-
Notifications
You must be signed in to change notification settings - Fork 1.1k
/
client.go
1922 lines (1675 loc) · 56.7 KB
/
client.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
// Copyright 2012-present Oliver Eilhard. All rights reserved.
// Use of this source code is governed by a MIT-license.
// See http://olivere.mit-license.org/license.txt for details.
package elastic
import (
"bytes"
"context"
"encoding/json"
"fmt"
"log"
"net/http"
"net/http/httputil"
"net/url"
"os"
"regexp"
"strings"
"sync"
"time"
"github.com/pkg/errors"
"gopkg.in/olivere/elastic.v5/config"
)
const (
// Version is the current version of Elastic.
Version = "5.0.86"
// DefaultURL is the default endpoint of Elasticsearch on the local machine.
// It is used e.g. when initializing a new Client without a specific URL.
DefaultURL = "http://127.0.0.1:9200"
// DefaultScheme is the default protocol scheme to use when sniffing
// the Elasticsearch cluster.
DefaultScheme = "http"
// DefaultHealthcheckEnabled specifies if healthchecks are enabled by default.
DefaultHealthcheckEnabled = true
// DefaultHealthcheckTimeoutStartup is the time the healthcheck waits
// for a response from Elasticsearch on startup, i.e. when creating a
// client. After the client is started, a shorter timeout is commonly used
// (its default is specified in DefaultHealthcheckTimeout).
DefaultHealthcheckTimeoutStartup = 5 * time.Second
// DefaultHealthcheckTimeout specifies the time a running client waits for
// a response from Elasticsearch. Notice that the healthcheck timeout
// when a client is created is larger by default (see DefaultHealthcheckTimeoutStartup).
DefaultHealthcheckTimeout = 1 * time.Second
// DefaultHealthcheckInterval is the default interval between
// two health checks of the nodes in the cluster.
DefaultHealthcheckInterval = 60 * time.Second
// DefaultSnifferEnabled specifies if the sniffer is enabled by default.
DefaultSnifferEnabled = true
// DefaultSnifferInterval is the interval between two sniffing procedures,
// i.e. the lookup of all nodes in the cluster and their addition/removal
// from the list of actual connections.
DefaultSnifferInterval = 15 * time.Minute
// DefaultSnifferTimeoutStartup is the default timeout for the sniffing
// process that is initiated while creating a new client. For subsequent
// sniffing processes, DefaultSnifferTimeout is used (by default).
DefaultSnifferTimeoutStartup = 5 * time.Second
// DefaultSnifferTimeout is the default timeout after which the
// sniffing process times out. Notice that for the initial sniffing
// process, DefaultSnifferTimeoutStartup is used.
DefaultSnifferTimeout = 2 * time.Second
// DefaultSendGetBodyAs is the HTTP method to use when elastic is sending
// a GET request with a body.
DefaultSendGetBodyAs = "GET"
// DefaultGzipEnabled specifies if gzip compression is enabled by default.
DefaultGzipEnabled = false
// off is used to disable timeouts.
off = -1 * time.Second
)
var (
// ErrNoClient is raised when no Elasticsearch node is available.
ErrNoClient = errors.New("no Elasticsearch node available")
// ErrRetry is raised when a request cannot be executed after the configured
// number of retries.
ErrRetry = errors.New("cannot connect after several retries")
// ErrTimeout is raised when a request timed out, e.g. when WaitForStatus
// didn't return in time.
ErrTimeout = errors.New("timeout")
// noRetries is a retrier that does not retry.
noRetries = NewStopRetrier()
// noDeprecationLog is a no-op for logging deprecations.
noDeprecationLog = func(*http.Request, *http.Response) {}
)
// ClientOptionFunc is a function that configures a Client.
// It is used in NewClient.
type ClientOptionFunc func(*Client) error
// Client is an Elasticsearch client. Create one by calling NewClient.
type Client struct {
c *http.Client // net/http Client to use for requests
connsMu sync.RWMutex // connsMu guards the next block
conns []*conn // all connections
cindex int // index into conns
mu sync.RWMutex // guards the next block
urls []string // set of URLs passed initially to the client
running bool // true if the client's background processes are running
errorlog Logger // error log for critical messages
infolog Logger // information log for e.g. response times
tracelog Logger // trace log for debugging
deprecationlog func(*http.Request, *http.Response)
scheme string // http or https
healthcheckEnabled bool // healthchecks enabled or disabled
healthcheckTimeoutStartup time.Duration // time the healthcheck waits for a response from Elasticsearch on startup
healthcheckTimeout time.Duration // time the healthcheck waits for a response from Elasticsearch
healthcheckInterval time.Duration // interval between healthchecks
healthcheckStop chan bool // notify healthchecker to stop, and notify back
snifferEnabled bool // sniffer enabled or disabled
snifferTimeoutStartup time.Duration // time the sniffer waits for a response from nodes info API on startup
snifferTimeout time.Duration // time the sniffer waits for a response from nodes info API
snifferInterval time.Duration // interval between sniffing
snifferCallback SnifferCallback // callback to modify the sniffing decision
snifferStop chan bool // notify sniffer to stop, and notify back
decoder Decoder // used to decode data sent from Elasticsearch
basicAuth bool // indicates whether to send HTTP Basic Auth credentials
basicAuthUsername string // username for HTTP Basic Auth
basicAuthPassword string // password for HTTP Basic Auth
sendGetBodyAs string // override for when sending a GET with a body
requiredPlugins []string // list of required plugins
gzipEnabled bool // gzip compression enabled or disabled (default)
retrier Retrier // strategy for retries
headers http.Header // a list of default headers to add to each request
}
// NewClient creates a new client to work with Elasticsearch.
//
// NewClient, by default, is meant to be long-lived and shared across
// your application. If you need a short-lived client, e.g. for request-scope,
// consider using NewSimpleClient instead.
//
// The caller can configure the new client by passing configuration options
// to the func.
//
// Example:
//
// client, err := elastic.NewClient(
// elastic.SetURL("http://127.0.0.1:9200", "http://127.0.0.1:9201"),
// elastic.SetBasicAuth("user", "secret"))
//
// If no URL is configured, Elastic uses DefaultURL by default.
//
// If the sniffer is enabled (the default), the new client then sniffes
// the cluster via the Nodes Info API
// (see https://www.elastic.co/guide/en/elasticsearch/reference/5.2/cluster-nodes-info.html#cluster-nodes-info).
// It uses the URLs specified by the caller. The caller is responsible
// to only pass a list of URLs of nodes that belong to the same cluster.
// This sniffing process is run on startup and periodically.
// Use SnifferInterval to set the interval between two sniffs (default is
// 15 minutes). In other words: By default, the client will find new nodes
// in the cluster and remove those that are no longer available every
// 15 minutes. Disable the sniffer by passing SetSniff(false) to NewClient.
//
// The list of nodes found in the sniffing process will be used to make
// connections to the REST API of Elasticsearch. These nodes are also
// periodically checked in a shorter time frame. This process is called
// a health check. By default, a health check is done every 60 seconds.
// You can set a shorter or longer interval by SetHealthcheckInterval.
// Disabling health checks is not recommended, but can be done by
// SetHealthcheck(false).
//
// Connections are automatically marked as dead or healthy while
// making requests to Elasticsearch. When a request fails, Elastic will
// call into the Retry strategy which can be specified with SetRetry.
// The Retry strategy is also responsible for handling backoff i.e. the time
// to wait before starting the next request. There are various standard
// backoff implementations, e.g. ExponentialBackoff or SimpleBackoff.
// Retries are disabled by default.
//
// If no HttpClient is configured, then http.DefaultClient is used.
// You can use your own http.Client with some http.Transport for
// advanced scenarios.
//
// An error is also returned when some configuration option is invalid or
// the new client cannot sniff the cluster (if enabled).
func NewClient(options ...ClientOptionFunc) (*Client, error) {
// Set up the client
c := &Client{
c: http.DefaultClient,
conns: make([]*conn, 0),
cindex: -1,
scheme: DefaultScheme,
decoder: &DefaultDecoder{},
healthcheckEnabled: DefaultHealthcheckEnabled,
healthcheckTimeoutStartup: DefaultHealthcheckTimeoutStartup,
healthcheckTimeout: DefaultHealthcheckTimeout,
healthcheckInterval: DefaultHealthcheckInterval,
healthcheckStop: make(chan bool),
snifferEnabled: DefaultSnifferEnabled,
snifferTimeoutStartup: DefaultSnifferTimeoutStartup,
snifferTimeout: DefaultSnifferTimeout,
snifferInterval: DefaultSnifferInterval,
snifferCallback: nopSnifferCallback,
snifferStop: make(chan bool),
sendGetBodyAs: DefaultSendGetBodyAs,
gzipEnabled: DefaultGzipEnabled,
retrier: noRetries, // no retries by default
deprecationlog: noDeprecationLog,
}
// Run the options on it
for _, option := range options {
if err := option(c); err != nil {
return nil, err
}
}
// Use a default URL and normalize them
if len(c.urls) == 0 {
c.urls = []string{DefaultURL}
}
c.urls = canonicalize(c.urls...)
// If the URLs have auth info, use them here as an alternative to SetBasicAuth
if !c.basicAuth {
for _, urlStr := range c.urls {
u, err := url.Parse(urlStr)
if err == nil && u.User != nil {
c.basicAuth = true
c.basicAuthUsername = u.User.Username()
c.basicAuthPassword, _ = u.User.Password()
break
}
}
}
// Check if we can make a request to any of the specified URLs
if c.healthcheckEnabled {
if err := c.startupHealthcheck(c.healthcheckTimeoutStartup); err != nil {
return nil, err
}
}
if c.snifferEnabled {
// Sniff the cluster initially
if err := c.sniff(c.snifferTimeoutStartup); err != nil {
return nil, err
}
} else {
// Do not sniff the cluster initially. Use the provided URLs instead.
for _, url := range c.urls {
c.conns = append(c.conns, newConn(url, url))
}
}
if c.healthcheckEnabled {
// Perform an initial health check
c.healthcheck(c.healthcheckTimeoutStartup, true)
}
// Ensure that we have at least one connection available
if err := c.mustActiveConn(); err != nil {
return nil, err
}
// Check the required plugins
for _, plugin := range c.requiredPlugins {
found, err := c.HasPlugin(plugin)
if err != nil {
return nil, err
}
if !found {
return nil, fmt.Errorf("elastic: plugin %s not found", plugin)
}
}
if c.snifferEnabled {
go c.sniffer() // periodically update cluster information
}
if c.healthcheckEnabled {
go c.healthchecker() // start goroutine periodically ping all nodes of the cluster
}
c.mu.Lock()
c.running = true
c.mu.Unlock()
return c, nil
}
// NewClientFromConfig initializes a client from a configuration.
func NewClientFromConfig(cfg *config.Config) (*Client, error) {
var options []ClientOptionFunc
if cfg != nil {
if cfg.URL != "" {
options = append(options, SetURL(cfg.URL))
}
if cfg.Errorlog != "" {
f, err := os.OpenFile(cfg.Errorlog, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
if err != nil {
return nil, errors.Wrap(err, "unable to initialize error log")
}
l := log.New(f, "", 0)
options = append(options, SetErrorLog(l))
}
if cfg.Tracelog != "" {
f, err := os.OpenFile(cfg.Tracelog, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
if err != nil {
return nil, errors.Wrap(err, "unable to initialize trace log")
}
l := log.New(f, "", 0)
options = append(options, SetTraceLog(l))
}
if cfg.Infolog != "" {
f, err := os.OpenFile(cfg.Infolog, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
if err != nil {
return nil, errors.Wrap(err, "unable to initialize info log")
}
l := log.New(f, "", 0)
options = append(options, SetInfoLog(l))
}
if cfg.Username != "" || cfg.Password != "" {
options = append(options, SetBasicAuth(cfg.Username, cfg.Password))
}
if cfg.Sniff != nil {
options = append(options, SetSniff(*cfg.Sniff))
}
if cfg.Healthcheck != nil {
options = append(options, SetHealthcheck(*cfg.Healthcheck))
}
}
return NewClient(options...)
}
// NewSimpleClient creates a new short-lived Client that can be used in
// use cases where you need e.g. one client per request.
//
// While NewClient by default sets up e.g. periodic health checks
// and sniffing for new nodes in separate goroutines, NewSimpleClient does
// not and is meant as a simple replacement where you don't need all the
// heavy lifting of NewClient.
//
// NewSimpleClient does the following by default: First, all health checks
// are disabled, including timeouts and periodic checks. Second, sniffing
// is disabled, including timeouts and periodic checks. The number of retries
// is set to 1. NewSimpleClient also does not start any goroutines.
//
// Notice that you can still override settings by passing additional options,
// just like with NewClient.
func NewSimpleClient(options ...ClientOptionFunc) (*Client, error) {
c := &Client{
c: http.DefaultClient,
conns: make([]*conn, 0),
cindex: -1,
scheme: DefaultScheme,
decoder: &DefaultDecoder{},
healthcheckEnabled: false,
healthcheckTimeoutStartup: off,
healthcheckTimeout: off,
healthcheckInterval: off,
healthcheckStop: make(chan bool),
snifferEnabled: false,
snifferTimeoutStartup: off,
snifferTimeout: off,
snifferInterval: off,
snifferCallback: nopSnifferCallback,
snifferStop: make(chan bool),
sendGetBodyAs: DefaultSendGetBodyAs,
gzipEnabled: DefaultGzipEnabled,
retrier: noRetries, // no retries by default
deprecationlog: noDeprecationLog,
}
// Run the options on it
for _, option := range options {
if err := option(c); err != nil {
return nil, err
}
}
// Use a default URL and normalize them
if len(c.urls) == 0 {
c.urls = []string{DefaultURL}
}
c.urls = canonicalize(c.urls...)
// If the URLs have auth info, use them here as an alternative to SetBasicAuth
if !c.basicAuth {
for _, urlStr := range c.urls {
u, err := url.Parse(urlStr)
if err == nil && u.User != nil {
c.basicAuth = true
c.basicAuthUsername = u.User.Username()
c.basicAuthPassword, _ = u.User.Password()
break
}
}
}
for _, url := range c.urls {
c.conns = append(c.conns, newConn(url, url))
}
// Ensure that we have at least one connection available
if err := c.mustActiveConn(); err != nil {
return nil, err
}
// Check the required plugins
for _, plugin := range c.requiredPlugins {
found, err := c.HasPlugin(plugin)
if err != nil {
return nil, err
}
if !found {
return nil, fmt.Errorf("elastic: plugin %s not found", plugin)
}
}
c.mu.Lock()
c.running = true
c.mu.Unlock()
return c, nil
}
// SetHttpClient can be used to specify the http.Client to use when making
// HTTP requests to Elasticsearch.
func SetHttpClient(httpClient *http.Client) ClientOptionFunc {
return func(c *Client) error {
if httpClient != nil {
c.c = httpClient
} else {
c.c = http.DefaultClient
}
return nil
}
}
// SetBasicAuth can be used to specify the HTTP Basic Auth credentials to
// use when making HTTP requests to Elasticsearch.
func SetBasicAuth(username, password string) ClientOptionFunc {
return func(c *Client) error {
c.basicAuthUsername = username
c.basicAuthPassword = password
c.basicAuth = c.basicAuthUsername != "" || c.basicAuthPassword != ""
return nil
}
}
// SetURL defines the URL endpoints of the Elasticsearch nodes. Notice that
// when sniffing is enabled, these URLs are used to initially sniff the
// cluster on startup.
func SetURL(urls ...string) ClientOptionFunc {
return func(c *Client) error {
switch len(urls) {
case 0:
c.urls = []string{DefaultURL}
default:
c.urls = urls
}
return nil
}
}
// SetScheme sets the HTTP scheme to look for when sniffing (http or https).
// This is http by default.
func SetScheme(scheme string) ClientOptionFunc {
return func(c *Client) error {
c.scheme = scheme
return nil
}
}
// SetSniff enables or disables the sniffer (enabled by default).
func SetSniff(enabled bool) ClientOptionFunc {
return func(c *Client) error {
c.snifferEnabled = enabled
return nil
}
}
// SetSnifferTimeoutStartup sets the timeout for the sniffer that is used
// when creating a new client. The default is 5 seconds. Notice that the
// timeout being used for subsequent sniffing processes is set with
// SetSnifferTimeout.
func SetSnifferTimeoutStartup(timeout time.Duration) ClientOptionFunc {
return func(c *Client) error {
c.snifferTimeoutStartup = timeout
return nil
}
}
// SetSnifferTimeout sets the timeout for the sniffer that finds the
// nodes in a cluster. The default is 2 seconds. Notice that the timeout
// used when creating a new client on startup is usually greater and can
// be set with SetSnifferTimeoutStartup.
func SetSnifferTimeout(timeout time.Duration) ClientOptionFunc {
return func(c *Client) error {
c.snifferTimeout = timeout
return nil
}
}
// SetSnifferInterval sets the interval between two sniffing processes.
// The default interval is 15 minutes.
func SetSnifferInterval(interval time.Duration) ClientOptionFunc {
return func(c *Client) error {
c.snifferInterval = interval
return nil
}
}
// SnifferCallback defines the protocol for sniffing decisions.
type SnifferCallback func(*NodesInfoNode) bool
// nopSnifferCallback is the default sniffer callback: It accepts
// all nodes the sniffer finds.
var nopSnifferCallback = func(*NodesInfoNode) bool { return true }
// SetSnifferCallback allows the caller to modify sniffer decisions.
// When setting the callback, the given SnifferCallback is called for
// each (healthy) node found during the sniffing process.
// If the callback returns false, the node is ignored: No requests
// are routed to it.
func SetSnifferCallback(f SnifferCallback) ClientOptionFunc {
return func(c *Client) error {
if f != nil {
c.snifferCallback = f
}
return nil
}
}
// SetHealthcheck enables or disables healthchecks (enabled by default).
func SetHealthcheck(enabled bool) ClientOptionFunc {
return func(c *Client) error {
c.healthcheckEnabled = enabled
return nil
}
}
// SetHealthcheckTimeoutStartup sets the timeout for the initial health check.
// The default timeout is 5 seconds (see DefaultHealthcheckTimeoutStartup).
// Notice that timeouts for subsequent health checks can be modified with
// SetHealthcheckTimeout.
func SetHealthcheckTimeoutStartup(timeout time.Duration) ClientOptionFunc {
return func(c *Client) error {
c.healthcheckTimeoutStartup = timeout
return nil
}
}
// SetHealthcheckTimeout sets the timeout for periodic health checks.
// The default timeout is 1 second (see DefaultHealthcheckTimeout).
// Notice that a different (usually larger) timeout is used for the initial
// healthcheck, which is initiated while creating a new client.
// The startup timeout can be modified with SetHealthcheckTimeoutStartup.
func SetHealthcheckTimeout(timeout time.Duration) ClientOptionFunc {
return func(c *Client) error {
c.healthcheckTimeout = timeout
return nil
}
}
// SetHealthcheckInterval sets the interval between two health checks.
// The default interval is 60 seconds.
func SetHealthcheckInterval(interval time.Duration) ClientOptionFunc {
return func(c *Client) error {
c.healthcheckInterval = interval
return nil
}
}
// SetMaxRetries sets the maximum number of retries before giving up when
// performing a HTTP request to Elasticsearch.
//
// Deprecated: Replace with a Retry implementation.
func SetMaxRetries(maxRetries int) ClientOptionFunc {
return func(c *Client) error {
if maxRetries < 0 {
return errors.New("MaxRetries must be greater than or equal to 0")
} else if maxRetries == 0 {
c.retrier = noRetries
} else {
// Create a Retrier that will wait for 100ms (+/- jitter) between requests.
// This resembles the old behavior with maxRetries.
ticks := make([]int, maxRetries)
for i := 0; i < len(ticks); i++ {
ticks[i] = 100
}
backoff := NewSimpleBackoff(ticks...)
c.retrier = NewBackoffRetrier(backoff)
}
return nil
}
}
// SetGzip enables or disables gzip compression (disabled by default).
func SetGzip(enabled bool) ClientOptionFunc {
return func(c *Client) error {
c.gzipEnabled = enabled
return nil
}
}
// SetDecoder sets the Decoder to use when decoding data from Elasticsearch.
// DefaultDecoder is used by default.
func SetDecoder(decoder Decoder) ClientOptionFunc {
return func(c *Client) error {
if decoder != nil {
c.decoder = decoder
} else {
c.decoder = &DefaultDecoder{}
}
return nil
}
}
// SetRequiredPlugins can be used to indicate that some plugins are required
// before a Client will be created.
func SetRequiredPlugins(plugins ...string) ClientOptionFunc {
return func(c *Client) error {
if c.requiredPlugins == nil {
c.requiredPlugins = make([]string, 0)
}
c.requiredPlugins = append(c.requiredPlugins, plugins...)
return nil
}
}
// SetErrorLog sets the logger for critical messages like nodes joining
// or leaving the cluster or failing requests. It is nil by default.
func SetErrorLog(logger Logger) ClientOptionFunc {
return func(c *Client) error {
c.errorlog = logger
return nil
}
}
// SetInfoLog sets the logger for informational messages, e.g. requests
// and their response times. It is nil by default.
func SetInfoLog(logger Logger) ClientOptionFunc {
return func(c *Client) error {
c.infolog = logger
return nil
}
}
// SetTraceLog specifies the log.Logger to use for output of HTTP requests
// and responses which is helpful during debugging. It is nil by default.
func SetTraceLog(logger Logger) ClientOptionFunc {
return func(c *Client) error {
c.tracelog = logger
return nil
}
}
// SetSendGetBodyAs specifies the HTTP method to use when sending a GET request
// with a body. It is GET by default.
func SetSendGetBodyAs(httpMethod string) ClientOptionFunc {
return func(c *Client) error {
c.sendGetBodyAs = httpMethod
return nil
}
}
// SetRetrier specifies the retry strategy that handles errors during
// HTTP request/response with Elasticsearch.
func SetRetrier(retrier Retrier) ClientOptionFunc {
return func(c *Client) error {
if retrier == nil {
retrier = noRetries // no retries by default
}
c.retrier = retrier
return nil
}
}
// SetHeaders adds a list of default HTTP headers that will be added to
// each requests executed by PerformRequest.
func SetHeaders(headers http.Header) ClientOptionFunc {
return func(c *Client) error {
c.headers = headers
return nil
}
}
// String returns a string representation of the client status.
func (c *Client) String() string {
c.connsMu.Lock()
conns := c.conns
c.connsMu.Unlock()
var buf bytes.Buffer
for i, conn := range conns {
if i > 0 {
buf.WriteString(", ")
}
buf.WriteString(conn.String())
}
return buf.String()
}
// IsRunning returns true if the background processes of the client are
// running, false otherwise.
func (c *Client) IsRunning() bool {
c.mu.RLock()
defer c.mu.RUnlock()
return c.running
}
// Start starts the background processes like sniffing the cluster and
// periodic health checks. You don't need to run Start when creating a
// client with NewClient; the background processes are run by default.
//
// If the background processes are already running, this is a no-op.
func (c *Client) Start() {
c.mu.RLock()
if c.running {
c.mu.RUnlock()
return
}
c.mu.RUnlock()
if c.snifferEnabled {
go c.sniffer()
}
if c.healthcheckEnabled {
go c.healthchecker()
}
c.mu.Lock()
c.running = true
c.mu.Unlock()
c.infof("elastic: client started")
}
// Stop stops the background processes that the client is running,
// i.e. sniffing the cluster periodically and running health checks
// on the nodes.
//
// If the background processes are not running, this is a no-op.
func (c *Client) Stop() {
c.mu.RLock()
if !c.running {
c.mu.RUnlock()
return
}
c.mu.RUnlock()
if c.healthcheckEnabled {
c.healthcheckStop <- true
<-c.healthcheckStop
}
if c.snifferEnabled {
c.snifferStop <- true
<-c.snifferStop
}
c.mu.Lock()
c.running = false
c.mu.Unlock()
c.infof("elastic: client stopped")
}
// errorf logs to the error log.
func (c *Client) errorf(format string, args ...interface{}) {
if c.errorlog != nil {
c.errorlog.Printf(format, args...)
}
}
// infof logs informational messages.
func (c *Client) infof(format string, args ...interface{}) {
if c.infolog != nil {
c.infolog.Printf(format, args...)
}
}
// tracef logs to the trace log.
func (c *Client) tracef(format string, args ...interface{}) {
if c.tracelog != nil {
c.tracelog.Printf(format, args...)
}
}
// dumpRequest dumps the given HTTP request to the trace log.
func (c *Client) dumpRequest(r *http.Request) {
if c.tracelog != nil {
out, err := httputil.DumpRequestOut(r, true)
if err == nil {
c.tracef("%s\n", string(out))
}
}
}
// dumpResponse dumps the given HTTP response to the trace log.
func (c *Client) dumpResponse(resp *http.Response) {
if c.tracelog != nil {
out, err := httputil.DumpResponse(resp, true)
if err == nil {
c.tracef("%s\n", string(out))
}
}
}
// sniffer periodically runs sniff.
func (c *Client) sniffer() {
c.mu.RLock()
timeout := c.snifferTimeout
interval := c.snifferInterval
c.mu.RUnlock()
ticker := time.NewTicker(interval)
defer ticker.Stop()
for {
select {
case <-c.snifferStop:
// we are asked to stop, so we signal back that we're stopping now
c.snifferStop <- true
return
case <-ticker.C:
c.sniff(timeout)
}
}
}
// sniff uses the Node Info API to return the list of nodes in the cluster.
// It uses the list of URLs passed on startup plus the list of URLs found
// by the preceding sniffing process (if sniffing is enabled).
//
// If sniffing is disabled, this is a no-op.
func (c *Client) sniff(timeout time.Duration) error {
c.mu.RLock()
if !c.snifferEnabled {
c.mu.RUnlock()
return nil
}
// Use all available URLs provided to sniff the cluster.
var urls []string
urlsMap := make(map[string]bool)
// Add all URLs provided on startup
for _, url := range c.urls {
urlsMap[url] = true
urls = append(urls, url)
}
c.mu.RUnlock()
// Add all URLs found by sniffing
c.connsMu.RLock()
for _, conn := range c.conns {
if !conn.IsDead() {
url := conn.URL()
if _, found := urlsMap[url]; !found {
urls = append(urls, url)
}
}
}
c.connsMu.RUnlock()
if len(urls) == 0 {
return errors.Wrap(ErrNoClient, "no URLs found")
}
// Start sniffing on all found URLs
ch := make(chan []*conn, len(urls))
ctx, cancel := context.WithTimeout(context.Background(), timeout)
defer cancel()
for _, url := range urls {
go func(url string) { ch <- c.sniffNode(ctx, url) }(url)
}
// Wait for the results to come back, or the process times out.
for {
select {
case conns := <-ch:
if len(conns) > 0 {
c.updateConns(conns)
return nil
}
case <-ctx.Done():
// We get here if no cluster responds in time
return errors.Wrap(ErrNoClient, "sniff timeout")
}
}
}
// sniffNode sniffs a single node. This method is run as a goroutine
// in sniff. If successful, it returns the list of node URLs extracted
// from the result of calling Nodes Info API. Otherwise, an empty array
// is returned.
func (c *Client) sniffNode(ctx context.Context, url string) []*conn {
var nodes []*conn
// Call the Nodes Info API at /_nodes/http
req, err := NewRequest("GET", url+"/_nodes/http")
if err != nil {
return nodes
}
c.mu.RLock()
if c.basicAuth {
req.SetBasicAuth(c.basicAuthUsername, c.basicAuthPassword)
}
c.mu.RUnlock()
res, err := c.c.Do((*http.Request)(req).WithContext(ctx))
if err != nil {
return nodes
}
if res == nil {
return nodes
}
if res.Body != nil {
defer res.Body.Close()
}
var info NodesInfoResponse
if err := json.NewDecoder(res.Body).Decode(&info); err == nil {
if len(info.Nodes) > 0 {
for nodeID, node := range info.Nodes {
if c.snifferCallback(node) {
if node.HTTP != nil && len(node.HTTP.PublishAddress) > 0 {
url := c.extractHostname(c.scheme, node.HTTP.PublishAddress)
if url != "" {
nodes = append(nodes, newConn(nodeID, url))
}
}
}
}
}
}
return nodes
}
// reSniffHostAndPort is used to extract hostname and port from a result
// from a Nodes Info API (example: "inet[/127.0.0.1:9200]").
var reSniffHostAndPort = regexp.MustCompile(`\/([^:]*):([0-9]+)\]`)
func (c *Client) extractHostname(scheme, address string) string {
if strings.HasPrefix(address, "inet") {
m := reSniffHostAndPort.FindStringSubmatch(address)
if len(m) == 3 {
return fmt.Sprintf("%s://%s:%s", scheme, m[1], m[2])
}
}
s := address
if idx := strings.Index(s, "/"); idx >= 0 {
s = s[idx+1:]
}
if strings.Index(s, ":") < 0 {
return ""
}
return fmt.Sprintf("%s://%s", scheme, s)
}
// updateConns updates the clients' connections with new information
// gather by a sniff operation.
func (c *Client) updateConns(conns []*conn) {
c.connsMu.Lock()
// Build up new connections:
// If we find an existing connection, use that (including no. of failures etc.).
// If we find a new connection, add it.
var newConns []*conn
for _, conn := range conns {
var found bool
for _, oldConn := range c.conns {
if oldConn.NodeID() == conn.NodeID() {
// Take over the old connection
newConns = append(newConns, oldConn)
found = true
break
}
}
if !found {
// New connection didn't exist, so add it to our list of new conns.
c.infof("elastic: %s joined the cluster", conn.URL())
newConns = append(newConns, conn)
}