forked from hashicorp/consul
/
server.go
1110 lines (939 loc) · 33.6 KB
/
server.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
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
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
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
593
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
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
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
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
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
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
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
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
package consul
import (
"crypto/tls"
"errors"
"fmt"
"io"
"io/ioutil"
"log"
"net"
"net/rpc"
"os"
"path/filepath"
"reflect"
"strconv"
"sync"
"sync/atomic"
"time"
"github.com/hashicorp/consul/acl"
"github.com/hashicorp/consul/agent/consul/autopilot"
"github.com/hashicorp/consul/agent/consul/fsm"
"github.com/hashicorp/consul/agent/consul/state"
"github.com/hashicorp/consul/agent/metadata"
"github.com/hashicorp/consul/agent/pool"
"github.com/hashicorp/consul/agent/router"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/agent/token"
"github.com/hashicorp/consul/lib"
"github.com/hashicorp/consul/sentinel"
"github.com/hashicorp/consul/tlsutil"
"github.com/hashicorp/consul/types"
"github.com/hashicorp/raft"
raftboltdb "github.com/hashicorp/raft-boltdb"
"github.com/hashicorp/serf/coordinate"
"github.com/hashicorp/serf/serf"
)
// These are the protocol versions that Consul can _understand_. These are
// Consul-level protocol versions, that are used to configure the Serf
// protocol versions.
const (
ProtocolVersionMin uint8 = 2
// Version 3 added support for network coordinates but we kept the
// default protocol version at 2 to ease the transition to this new
// feature. A Consul agent speaking version 2 of the protocol will
// attempt to send its coordinates to a server who understands version
// 3 or greater.
ProtocolVersion2Compatible = 2
ProtocolVersionMax = 3
)
const (
serfLANSnapshot = "serf/local.snapshot"
serfWANSnapshot = "serf/remote.snapshot"
raftState = "raft/"
snapshotsRetained = 2
// serverRPCCache controls how long we keep an idle connection
// open to a server
serverRPCCache = 2 * time.Minute
// serverMaxStreams controls how many idle streams we keep
// open to a server
serverMaxStreams = 64
// raftLogCacheSize is the maximum number of logs to cache in-memory.
// This is used to reduce disk I/O for the recently committed entries.
raftLogCacheSize = 512
// raftRemoveGracePeriod is how long we wait to allow a RemovePeer
// to replicate to gracefully leave the cluster.
raftRemoveGracePeriod = 5 * time.Second
)
// Server is Consul server which manages the service discovery,
// health checking, DC forwarding, Raft, and multiple Serf pools.
type Server struct {
// sentinel is the Sentinel code engine (can be nil).
sentinel sentinel.Evaluator
// aclAuthCache is the authoritative ACL cache.
aclAuthCache *acl.Cache
// aclCache is the non-authoritative ACL cache.
aclCache *aclCache
// autopilot is the Autopilot instance for this server.
autopilot *autopilot.Autopilot
// autopilotWaitGroup is used to block until Autopilot shuts down.
autopilotWaitGroup sync.WaitGroup
// Consul configuration
config *Config
// tokens holds ACL tokens initially from the configuration, but can
// be updated at runtime, so should always be used instead of going to
// the configuration directly.
tokens *token.Store
// Connection pool to other consul servers
connPool *pool.ConnPool
// eventChLAN is used to receive events from the
// serf cluster in the datacenter
eventChLAN chan serf.Event
// eventChWAN is used to receive events from the
// serf cluster that spans datacenters
eventChWAN chan serf.Event
// fsm is the state machine used with Raft to provide
// strong consistency.
fsm *fsm.FSM
// Logger uses the provided LogOutput
logger *log.Logger
// The raft instance is used among Consul nodes within the DC to protect
// operations that require strong consistency.
// the state directly.
raft *raft.Raft
raftLayer *RaftLayer
raftStore *raftboltdb.BoltStore
raftTransport *raft.NetworkTransport
raftInmem *raft.InmemStore
// raftNotifyCh is set up by setupRaft() and ensures that we get reliable leader
// transition notifications from the Raft layer.
raftNotifyCh <-chan bool
// reconcileCh is used to pass events from the serf handler
// into the leader manager, so that the strong state can be
// updated
reconcileCh chan serf.Member
// readyForConsistentReads is used to track when the leader server is
// ready to serve consistent reads, after it has applied its initial
// barrier. This is updated atomically.
readyForConsistentReads int32
// leaveCh is used to signal that the server is leaving the cluster
// and trying to shed its RPC traffic onto other Consul servers. This
// is only ever closed.
leaveCh chan struct{}
// router is used to map out Consul servers in the WAN and in Consul
// Enterprise user-defined areas.
router *router.Router
// Listener is used to listen for incoming connections
Listener net.Listener
rpcServer *rpc.Server
// rpcTLS is the TLS config for incoming TLS requests
rpcTLS *tls.Config
// serfLAN is the Serf cluster maintained inside the DC
// which contains all the DC nodes
serfLAN *serf.Serf
// segmentLAN maps segment names to their Serf cluster
segmentLAN map[string]*serf.Serf
// serfWAN is the Serf cluster maintained between DC's
// which SHOULD only consist of Consul servers
serfWAN *serf.Serf
// serverLookup tracks server consuls in the local datacenter.
// Used to do leader forwarding and provide fast lookup by server id and address
serverLookup *ServerLookup
// floodLock controls access to floodCh.
floodLock sync.RWMutex
floodCh []chan struct{}
// sessionTimers track the expiration time of each Session that has
// a TTL. On expiration, a SessionDestroy event will occur, and
// destroy the session via standard session destroy processing
sessionTimers *SessionTimers
// statsFetcher is used by autopilot to check the status of the other
// Consul router.
statsFetcher *StatsFetcher
// reassertLeaderCh is used to signal the leader loop should re-run
// leadership actions after a snapshot restore.
reassertLeaderCh chan chan error
// tombstoneGC is used to track the pending GC invocations
// for the KV tombstones
tombstoneGC *state.TombstoneGC
// aclReplicationStatus (and its associated lock) provide information
// about the health of the ACL replication goroutine.
aclReplicationStatus structs.ACLReplicationStatus
aclReplicationStatusLock sync.RWMutex
// shutdown and the associated members here are used in orchestrating
// a clean shutdown. The shutdownCh is never written to, only closed to
// indicate a shutdown has been initiated.
shutdown bool
shutdownCh chan struct{}
shutdownLock sync.Mutex
}
func NewServer(config *Config) (*Server, error) {
return NewServerLogger(config, nil, new(token.Store))
}
// NewServer is used to construct a new Consul server from the
// configuration, potentially returning an error
func NewServerLogger(config *Config, logger *log.Logger, tokens *token.Store) (*Server, error) {
// Check the protocol version.
if err := config.CheckProtocolVersion(); err != nil {
return nil, err
}
// Check for a data directory.
if config.DataDir == "" && !config.DevMode {
return nil, fmt.Errorf("Config must provide a DataDir")
}
// Sanity check the ACLs.
if err := config.CheckACL(); err != nil {
return nil, err
}
// Ensure we have a log output and create a logger.
if config.LogOutput == nil {
config.LogOutput = os.Stderr
}
if logger == nil {
logger = log.New(config.LogOutput, "", log.LstdFlags)
}
// Check if TLS is enabled
if config.CAFile != "" || config.CAPath != "" {
config.UseTLS = true
}
// Create the TLS wrapper for outgoing connections.
tlsConf := config.tlsConfig()
tlsWrap, err := tlsConf.OutgoingTLSWrapper()
if err != nil {
return nil, err
}
// Get the incoming TLS config.
incomingTLS, err := tlsConf.IncomingTLSConfig()
if err != nil {
return nil, err
}
// Create the tombstone GC.
gc, err := state.NewTombstoneGC(config.TombstoneTTL, config.TombstoneTTLGranularity)
if err != nil {
return nil, err
}
// Create the shutdown channel - this is closed but never written to.
shutdownCh := make(chan struct{})
connPool := &pool.ConnPool{
SrcAddr: config.RPCSrcAddr,
LogOutput: config.LogOutput,
MaxTime: serverRPCCache,
MaxStreams: serverMaxStreams,
TLSWrapper: tlsWrap,
ForceTLS: config.VerifyOutgoing,
}
// Create server.
s := &Server{
config: config,
tokens: tokens,
connPool: connPool,
eventChLAN: make(chan serf.Event, 256),
eventChWAN: make(chan serf.Event, 256),
logger: logger,
leaveCh: make(chan struct{}),
reconcileCh: make(chan serf.Member, 32),
router: router.NewRouter(logger, config.Datacenter),
rpcServer: rpc.NewServer(),
rpcTLS: incomingTLS,
reassertLeaderCh: make(chan chan error),
segmentLAN: make(map[string]*serf.Serf, len(config.Segments)),
sessionTimers: NewSessionTimers(),
tombstoneGC: gc,
serverLookup: NewServerLookup(),
shutdownCh: shutdownCh,
}
// Initialize the stats fetcher that autopilot will use.
s.statsFetcher = NewStatsFetcher(logger, s.connPool, s.config.Datacenter)
// Initialize the authoritative ACL cache.
s.sentinel = sentinel.New(logger)
s.aclAuthCache, err = acl.NewCache(aclCacheSize, s.aclLocalFault, s.sentinel)
if err != nil {
s.Shutdown()
return nil, fmt.Errorf("Failed to create authoritative ACL cache: %v", err)
}
// Set up the non-authoritative ACL cache. A nil local function is given
// if ACL replication isn't enabled.
var local acl.FaultFunc
if s.IsACLReplicationEnabled() {
local = s.aclLocalFault
}
if s.aclCache, err = newACLCache(config, logger, s.RPC, local, s.sentinel); err != nil {
s.Shutdown()
return nil, fmt.Errorf("Failed to create non-authoritative ACL cache: %v", err)
}
// Initialize the RPC layer.
if err := s.setupRPC(tlsWrap); err != nil {
s.Shutdown()
return nil, fmt.Errorf("Failed to start RPC layer: %v", err)
}
// Initialize any extra RPC listeners for segments.
segmentListeners, err := s.setupSegmentRPC()
if err != nil {
s.Shutdown()
return nil, fmt.Errorf("Failed to start segment RPC layer: %v", err)
}
// Initialize the Raft server.
if err := s.setupRaft(); err != nil {
s.Shutdown()
return nil, fmt.Errorf("Failed to start Raft: %v", err)
}
// Serf and dynamic bind ports
//
// The LAN serf cluster announces the port of the WAN serf cluster
// which creates a race when the WAN cluster is supposed to bind to
// a dynamic port (port 0). The current memberlist implementation will
// update the bind port in the configuration after the memberlist is
// created, so we can pull it out from there reliably, even though it's
// a little gross to be reading the updated config.
// Initialize the WAN Serf.
serfBindPortWAN := config.SerfWANConfig.MemberlistConfig.BindPort
s.serfWAN, err = s.setupSerf(config.SerfWANConfig, s.eventChWAN, serfWANSnapshot, true, serfBindPortWAN, "", s.Listener)
if err != nil {
s.Shutdown()
return nil, fmt.Errorf("Failed to start WAN Serf: %v", err)
}
// See big comment above why we are doing this.
if serfBindPortWAN == 0 {
serfBindPortWAN = config.SerfWANConfig.MemberlistConfig.BindPort
if serfBindPortWAN == 0 {
return nil, fmt.Errorf("Failed to get dynamic bind port for WAN Serf")
}
s.logger.Printf("[INFO] agent: Serf WAN TCP bound to port %d", serfBindPortWAN)
}
// Initialize the LAN segments before the default LAN Serf so we have
// updated port information to publish there.
if err := s.setupSegments(config, serfBindPortWAN, segmentListeners); err != nil {
s.Shutdown()
return nil, fmt.Errorf("Failed to setup network segments: %v", err)
}
// Initialize the LAN Serf for the default network segment.
s.serfLAN, err = s.setupSerf(config.SerfLANConfig, s.eventChLAN, serfLANSnapshot, false, serfBindPortWAN, "", s.Listener)
if err != nil {
s.Shutdown()
return nil, fmt.Errorf("Failed to start LAN Serf: %v", err)
}
go s.lanEventHandler()
// Start the flooders after the LAN event handler is wired up.
s.floodSegments(config)
// Add a "static route" to the WAN Serf and hook it up to Serf events.
if err := s.router.AddArea(types.AreaWAN, s.serfWAN, s.connPool, s.config.VerifyOutgoing); err != nil {
s.Shutdown()
return nil, fmt.Errorf("Failed to add WAN serf route: %v", err)
}
go router.HandleSerfEvents(s.logger, s.router, types.AreaWAN, s.serfWAN.ShutdownCh(), s.eventChWAN)
// Fire up the LAN <-> WAN join flooder.
portFn := func(s *metadata.Server) (int, bool) {
if s.WanJoinPort > 0 {
return s.WanJoinPort, true
}
return 0, false
}
go s.Flood(nil, portFn, s.serfWAN)
// Start monitoring leadership. This must happen after Serf is set up
// since it can fire events when leadership is obtained.
go s.monitorLeadership()
// Start ACL replication.
if s.IsACLReplicationEnabled() {
go s.runACLReplication()
}
// Start listening for RPC requests.
go s.listen(s.Listener)
// Start listeners for any segments with separate RPC listeners.
for _, listener := range segmentListeners {
go s.listen(listener)
}
// Start the metrics handlers.
go s.sessionStats()
// Initialize Autopilot
s.initAutopilot(config)
return s, nil
}
// setupRaft is used to setup and initialize Raft
func (s *Server) setupRaft() error {
// If we have an unclean exit then attempt to close the Raft store.
defer func() {
if s.raft == nil && s.raftStore != nil {
if err := s.raftStore.Close(); err != nil {
s.logger.Printf("[ERR] consul: failed to close Raft store: %v", err)
}
}
}()
// Create the FSM.
var err error
s.fsm, err = fsm.New(s.tombstoneGC, s.config.LogOutput)
if err != nil {
return err
}
var serverAddressProvider raft.ServerAddressProvider = nil
if s.config.RaftConfig.ProtocolVersion >= 3 { //ServerAddressProvider needs server ids to work correctly, which is only supported in protocol version 3 or higher
serverAddressProvider = s.serverLookup
}
// Create a transport layer.
transConfig := &raft.NetworkTransportConfig{
Stream: s.raftLayer,
MaxPool: 3,
Timeout: 10 * time.Second,
ServerAddressProvider: serverAddressProvider,
}
trans := raft.NewNetworkTransportWithConfig(transConfig)
s.raftTransport = trans
// Make sure we set the LogOutput.
s.config.RaftConfig.LogOutput = s.config.LogOutput
s.config.RaftConfig.Logger = s.logger
// Versions of the Raft protocol below 3 require the LocalID to match the network
// address of the transport.
s.config.RaftConfig.LocalID = raft.ServerID(trans.LocalAddr())
if s.config.RaftConfig.ProtocolVersion >= 3 {
s.config.RaftConfig.LocalID = raft.ServerID(s.config.NodeID)
}
// Build an all in-memory setup for dev mode, otherwise prepare a full
// disk-based setup.
var log raft.LogStore
var stable raft.StableStore
var snap raft.SnapshotStore
if s.config.DevMode {
store := raft.NewInmemStore()
s.raftInmem = store
stable = store
log = store
snap = raft.NewInmemSnapshotStore()
} else {
// Create the base raft path.
path := filepath.Join(s.config.DataDir, raftState)
if err := lib.EnsurePath(path, true); err != nil {
return err
}
// Create the backend raft store for logs and stable storage.
store, err := raftboltdb.NewBoltStore(filepath.Join(path, "raft.db"))
if err != nil {
return err
}
s.raftStore = store
stable = store
// Wrap the store in a LogCache to improve performance.
cacheStore, err := raft.NewLogCache(raftLogCacheSize, store)
if err != nil {
return err
}
log = cacheStore
// Create the snapshot store.
snapshots, err := raft.NewFileSnapshotStore(path, snapshotsRetained, s.config.LogOutput)
if err != nil {
return err
}
snap = snapshots
// For an existing cluster being upgraded to the new version of
// Raft, we almost never want to run recovery based on the old
// peers.json file. We create a peers.info file with a helpful
// note about where peers.json went, and use that as a sentinel
// to avoid ingesting the old one that first time (if we have to
// create the peers.info file because it's not there, we also
// blow away any existing peers.json file).
peersFile := filepath.Join(path, "peers.json")
peersInfoFile := filepath.Join(path, "peers.info")
if _, err := os.Stat(peersInfoFile); os.IsNotExist(err) {
if err := ioutil.WriteFile(peersInfoFile, []byte(peersInfoContent), 0755); err != nil {
return fmt.Errorf("failed to write peers.info file: %v", err)
}
// Blow away the peers.json file if present, since the
// peers.info sentinel wasn't there.
if _, err := os.Stat(peersFile); err == nil {
if err := os.Remove(peersFile); err != nil {
return fmt.Errorf("failed to delete peers.json, please delete manually (see peers.info for details): %v", err)
}
s.logger.Printf("[INFO] consul: deleted peers.json file (see peers.info for details)")
}
} else if _, err := os.Stat(peersFile); err == nil {
s.logger.Printf("[INFO] consul: found peers.json file, recovering Raft configuration...")
var configuration raft.Configuration
if s.config.RaftConfig.ProtocolVersion < 3 {
configuration, err = raft.ReadPeersJSON(peersFile)
} else {
configuration, err = raft.ReadConfigJSON(peersFile)
}
if err != nil {
return fmt.Errorf("recovery failed to parse peers.json: %v", err)
}
tmpFsm, err := fsm.New(s.tombstoneGC, s.config.LogOutput)
if err != nil {
return fmt.Errorf("recovery failed to make temp FSM: %v", err)
}
if err := raft.RecoverCluster(s.config.RaftConfig, tmpFsm,
log, stable, snap, trans, configuration); err != nil {
return fmt.Errorf("recovery failed: %v", err)
}
if err := os.Remove(peersFile); err != nil {
return fmt.Errorf("recovery failed to delete peers.json, please delete manually (see peers.info for details): %v", err)
}
s.logger.Printf("[INFO] consul: deleted peers.json file after successful recovery")
}
}
// If we are in bootstrap or dev mode and the state is clean then we can
// bootstrap now.
if s.config.Bootstrap || s.config.DevMode {
hasState, err := raft.HasExistingState(log, stable, snap)
if err != nil {
return err
}
if !hasState {
configuration := raft.Configuration{
Servers: []raft.Server{
raft.Server{
ID: s.config.RaftConfig.LocalID,
Address: trans.LocalAddr(),
},
},
}
if err := raft.BootstrapCluster(s.config.RaftConfig,
log, stable, snap, trans, configuration); err != nil {
return err
}
}
}
// Set up a channel for reliable leader notifications.
raftNotifyCh := make(chan bool, 1)
s.config.RaftConfig.NotifyCh = raftNotifyCh
s.raftNotifyCh = raftNotifyCh
// Setup the Raft store.
s.raft, err = raft.NewRaft(s.config.RaftConfig, s.fsm, log, stable, snap, trans)
if err != nil {
return err
}
return nil
}
// endpointFactory is a function that returns an RPC endpoint bound to the given
// server.
type factory func(s *Server) interface{}
// endpoints is a list of registered RPC endpoint factories.
var endpoints []factory
// registerEndpoint registers a new RPC endpoint factory.
func registerEndpoint(fn factory) {
endpoints = append(endpoints, fn)
}
// setupRPC is used to setup the RPC listener
func (s *Server) setupRPC(tlsWrap tlsutil.DCWrapper) error {
for _, fn := range endpoints {
s.rpcServer.Register(fn(s))
}
ln, err := net.ListenTCP("tcp", s.config.RPCAddr)
if err != nil {
return err
}
s.Listener = ln
if s.config.NotifyListen != nil {
s.config.NotifyListen()
}
// todo(fs): we should probably guard this
if s.config.RPCAdvertise == nil {
s.config.RPCAdvertise = ln.Addr().(*net.TCPAddr)
}
// Verify that we have a usable advertise address
if s.config.RPCAdvertise.IP.IsUnspecified() {
ln.Close()
return fmt.Errorf("RPC advertise address is not advertisable: %v", s.config.RPCAdvertise)
}
// Provide a DC specific wrapper. Raft replication is only
// ever done in the same datacenter, so we can provide it as a constant.
wrapper := tlsutil.SpecificDC(s.config.Datacenter, tlsWrap)
// Define a callback for determining whether to wrap a connection with TLS
tlsFunc := func(address raft.ServerAddress) bool {
if s.config.VerifyOutgoing {
return true
}
server := s.serverLookup.Server(address)
if server == nil {
return false
}
return server.UseTLS
}
s.raftLayer = NewRaftLayer(s.config.RPCSrcAddr, s.config.RPCAdvertise, wrapper, tlsFunc)
return nil
}
// Shutdown is used to shutdown the server
func (s *Server) Shutdown() error {
s.logger.Printf("[INFO] consul: shutting down server")
s.shutdownLock.Lock()
defer s.shutdownLock.Unlock()
if s.shutdown {
return nil
}
s.shutdown = true
close(s.shutdownCh)
if s.serfLAN != nil {
s.serfLAN.Shutdown()
}
if s.serfWAN != nil {
s.serfWAN.Shutdown()
if err := s.router.RemoveArea(types.AreaWAN); err != nil {
s.logger.Printf("[WARN] consul: error removing WAN area: %v", err)
}
}
s.router.Shutdown()
if s.raft != nil {
s.raftTransport.Close()
s.raftLayer.Close()
future := s.raft.Shutdown()
if err := future.Error(); err != nil {
s.logger.Printf("[WARN] consul: error shutting down raft: %s", err)
}
if s.raftStore != nil {
s.raftStore.Close()
}
}
if s.Listener != nil {
s.Listener.Close()
}
// Close the connection pool
s.connPool.Shutdown()
return nil
}
// Leave is used to prepare for a graceful shutdown of the server
func (s *Server) Leave() error {
s.logger.Printf("[INFO] consul: server starting leave")
// Check the number of known peers
numPeers, err := s.numPeers()
if err != nil {
s.logger.Printf("[ERR] consul: failed to check raft peers: %v", err)
return err
}
addr := s.raftTransport.LocalAddr()
// If we are the current leader, and we have any other peers (cluster has multiple
// servers), we should do a RemoveServer/RemovePeer to safely reduce the quorum size.
// If we are not the leader, then we should issue our leave intention and wait to be
// removed for some sane period of time.
isLeader := s.IsLeader()
if isLeader && numPeers > 1 {
minRaftProtocol, err := s.autopilot.MinRaftProtocol()
if err != nil {
return err
}
if minRaftProtocol >= 2 && s.config.RaftConfig.ProtocolVersion >= 3 {
future := s.raft.RemoveServer(raft.ServerID(s.config.NodeID), 0, 0)
if err := future.Error(); err != nil {
s.logger.Printf("[ERR] consul: failed to remove ourself as raft peer: %v", err)
}
} else {
future := s.raft.RemovePeer(addr)
if err := future.Error(); err != nil {
s.logger.Printf("[ERR] consul: failed to remove ourself as raft peer: %v", err)
}
}
}
// Leave the WAN pool
if s.serfWAN != nil {
if err := s.serfWAN.Leave(); err != nil {
s.logger.Printf("[ERR] consul: failed to leave WAN Serf cluster: %v", err)
}
}
// Leave the LAN pool
if s.serfLAN != nil {
if err := s.serfLAN.Leave(); err != nil {
s.logger.Printf("[ERR] consul: failed to leave LAN Serf cluster: %v", err)
}
}
// Start refusing RPCs now that we've left the LAN pool. It's important
// to do this *after* we've left the LAN pool so that clients will know
// to shift onto another server if they perform a retry. We also wake up
// all queries in the RPC retry state.
s.logger.Printf("[INFO] consul: Waiting %s to drain RPC traffic", s.config.LeaveDrainTime)
close(s.leaveCh)
time.Sleep(s.config.LeaveDrainTime)
// If we were not leader, wait to be safely removed from the cluster. We
// must wait to allow the raft replication to take place, otherwise an
// immediate shutdown could cause a loss of quorum.
if !isLeader {
left := false
limit := time.Now().Add(raftRemoveGracePeriod)
for !left && time.Now().Before(limit) {
// Sleep a while before we check.
time.Sleep(50 * time.Millisecond)
// Get the latest configuration.
future := s.raft.GetConfiguration()
if err := future.Error(); err != nil {
s.logger.Printf("[ERR] consul: failed to get raft configuration: %v", err)
break
}
// See if we are no longer included.
left = true
for _, server := range future.Configuration().Servers {
if server.Address == addr {
left = false
break
}
}
}
// TODO (slackpad) With the old Raft library we used to force the
// peers set to empty when a graceful leave occurred. This would
// keep voting spam down if the server was restarted, but it was
// dangerous because the peers was inconsistent with the logs and
// snapshots, so it wasn't really safe in all cases for the server
// to become leader. This is now safe, but the log spam is noisy.
// The next new version of the library will have a "you are not a
// peer stop it" behavior that should address this. We will have
// to evaluate during the RC period if this interim situation is
// not too confusing for operators.
// TODO (slackpad) When we take a later new version of the Raft
// library it won't try to complete replication, so this peer
// may not realize that it has been removed. Need to revisit this
// and the warning here.
if !left {
s.logger.Printf("[WARN] consul: failed to leave raft configuration gracefully, timeout")
}
}
return nil
}
// numPeers is used to check on the number of known peers, including potentially
// the local node. We count only voters, since others can't actually become
// leader, so aren't considered peers.
func (s *Server) numPeers() (int, error) {
future := s.raft.GetConfiguration()
if err := future.Error(); err != nil {
return 0, err
}
return autopilot.NumPeers(future.Configuration()), nil
}
// JoinLAN is used to have Consul join the inner-DC pool
// The target address should be another node inside the DC
// listening on the Serf LAN address
func (s *Server) JoinLAN(addrs []string) (int, error) {
return s.serfLAN.Join(addrs, true)
}
// JoinWAN is used to have Consul join the cross-WAN Consul ring
// The target address should be another node listening on the
// Serf WAN address
func (s *Server) JoinWAN(addrs []string) (int, error) {
return s.serfWAN.Join(addrs, true)
}
// LocalMember is used to return the local node
func (s *Server) LocalMember() serf.Member {
return s.serfLAN.LocalMember()
}
// LANMembers is used to return the members of the LAN cluster
func (s *Server) LANMembers() []serf.Member {
return s.serfLAN.Members()
}
// WANMembers is used to return the members of the LAN cluster
func (s *Server) WANMembers() []serf.Member {
return s.serfWAN.Members()
}
// RemoveFailedNode is used to remove a failed node from the cluster
func (s *Server) RemoveFailedNode(node string) error {
if err := s.serfLAN.RemoveFailedNode(node); err != nil {
return err
}
if err := s.serfWAN.RemoveFailedNode(node); err != nil {
return err
}
return nil
}
// IsLeader checks if this server is the cluster leader
func (s *Server) IsLeader() bool {
return s.raft.State() == raft.Leader
}
// KeyManagerLAN returns the LAN Serf keyring manager
func (s *Server) KeyManagerLAN() *serf.KeyManager {
return s.serfLAN.KeyManager()
}
// KeyManagerWAN returns the WAN Serf keyring manager
func (s *Server) KeyManagerWAN() *serf.KeyManager {
return s.serfWAN.KeyManager()
}
// Encrypted determines if gossip is encrypted
func (s *Server) Encrypted() bool {
return s.serfLAN.EncryptionEnabled() && s.serfWAN.EncryptionEnabled()
}
// LANSegments returns a map of LAN segments by name
func (s *Server) LANSegments() map[string]*serf.Serf {
segments := make(map[string]*serf.Serf, len(s.segmentLAN)+1)
segments[""] = s.serfLAN
for name, segment := range s.segmentLAN {
segments[name] = segment
}
return segments
}
// inmemCodec is used to do an RPC call without going over a network
type inmemCodec struct {
method string
args interface{}
reply interface{}
err error
}
func (i *inmemCodec) ReadRequestHeader(req *rpc.Request) error {
req.ServiceMethod = i.method
return nil
}
func (i *inmemCodec) ReadRequestBody(args interface{}) error {
sourceValue := reflect.Indirect(reflect.Indirect(reflect.ValueOf(i.args)))
dst := reflect.Indirect(reflect.Indirect(reflect.ValueOf(args)))
dst.Set(sourceValue)
return nil
}
func (i *inmemCodec) WriteResponse(resp *rpc.Response, reply interface{}) error {
if resp.Error != "" {
i.err = errors.New(resp.Error)
return nil
}
sourceValue := reflect.Indirect(reflect.Indirect(reflect.ValueOf(reply)))
dst := reflect.Indirect(reflect.Indirect(reflect.ValueOf(i.reply)))
dst.Set(sourceValue)
return nil
}
func (i *inmemCodec) Close() error {
return nil
}
// RPC is used to make a local RPC call
func (s *Server) RPC(method string, args interface{}, reply interface{}) error {
codec := &inmemCodec{
method: method,
args: args,
reply: reply,
}
if err := s.rpcServer.ServeRequest(codec); err != nil {
return err
}
return codec.err
}
// SnapshotRPC dispatches the given snapshot request, reading from the streaming
// input and writing to the streaming output depending on the operation.
func (s *Server) SnapshotRPC(args *structs.SnapshotRequest, in io.Reader, out io.Writer,
replyFn structs.SnapshotReplyFn) error {
// Perform the operation.
var reply structs.SnapshotResponse
snap, err := s.dispatchSnapshotRequest(args, in, &reply)
if err != nil {
return err
}
defer func() {
if err := snap.Close(); err != nil {
s.logger.Printf("[ERR] consul: Failed to close snapshot: %v", err)
}
}()
// Let the caller peek at the reply.
if replyFn != nil {
if err := replyFn(&reply); err != nil {
return nil
}
}
// Stream the snapshot.
if out != nil {
if _, err := io.Copy(out, snap); err != nil {
return fmt.Errorf("failed to stream snapshot: %v", err)
}
}
return nil
}
// RegisterEndpoint is used to substitute an endpoint for testing.
func (s *Server) RegisterEndpoint(name string, handler interface{}) error {
s.logger.Printf("[WARN] consul: endpoint injected; this should only be used for testing")
return s.rpcServer.RegisterName(name, handler)
}
// Stats is used to return statistics for debugging and insight
// for various sub-systems
func (s *Server) Stats() map[string]map[string]string {
toString := func(v uint64) string {
return strconv.FormatUint(v, 10)
}
numKnownDCs := len(s.router.GetDatacenters())
stats := map[string]map[string]string{
"consul": map[string]string{
"server": "true",
"leader": fmt.Sprintf("%v", s.IsLeader()),
"leader_addr": string(s.raft.Leader()),
"bootstrap": fmt.Sprintf("%v", s.config.Bootstrap),
"known_datacenters": toString(uint64(numKnownDCs)),
},
"raft": s.raft.Stats(),
"serf_lan": s.serfLAN.Stats(),
"serf_wan": s.serfWAN.Stats(),
"runtime": runtimeStats(),
}