Class: DeployAgent::ServerConnection

Inherits:
Object
  • Object
show all
Defined in:
lib/deploy_agent/server_connection.rb

Overview

The ServerConnection class deals with all communication with the Deploy server

Defined Under Namespace

Classes: ServerDisconnected

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(agent, server_host, nio_selector, check_certificate = true) ⇒ ServerConnection

Create a secure TLS connection to the Deploy server



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# File 'lib/deploy_agent/server_connection.rb', line 13

def initialize(agent, server_host, nio_selector, check_certificate=true)
  @agent = agent
  @agent.logger.info "Attempting to connect to #{server_host}"
  @destination_connections = {}
  @nio_selector = nio_selector

  # Create a TCP socket to the Deploy server
  @tcp_socket = TCPSocket.new(server_host, 7777)

  # Configure an OpenSSL context with server vertification
  ctx = OpenSSL::SSL::SSLContext.new
  ctx.verify_mode = check_certificate ? OpenSSL::SSL::VERIFY_PEER : OpenSSL::SSL::VERIFY_NONE
  # Load the agent certificate and key used to authenticate this agent
  ctx.cert = OpenSSL::X509::Certificate.new(File.read(CERTIFICATE_PATH))
  ctx.key = OpenSSL::PKey::RSA.new(File.read(KEY_PATH))
  # Load the Deploy CA used to verify the server
  ctx.ca_file = CA_PATH

  # Create the secure connection
  @socket = OpenSSL::SSL::SSLSocket.new(@tcp_socket, ctx)
  @socket.connect
  # Check the remote certificate
  @socket.post_connection_check(server_host) if check_certificate
  # Create send and receive buffers
  @tx_buffer = String.new.force_encoding('BINARY')
  @rx_buffer = String.new.force_encoding('BINARY')

  @nio_monitor = @nio_selector.register(@tcp_socket, :r)
  @nio_monitor.value = self

  @agent.logger.info "Successfully connected to server"
rescue => e
  @agent.logger.info "Something went wrong connecting to server."
  # Sleep between 10 and 20 seconds
  random_sleep = rand(10) + 10
  @agent.logger.info "#{e.to_s} #{e.message}"
  @agent.logger.info "Retrying in #{random_sleep} seconds."
  sleep random_sleep
  retry
end

Instance Attribute Details

#agent ⇒ Object (readonly)

Returns the value of attribute agent.



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# File 'lib/deploy_agent/server_connection.rb', line 9

def agent
  @agent
end

#destination_connections ⇒ Object (readonly)

Returns the value of attribute destination_connections.



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# File 'lib/deploy_agent/server_connection.rb', line 9

def destination_connections
  @destination_connections
end

#nio_monitor=(value) ⇒ Object (writeonly)

Sets the attribute nio_monitor

Parameters:

  • value —

    the value to set the attribute nio_monitor to.



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# File 'lib/deploy_agent/server_connection.rb', line 10

def nio_monitor=(value)
  @nio_monitor = value
end

Instance Method Details

#destination_allowed?(destination) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/deploy_agent/server_connection.rb', line 113

def destination_allowed?(destination)
  return false unless File.file?(ACCESS_PATH)
  DeployAgent.allowed_destinations.each do |network|
    begin
      return true if IPAddr.new(network).include?(destination)
    rescue IPAddr::InvalidAddressError
      # Not a valid IP or netmask, deny and continue
    end
  end
  false
end

#rx_data ⇒ Object

Receive and process packets from the control server



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# File 'lib/deploy_agent/server_connection.rb', line 55

def rx_data
  # Ensure all received data is read
  @rx_buffer << @socket.readpartial(10240)
  while(@socket.pending > 0)
    @rx_buffer << @socket.readpartial(10240)
  end
  # Wait until we have a complete packet of data
  while @rx_buffer.bytesize >=2 && @rx_buffer.bytesize >= @rx_buffer[0,2].unpack('n')[0]
    length = @rx_buffer.slice!(0,2).unpack('n')[0]
    # Extract the packet from the buffered stream
    packet = @rx_buffer.slice!(0,length-2)
    # Check what type of packet we have received
    case packet.bytes[0]
    when 1
      # Process new connection request
      id = packet[1,2].unpack('n')[0]
      host, port = packet[3..-1].split('/', 2)
      @agent.logger.info "[#{id}] Connection request from server: #{host}:#{port}"
      return send_connection_error(id, "Destination address not allowed") unless destination_allowed?(host)

      begin
        # Create conenction to the final destination and save info by id
        @destination_connections[id] = DestinationConnection.new(host, port, id, @nio_selector, self)
      rescue => e
        # Something went wrong, inform the Deploy server
        @agent.logger.error "An error occurred: #{e.message}"
        @agent.logger.error e.backtrace
        send_connection_error(id, e.message)
      end
    when 3
      # Process a connection close request
      id = packet[1,2].unpack('n')[0]
      if @destination_connections[id]
        @agent.logger.info "[#{id}] Close requested by server, closing"
        @destination_connections[id].close
      else
        @agent.logger.info "[#{id}] Close requested by server, not open"
      end
    when 4
      # Data incoming, send it to the backend
      id = packet[1,2].unpack('n')[0]
      @agent.logger.debug "[#{id}] #{packet.bytesize} bytes received from server"
      @destination_connections[id].send_data(packet[3..-1])
    when 5
      # This is a shutdown request. Disconnect and don't re-attempt connection.
      @agent.logger.warn "Server rejected connection. Shutting down."
      @agent.logger.warn packet[1..-1]
      Process.exit(0)
    when 6
      # This is a shutdown request. Disconnect and don't re-attempt connection.
      @agent.logger.warn "Server requested reconnect. Closing connection."
      close
    end
  end
rescue EOFError, Errno::ECONNRESET
  close
end

#send_connection_close(id) ⇒ Object

Notify server of closed connection



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# File 'lib/deploy_agent/server_connection.rb', line 136

def send_connection_close(id)
  send_packet([3, id].pack('Cn'))
end

#send_connection_error(id, reason) ⇒ Object

Notify server of failed connection



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# File 'lib/deploy_agent/server_connection.rb', line 131

def send_connection_error(id, reason)
  send_packet([2, id, 1, reason].pack('CnCa*'))
end

#send_connection_success(id) ⇒ Object

Notify server of successful connection



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# File 'lib/deploy_agent/server_connection.rb', line 126

def send_connection_success(id)
  send_packet([2, id, 0].pack('CnC'))
end

#send_data(id, data) ⇒ Object

Proxy data (coming from the backend) to the Deploy server



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# File 'lib/deploy_agent/server_connection.rb', line 141

def send_data(id, data)
  send_packet([4, id, data].pack('Cna*'))
end

#tx_data ⇒ Object

Called by event loop to send all waiting packets to the Deploy server



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# File 'lib/deploy_agent/server_connection.rb', line 146

def tx_data
  bytes_sent = @socket.write_nonblock(@tx_buffer[0,1024])
  # Send as much data as possible
  if bytes_sent >= @tx_buffer.bytesize
    @tx_buffer = String.new.force_encoding('BINARY')
    @nio_monitor.interests = :r
  else
    # If we didn't manage to send all the data, leave
    # the remaining data in the send buffer
    @tx_buffer.slice!(0, bytes_sent)
  end
rescue EOFError, Errno::ECONNRESET
  close
end