forwarded-for'.freeze
X_FORWARDED_PROTO = 
'x-forwarded-proto'.freeze
VIA = 
'via'.freeze
CONNECTION = 
::HTTP::Protocol::CONNECTION
HOP_HEADERS = 
[
  'connection',
  'keep-alive',
  'public',
  'proxy-authenticate',
  'transfer-encoding',
  'upgrade',
]

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(app, hosts) ⇒ Proxy 



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# File 'lib/falcon/proxy.rb', line 51

def initialize(app, hosts)
  super(app)
  
  @server_context = nil
  
  @hosts = hosts
  @clients = {}
  
  @count = 0
end

Instance Attribute Details

#count ⇒ Object (readonly)

Returns the value of attribute count.



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# File 'lib/falcon/proxy.rb', line 62

def count
  @count
end

Instance Method Details

#call(request) ⇒ Object 



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# File 'lib/falcon/proxy.rb', line 122

def call(request)
  if host = lookup(request)
    @count += 1
    
    request = self.prepare_request(request, host)
    
    client = connect(host.endpoint)
    
    client.call(request)
  else
    super
  end
rescue
  Async.logger.error(self) {$!}
  return Async::HTTP::Response[502, {'content-type' => 'text/plain'}, ["#{$!.inspect}: #{$!.backtrace.join("\n")}"]]
end

#close ⇒ Object 



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# File 'lib/falcon/proxy.rb', line 64

def close
  @clients.each_value(&:close)
  
  super
end

#connect(endpoint) ⇒ Object 



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# File 'lib/falcon/proxy.rb', line 70

def connect(endpoint)
  @clients[endpoint] ||= Async::HTTP::Client.new(endpoint)
end

#lookup(request) ⇒ Object 



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# File 'lib/falcon/proxy.rb', line 74

def lookup(request)
  # Trailing dot and port is ignored/normalized.
  if authority = request.authority.sub(/(\.)?(:\d+)?$/, '')
    return @hosts[authority]
  end
end

#prepare_headers(headers) ⇒ Object 



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# File 'lib/falcon/proxy.rb', line 81

def prepare_headers(headers)
  if connection = headers[CONNECTION]
    headers.slice!(connection)
  end
  
  headers.slice!(HOP_HEADERS)
end

#prepare_request(request, host) ⇒ Object 



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# File 'lib/falcon/proxy.rb', line 89

def prepare_request(request, host)
  forwarded = []
  
  # Async.logger.info(self) do |buffer|
  #  buffer.puts "Request authority: #{request.authority}"
  #  buffer.puts "Host authority: #{host.authority}"
  #  buffer.puts "Endpoint authority: #{host.endpoint.authority}"
  # end
  
  # The authority of the request must match the authority of the endpoint we are proxying to, otherwise SNI and other things won't work correctly.
  request.authority = host.endpoint.authority
  
  if address = request.remote_address
    request.headers.add(X_FORWARDED_FOR, address.ip_address)
    forwarded << "for=#{address.ip_address}"
  end
  
  if scheme = request.scheme
    request.headers.add(X_FORWARDED_PROTO, scheme)
    forwarded << "proto=#{scheme}"
  end
  
  unless forwarded.empty?
    request.headers.add(FORWARDED, forwarded.join(';'))
  end
  
  request.headers.add(VIA, "#{request.version} #{self.class}")
  
  self.prepare_headers(request.headers)
  
  return request
end