Class: ThreadedProxy::Client

Inherits:
Object
  • Object
show all
Defined in:
lib/threaded_proxy/client.rb

Constant Summary collapse

DISALLOWED_RESPONSE_HEADERS = 
%w[keep-alive].freeze
HTTP_METHODS = 
{
  'get' => Net::HTTP::Get,
  'post' => Net::HTTP::Post,
  'put' => Net::HTTP::Put,
  'delete' => Net::HTTP::Delete,
  'head' => Net::HTTP::Head,
  'options' => Net::HTTP::Options,
  'trace' => Net::HTTP::Trace
}.freeze
CALLBACK_METHODS = 
%i[
  on_response
  on_headers
  on_complete
  on_error
].freeze
DEFAULT_OPTIONS = 
{
  headers: {},
  debug: false,
  method: :get
}.freeze

Instance Method Summary collapse

Constructor Details

#initialize(origin_url, options = {}) {|_self| ... } ⇒ Client

Returns a new instance of Client.

Yields:

  • (_self)

Yield Parameters:



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# File 'lib/threaded_proxy/client.rb', line 46

def initialize(origin_url, options = {})
  @origin_url = Addressable::URI.parse(origin_url)
  @options = DEFAULT_OPTIONS.merge(options)
  @wrote_headers = false

  @callbacks = {}
  (CALLBACK_METHODS - [:on_error]).each do |method_name|
    @callbacks[method_name] = proc {}
  end
  @callbacks[:on_error] = proc { |e| raise e }

  yield(self) if block_given?
end

Instance Method Details

#default_port(uri) ⇒ Object 



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# File 'lib/threaded_proxy/client.rb', line 135

def default_port(uri)
  case uri.scheme
  when 'http'
    80
  when 'https'
    443
  end
end

#log(message) ⇒ Object 



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# File 'lib/threaded_proxy/client.rb', line 60

def log(message)
  warn message if @options[:debug]
end

#start(socket) ⇒ Object 



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# File 'lib/threaded_proxy/client.rb', line 64

def start(socket)
  request_method = @options[:method].to_s.downcase
  request_headers = @options[:headers].merge('Connection' => 'close')

  request_class = HTTP_METHODS[request_method]
  http_request = request_class.new(@origin_url, request_headers)
  if @options[:body].respond_to?(:read)
    http_request.body_stream = @options[:body]
  elsif @options[:body].is_a?(String)
    http_request.body = @options[:body]
  end

  socket_responder = SocketResponder.new(socket)

  ActiveSupport::Notifications.instrument('threaded_proxy.fetch', method: request_method, url: @origin_url.to_s,
                                                                  headers: request_headers) do
    http = HTTP.new(@origin_url.host, @origin_url.port || default_port(@origin_url))
    http.use_ssl = (@origin_url.scheme == 'https')
    http.set_debug_output($stderr) if @options[:debug]
    http.verify_mode = OpenSSL::SSL::VERIFY_NONE if @options[:ignore_ssl_errors]

    http.start do
      http.request(http_request) do |client_response|
        @callbacks[:on_response].call(client_response, socket_responder)
        break if socket.closed?

        log('Writing response status and headers')
        write_headers(client_response, socket)
        break if socket.closed?

        raise ResponseBodyAlreadyConsumedError if client_response.read?

        # There may have been some existing data in client_response's read buffer, flush it out
        # before we manually connect the raw sockets
        log('Flushing existing response buffer to client')
        http.flush_existing_buffer_to(socket)

        # Copy the rest of the client response to the socket
        log('Copying response body to client')
        http.copy_to(socket)

        @callbacks[:on_complete].call(client_response)
      end
    end
  rescue StandardError => e
    @callbacks[:on_error].call(e, socket_responder)
    # Default to 500 if the error callback didn't write a response
    socket_responder.render(status: 500, text: 'Internal Server Error') unless socket.closed? || @wrote_headers

    socket.close unless socket.closed?
  end
end

#write_headers(client_response, socket) ⇒ Object 



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# File 'lib/threaded_proxy/client.rb', line 117

def write_headers(client_response, socket)
  socket.write "HTTP/1.1 #{client_response.code} #{client_response.message}\r\n"

  # We don't support reusing connections once we have disconnected them from rack
  client_response['connection'] = 'close'

  @callbacks[:on_headers].call(client_response, socket)
  return if socket.closed?

  client_response.each_header do |key, value|
    socket.write "#{key}: #{value}\r\n" unless DISALLOWED_RESPONSE_HEADERS.include?(key.downcase)
  end

  # Done with headers
  socket.write "\r\n"
  @wrote_headers = true
end