Class: Fluent::Plugin::ForwardOutput::Node

Inherits:
Object
  • Object
show all
Defined in:
lib/fluent/plugin/out_forward.rb

Direct Known Subclasses

NoneHeartbeatNode

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(sender, server, failure:) ⇒ Node

Returns a new instance of Node.



505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
 
# File 'lib/fluent/plugin/out_forward.rb', line 505

def initialize(sender, server, failure:)
  @sender = sender
  @log = sender.log
  @compress = sender.compress

  @name = server.name
  @host = server.host
  @port = server.port
  @weight = server.weight
  @standby = server.standby
  @failure = failure
  @available = true
  @state = nil

  # @hostname is used for certificate verification & TLS SNI
  host_is_hostname = !(IPAddr.new(@host) rescue false)
  @hostname = case
              when host_is_hostname then @host
              when @name then @name
              else nil
              end

  @usock = nil

  @username = server.username
  @password = server.password
  @shared_key = server.shared_key || (sender.security && sender.security.shared_key) || ""
  @shared_key_salt = generate_salt
  @shared_key_nonce = ""

  @unpacker = Fluent::Engine.msgpack_unpacker

  @resolved_host = nil
  @resolved_time = 0
  @resolved_once = false
end

Instance Attribute Details

#available ⇒ Object (readonly)

for test



546
547
548
 
# File 'lib/fluent/plugin/out_forward.rb', line 546

def available
  @available
end

#failure ⇒ Object (readonly)

for test



546
547
548
 
# File 'lib/fluent/plugin/out_forward.rb', line 546

def failure
  @failure
end

#host ⇒ Object (readonly)

Returns the value of attribute host.



544
545
546
 
# File 'lib/fluent/plugin/out_forward.rb', line 544

def host
  @host
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



544
545
546
 
# File 'lib/fluent/plugin/out_forward.rb', line 544

def name
  @name
end

#port ⇒ Object (readonly)

Returns the value of attribute port.



544
545
546
 
# File 'lib/fluent/plugin/out_forward.rb', line 544

def port
  @port
end

#sockaddr ⇒ Object (readonly)

used by on_heartbeat



545
546
547
 
# File 'lib/fluent/plugin/out_forward.rb', line 545

def sockaddr
  @sockaddr
end

#standby ⇒ Object (readonly)

Returns the value of attribute standby.



544
545
546
 
# File 'lib/fluent/plugin/out_forward.rb', line 544

def standby
  @standby
end

#state ⇒ Object (readonly)

Returns the value of attribute state.



544
545
546
 
# File 'lib/fluent/plugin/out_forward.rb', line 544

def state
  @state
end

#usock ⇒ Object

Returns the value of attribute usock.



542
543
544
 
# File 'lib/fluent/plugin/out_forward.rb', line 542

def usock
  @usock
end

#weight ⇒ Object (readonly)

Returns the value of attribute weight.



544
545
546
 
# File 'lib/fluent/plugin/out_forward.rb', line 544

def weight
  @weight
end

Instance Method Details

#available? ⇒ Boolean

Returns:



552
553
554
 
# File 'lib/fluent/plugin/out_forward.rb', line 552

def available?
  @available
end

#check_helo(message) ⇒ Object 



750
751
752
753
754
755
756
757
758
759
760
761
 
# File 'lib/fluent/plugin/out_forward.rb', line 750

def check_helo(message)
  @log.debug "checking helo"
  # ['HELO', options(hash)]
  unless message.size == 2 && message[0] == 'HELO'
    return false
  end
  opts = message[1] || {}
  # make shared_key_check failed (instead of error) if protocol version mismatch exist
  @shared_key_nonce = opts['nonce'] || ''
  @authentication = opts['auth'] || ''
  true
end

#check_pong(message) ⇒ Object 



782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
 
# File 'lib/fluent/plugin/out_forward.rb', line 782

def check_pong(message)
  @log.debug "checking pong"
  # ['PONG', bool(authentication result), 'reason if authentication failed',
  #  self_hostname, sha512\_hex(salt + self_hostname + nonce + sharedkey)]
  unless message.size == 5 && message[0] == 'PONG'
    return false, 'invalid format for PONG message'
  end
  _pong, auth_result, reason, hostname, shared_key_hexdigest = message

  unless auth_result
    return false, 'authentication failed: ' + reason
  end

  if hostname == @sender.security.self_hostname
    return false, 'same hostname between input and output: invalid configuration'
  end

  clientside = Digest::SHA512.new.update(@shared_key_salt).update(hostname).update(@shared_key_nonce).update(@shared_key).hexdigest
  unless shared_key_hexdigest == clientside
    return false, 'shared key mismatch'
  end

  return true, nil
end

#disable! ⇒ Object 



556
557
558
 
# File 'lib/fluent/plugin/out_forward.rb', line 556

def disable!
  @available = false
end

#establish_connection(sock) ⇒ Object 



564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
 
# File 'lib/fluent/plugin/out_forward.rb', line 564

def establish_connection(sock)
  while available? && @state != :established
    begin
      # TODO: On Ruby 2.2 or earlier, read_nonblock doesn't work expectedly.
      # We need rewrite around here using new socket/server plugin helper.
      buf = sock.read_nonblock(@sender.read_length)
      if buf.empty?
        sleep @sender.read_interval
        next
      end
      @unpacker.feed_each(buf) do |data|
        on_read(sock, data)
      end
    rescue IO::WaitReadable
      # If the exception is Errno::EWOULDBLOCK or Errno::EAGAIN, it is extended by IO::WaitReadable.
      # So IO::WaitReadable can be used to rescue the exceptions for retrying read_nonblock.
      # http://docs.ruby-lang.org/en/2.3.0/IO.html#method-i-read_nonblock
      sleep @sender.read_interval unless @state == :established
    rescue SystemCallError => e
      @log.warn "disconnected by error", host: @host, port: @port, error: e
      disable!
      break
    rescue EOFError
      @log.warn "disconnected", host: @host, port: @port
      disable!
      break
    end
  end
end

#generate_ping ⇒ Object 



763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
 
# File 'lib/fluent/plugin/out_forward.rb', line 763

def generate_ping
  @log.debug "generating ping"
  # ['PING', self_hostname, sharedkey\_salt, sha512\_hex(sharedkey\_salt + self_hostname + nonce + shared_key),
  #  username || '', sha512\_hex(auth\_salt + username + password) || '']
  shared_key_hexdigest = Digest::SHA512.new.update(@shared_key_salt)
    .update(@sender.security.self_hostname)
    .update(@shared_key_nonce)
    .update(@shared_key)
    .hexdigest
  ping = ['PING', @sender.security.self_hostname, @shared_key_salt, shared_key_hexdigest]
  if !@authentication.empty?
    password_hexdigest = Digest::SHA512.new.update(@authentication).update(@username).update(@password).hexdigest
    ping.push(@username, password_hexdigest)
  else
    ping.push('','')
  end
  ping
end

#generate_salt ⇒ Object 



746
747
748
 
# File 'lib/fluent/plugin/out_forward.rb', line 746

def generate_salt
  SecureRandom.hex(16)
end

#heartbeat(detect = true) ⇒ Object 



734
735
736
737
738
739
740
741
742
743
744
 
# File 'lib/fluent/plugin/out_forward.rb', line 734

def heartbeat(detect=true)
  now = Time.now.to_f
  @failure.add(now)
  if detect && !@available && @failure.sample_size > @sender.recover_sample_size
    @available = true
    @log.warn "recovered forwarding server '#{@name}'", host: @host, port: @port
    true
  else
    nil
  end
end

#on_read(sock, data) ⇒ Object 



807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
 
# File 'lib/fluent/plugin/out_forward.rb', line 807

def on_read(sock, data)
  @log.trace __callee__

  case @state
  when :helo
    unless check_helo(data)
      @log.warn "received invalid helo message from #{@name}"
      disable! # shutdown
      return
    end
    sock.write(generate_ping.to_msgpack)
    @state = :pingpong
  when :pingpong
    succeeded, reason = check_pong(data)
    unless succeeded
      @log.warn "connection refused to #{@name}: #{reason}"
      disable! # shutdown
      return
    end
    @state = :established
    @log.debug "connection established", host: @host, port: @port
  else
    raise "BUG: unknown session state: #{@state}"
  end
end

#resolved_host ⇒ Object 



675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
 
# File 'lib/fluent/plugin/out_forward.rb', line 675

def resolved_host
  case @sender.expire_dns_cache
  when 0
    # cache is disabled
    resolve_dns!

  when nil
    # persistent cache
    @resolved_host ||= resolve_dns!

  else
    now = Fluent::Engine.now
    rh = @resolved_host
    if !rh || now - @resolved_time >= @sender.expire_dns_cache
      rh = @resolved_host = resolve_dns!
      @resolved_time = now
    end
    rh
  end
end

#send_data(tag, chunk) ⇒ Object 



625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
 
# File 'lib/fluent/plugin/out_forward.rb', line 625

def send_data(tag, chunk)
  sock = @sender.create_transfer_socket(resolved_host, port, @hostname)
  begin
    send_data_actual(sock, tag, chunk)
  rescue
    sock.close rescue nil
    raise
  end

  if @sender.require_ack_response
    return sock # to read ACK from socket
  end

  sock.close_write rescue nil
  sock.close rescue nil
  heartbeat(false)
  nil
end

#send_data_actual(sock, tag, chunk) ⇒ Object 



594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
 
# File 'lib/fluent/plugin/out_forward.rb', line 594

def send_data_actual(sock, tag, chunk)
  @state = @sender.security ? :helo : :established
  if @state != :established
    establish_connection(sock)
  end

  unless available?
    raise ConnectionClosedError, "failed to establish connection with node #{@name}"
  end

  option = { 'size' => chunk.size, 'compressed' => @compress }
  option['chunk'] = Base64.encode64(chunk.unique_id) if @sender.require_ack_response

  # https://github.com/fluent/fluentd/wiki/Forward-Protocol-Specification-v1#packedforward-mode
  # out_forward always uses str32 type for entries.
  # str16 can store only 64kbytes, and it should be much smaller than buffer chunk size.

  tag = tag.dup.force_encoding(Encoding::UTF_8)

  sock.write @sender.forward_header                    # array, size=3
  sock.write tag.to_msgpack                            # 1. tag: String (str)
  chunk.open(compressed: @compress) do |chunk_io|
    entries = [0xdb, chunk_io.size].pack('CN')
    sock.write entries.force_encoding(Encoding::UTF_8) # 2. entries: String (str32)
    IO.copy_stream(chunk_io, sock)                     #    writeRawBody(packed_es)
  end
  sock.write option.to_msgpack                         # 3. option: Hash(map)

  # TODO: use bin32 for non-utf8 content(entries) when old msgpack-ruby (0.5.x or earlier) not supported
end

#send_heartbeat ⇒ Object

FORWARD_TCP_HEARTBEAT_DATA = FORWARD_HEADER + ”.to_msgpack + [].to_msgpack



645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
 
# File 'lib/fluent/plugin/out_forward.rb', line 645

def send_heartbeat
  begin
    dest_addr = resolved_host
    @resolved_once = true
  rescue ::SocketError => e
    if !@resolved_once && @sender.ignore_network_errors_at_startup
      @log.warn "failed to resolve node name in heartbeating", server: @name || @host, error: e
      return
    end
    raise
  end

  case @sender.heartbeat_type
  when :transport
    @sender.create_transfer_socket(dest_addr, port, @hostname) do |sock|
      ## don't send any data to not cause a compatibility problem
      # sock.write FORWARD_TCP_HEARTBEAT_DATA

      # successful tcp connection establishment is considered as valid heartbeat
      heartbeat(true)
    end
  when :udp
    @usock.send "\0", 0, Socket.pack_sockaddr_in(@port, resolved_host)
  when :none # :none doesn't use this class
    raise "BUG: heartbeat_type none must not use Node"
  else
    raise "BUG: unknown heartbeat_type '#{@sender.heartbeat_type}'"
  end
end

#standby? ⇒ Boolean

Returns:



560
561
562
 
# File 'lib/fluent/plugin/out_forward.rb', line 560

def standby?
  @standby
end

#tick ⇒ Object 



704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
 
# File 'lib/fluent/plugin/out_forward.rb', line 704

def tick
  now = Time.now.to_f
  if !@available
    if @failure.hard_timeout?(now)
      @failure.clear
    end
    return nil
  end

  if @failure.hard_timeout?(now)
    @log.warn "detached forwarding server '#{@name}'", host: @host, port: @port, hard_timeout: true
    @available = false
    @resolved_host = nil  # expire cached host
    @failure.clear
    return true
  end

  if @sender.phi_failure_detector
    phi = @failure.phi(now)
    if phi > @sender.phi_threshold
      @log.warn "detached forwarding server '#{@name}'", host: @host, port: @port, phi: phi, phi_threshold: @sender.phi_threshold
      @available = false
      @resolved_host = nil  # expire cached host
      @failure.clear
      return true
    end
  end
  false
end

#validate_host_resolution! ⇒ Object 



548
549
550
 
# File 'lib/fluent/plugin/out_forward.rb', line 548

def validate_host_resolution!
  resolved_host
end