Class: FDK::Listener

Inherits:
Object
  • Object
show all
Defined in:
lib/fdk/listener.rb

Overview

Represents the socket that Fn uses to communicate with the FDK (and thence the function) To avoid Fn trying to connect to the socket before it’s ready, the Listener creates a socket on (private_socket_path).

When the socket is ready to accept connections, the FDK links the private_socket_path to the socket_path.

Fn waits for the socket_path to be created and then connects

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(url:) ⇒ Listener

Returns a new instance of Listener.



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# File 'lib/fdk/listener.rb', line 14

def initialize(url:)
  if url.nil? || !url.start_with?("unix:/")
    raise "Missing or invalid socket URL in FN_LISTENER."
  end

  @url = url
  @private_socket = UNIXServer.open(private_socket_path)
end

Instance Attribute Details

#private_socket ⇒ Object (readonly)

Returns the value of attribute private_socket.



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# File 'lib/fdk/listener.rb', line 12

def private_socket
  @private_socket
end

#url ⇒ Object (readonly)

Returns the value of attribute url.



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# File 'lib/fdk/listener.rb', line 12

def url
  @url
end

Instance Method Details

#handle_request(fn_block:) ⇒ Object 



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# File 'lib/fdk/listener.rb', line 47

def handle_request(fn_block:)
  local_socket = socket.accept
  req = WEBrick::HTTPRequest.new(WEBrick::Config::HTTP)
  resp = WEBrick::HTTPResponse.new(WEBrick::Config::HTTP)
  req.parse(local_socket)
  FDK.debug "got request #{req}"
  fn_block.call(req, resp)
  resp.send_response(local_socket)
  FDK.debug "sending resp  #{resp.status}, #{resp.header}"
  local_socket.close
end

#link_socket_file ⇒ Object 



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# File 'lib/fdk/listener.rb', line 28

def link_socket_file
  File.chmod(0o666, private_socket_path)
  FileUtils.ln_s(File.basename(private_socket_path), socket_path)
  FDK.debug "listening on #{private_socket_path}->#{socket_path}"
end

#listen(&block) ⇒ Object 



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# File 'lib/fdk/listener.rb', line 34

def listen(&block)
  raise StandardError("No block given") unless block_given?

  begin
    loop do
      handle_request(fn_block: block)
    end
  rescue StandardError => e
    FDK.log(entry: "Error in request handling #{e}")
    FDK.log(entry: e.backtrace)
  end
end

#private_socket_path ⇒ Object 



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# File 'lib/fdk/listener.rb', line 63

def private_socket_path
  socket_path + ".private"
end

#socket ⇒ Object 



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# File 'lib/fdk/listener.rb', line 23

def socket
  link_socket_file unless @socket
  @socket ||= private_socket
end

#socket_path ⇒ Object 



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# File 'lib/fdk/listener.rb', line 59

def socket_path
  @socket_path ||= url[5..url.length]
end