forked from grafana/loki
/
target_syncer.go
321 lines (294 loc) · 8.81 KB
/
target_syncer.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
package kafka
import (
"context"
"errors"
"fmt"
"sync"
"time"
"github.com/Shopify/sarama"
"github.com/go-kit/log"
"github.com/go-kit/log/level"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/model"
"github.com/prometheus/prometheus/model/labels"
"github.com/frelon/loki/v2/clients/pkg/logentry/stages"
"github.com/frelon/loki/v2/clients/pkg/promtail/api"
"github.com/frelon/loki/v2/clients/pkg/promtail/scrapeconfig"
"github.com/frelon/loki/v2/clients/pkg/promtail/targets/target"
"github.com/frelon/loki/v2/pkg/util"
)
var TopicPollInterval = 30 * time.Second
type TopicManager interface {
Topics() ([]string, error)
}
type TargetSyncer struct {
logger log.Logger
cfg scrapeconfig.Config
pipeline *stages.Pipeline
reg prometheus.Registerer
client api.EntryHandler
topicManager TopicManager
consumer
close func() error
ctx context.Context
cancel context.CancelFunc
wg sync.WaitGroup
previousTopics []string
}
func NewSyncer(
reg prometheus.Registerer,
logger log.Logger,
cfg scrapeconfig.Config,
pushClient api.EntryHandler,
) (*TargetSyncer, error) {
if err := validateConfig(&cfg); err != nil {
return nil, err
}
version, err := sarama.ParseKafkaVersion(cfg.KafkaConfig.Version)
if err != nil {
return nil, err
}
config := sarama.NewConfig()
config.Version = version
config.Consumer.Offsets.Initial = sarama.OffsetOldest
switch cfg.KafkaConfig.Assignor {
case sarama.StickyBalanceStrategyName:
config.Consumer.Group.Rebalance.Strategy = sarama.BalanceStrategySticky
case sarama.RoundRobinBalanceStrategyName:
config.Consumer.Group.Rebalance.Strategy = sarama.BalanceStrategyRoundRobin
case sarama.RangeBalanceStrategyName, "":
config.Consumer.Group.Rebalance.Strategy = sarama.BalanceStrategyRange
default:
return nil, fmt.Errorf("unrecognized consumer group partition assignor: %s", cfg.KafkaConfig.Assignor)
}
config, err = withAuthentication(*config, cfg.KafkaConfig.Authentication)
if err != nil {
return nil, fmt.Errorf("error setting up kafka authentication: %w", err)
}
client, err := sarama.NewClient(cfg.KafkaConfig.Brokers, config)
if err != nil {
return nil, fmt.Errorf("error creating kafka client: %w", err)
}
group, err := sarama.NewConsumerGroup(cfg.KafkaConfig.Brokers, cfg.KafkaConfig.GroupID, config)
if err != nil {
return nil, fmt.Errorf("error creating consumer group client: %w", err)
}
topicManager, err := newTopicManager(client, cfg.KafkaConfig.Topics)
if err != nil {
return nil, fmt.Errorf("error creating topic manager: %w", err)
}
pipeline, err := stages.NewPipeline(log.With(logger, "component", "kafka_pipeline"), cfg.PipelineStages, &cfg.JobName, reg)
if err != nil {
return nil, fmt.Errorf("error creating pipeline: %w", err)
}
ctx, cancel := context.WithCancel(context.Background())
t := &TargetSyncer{
logger: logger,
ctx: ctx,
cancel: cancel,
topicManager: topicManager,
cfg: cfg,
reg: reg,
client: pushClient,
pipeline: pipeline,
close: func() error {
if err := group.Close(); err != nil {
level.Warn(logger).Log("msg", "error while closing consumer group", "err", err)
}
return client.Close()
},
consumer: consumer{
ctx: context.Background(),
cancel: func() {},
ConsumerGroup: group,
logger: logger,
},
}
t.discoverer = t
t.loop()
return t, nil
}
func withAuthentication(cfg sarama.Config, authCfg scrapeconfig.KafkaAuthentication) (*sarama.Config, error) {
if len(authCfg.Type) == 0 || authCfg.Type == scrapeconfig.KafkaAuthenticationTypeNone {
return &cfg, nil
}
switch authCfg.Type {
case scrapeconfig.KafkaAuthenticationTypeSSL:
return withSSLAuthentication(cfg, authCfg)
case scrapeconfig.KafkaAuthenticationTypeSASL:
return withSASLAuthentication(cfg, authCfg)
default:
return nil, fmt.Errorf("unsupported authentication type %s", authCfg.Type)
}
}
func withSSLAuthentication(cfg sarama.Config, authCfg scrapeconfig.KafkaAuthentication) (*sarama.Config, error) {
cfg.Net.TLS.Enable = true
tc, err := createTLSConfig(authCfg.TLSConfig)
if err != nil {
return nil, err
}
cfg.Net.TLS.Config = tc
return &cfg, nil
}
func withSASLAuthentication(cfg sarama.Config, authCfg scrapeconfig.KafkaAuthentication) (*sarama.Config, error) {
cfg.Net.SASL.Enable = true
cfg.Net.SASL.User = authCfg.SASLConfig.User
cfg.Net.SASL.Password = authCfg.SASLConfig.Password.Value
cfg.Net.SASL.Mechanism = authCfg.SASLConfig.Mechanism
if cfg.Net.SASL.Mechanism == "" {
cfg.Net.SASL.Mechanism = sarama.SASLTypePlaintext
}
supportedMechanism := []string{
sarama.SASLTypeSCRAMSHA512,
sarama.SASLTypeSCRAMSHA256,
sarama.SASLTypePlaintext,
}
if !util.StringsContain(supportedMechanism, string(authCfg.SASLConfig.Mechanism)) {
return nil, fmt.Errorf("error unsupported sasl mechanism: %s", authCfg.SASLConfig.Mechanism)
}
if cfg.Net.SASL.Mechanism == sarama.SASLTypeSCRAMSHA512 {
cfg.Net.SASL.SCRAMClientGeneratorFunc = func() sarama.SCRAMClient {
return &XDGSCRAMClient{
HashGeneratorFcn: SHA512,
}
}
}
if cfg.Net.SASL.Mechanism == sarama.SASLTypeSCRAMSHA256 {
cfg.Net.SASL.SCRAMClientGeneratorFunc = func() sarama.SCRAMClient {
return &XDGSCRAMClient{
HashGeneratorFcn: SHA256,
}
}
}
if authCfg.SASLConfig.UseTLS {
tc, err := createTLSConfig(authCfg.SASLConfig.TLSConfig)
if err != nil {
return nil, err
}
cfg.Net.TLS.Config = tc
cfg.Net.TLS.Enable = true
}
return &cfg, nil
}
func (ts *TargetSyncer) loop() {
topicChanged := make(chan []string)
ts.wg.Add(2)
go func() {
defer ts.wg.Done()
for {
select {
case <-ts.ctx.Done():
return
case topics := <-topicChanged:
level.Info(ts.logger).Log("msg", "new topics received", "topics", fmt.Sprintf("%+v", topics))
ts.stop()
if len(topics) > 0 { // no topics we don't need to start.
ts.start(ts.ctx, topics)
}
}
}
}()
go func() {
defer ts.wg.Done()
ticker := time.NewTicker(TopicPollInterval)
defer ticker.Stop()
tick := func() {
select {
case <-ts.ctx.Done():
case <-ticker.C:
}
}
for ; true; tick() { // instant tick.
if ts.ctx.Err() != nil {
ts.stop()
close(topicChanged)
return
}
newTopics, ok, err := ts.fetchTopics()
if err != nil {
level.Warn(ts.logger).Log("msg", "failed to fetch topics", "err", err)
continue
}
if ok {
topicChanged <- newTopics
}
}
}()
}
// fetchTopics fetches and return new topics, if there's a difference with previous found topics
// it will return true as second return value.
func (ts *TargetSyncer) fetchTopics() ([]string, bool, error) {
new, err := ts.topicManager.Topics()
if err != nil {
return nil, false, err
}
if len(ts.previousTopics) != len(new) {
ts.previousTopics = new
return new, true, nil
}
for i, v := range ts.previousTopics {
if v != new[i] {
ts.previousTopics = new
return new, true, nil
}
}
return nil, false, nil
}
func (ts *TargetSyncer) Stop() error {
ts.cancel()
ts.wg.Wait()
return ts.close()
}
// NewTarget creates a new targets based on the current kafka claim and group session.
func (ts *TargetSyncer) NewTarget(session sarama.ConsumerGroupSession, claim sarama.ConsumerGroupClaim) (RunnableTarget, error) {
discoveredLabels := model.LabelSet{
"__meta_kafka_topic": model.LabelValue(claim.Topic()),
"__meta_kafka_partition": model.LabelValue(fmt.Sprintf("%d", claim.Partition())),
"__meta_kafka_member_id": model.LabelValue(session.MemberID()),
"__meta_kafka_group_id": model.LabelValue(ts.cfg.KafkaConfig.GroupID),
}
details := newDetails(session, claim)
labelMap := make(map[string]string)
for k, v := range discoveredLabels.Clone().Merge(ts.cfg.KafkaConfig.Labels) {
labelMap[string(k)] = string(v)
}
labelOut := format(labels.FromMap(labelMap), ts.cfg.RelabelConfigs)
if len(labelOut) == 0 {
level.Warn(ts.logger).Log("msg", "dropping target", "reason", "no labels", "details", details, "discovered_labels", discoveredLabels.String())
return &runnableDroppedTarget{
Target: target.NewDroppedTarget("dropping target, no labels", discoveredLabels),
runFn: func() {
for range claim.Messages() {
}
},
}, nil
}
t := NewTarget(
session,
claim,
discoveredLabels,
labelOut,
ts.cfg.RelabelConfigs,
ts.pipeline.Wrap(ts.client),
ts.cfg.KafkaConfig.UseIncomingTimestamp,
)
return t, nil
}
func validateConfig(cfg *scrapeconfig.Config) error {
if cfg.KafkaConfig == nil {
return errors.New("Kafka configuration is empty")
}
if cfg.KafkaConfig.Version == "" {
cfg.KafkaConfig.Version = "2.1.1"
}
if len(cfg.KafkaConfig.Brokers) == 0 {
return errors.New("no Kafka bootstrap brokers defined")
}
if len(cfg.KafkaConfig.Topics) == 0 {
return errors.New("no topics given to be consumed")
}
if cfg.KafkaConfig.GroupID == "" {
cfg.KafkaConfig.GroupID = "promtail"
}
return nil
}