/
extension.go
204 lines (175 loc) · 5.63 KB
/
extension.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
// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0
package healthcheckv2extension // import "github.com/open-telemetry/opentelemetry-collector-contrib/extension/healthcheckv2extension"
import (
"context"
"go.opentelemetry.io/collector/component"
"go.opentelemetry.io/collector/confmap"
"go.opentelemetry.io/collector/extension"
"go.uber.org/multierr"
"go.uber.org/zap"
"github.com/open-telemetry/opentelemetry-collector-contrib/extension/healthcheckv2extension/internal/grpc"
"github.com/open-telemetry/opentelemetry-collector-contrib/extension/healthcheckv2extension/internal/http"
"github.com/open-telemetry/opentelemetry-collector-contrib/extension/healthcheckv2extension/internal/status"
)
type eventSourcePair struct {
source *component.InstanceID
event *component.StatusEvent
}
type healthCheckExtension struct {
config Config
telemetry component.TelemetrySettings
aggregator *status.Aggregator
subcomponents []component.Component
eventCh chan *eventSourcePair
readyCh chan struct{}
}
var _ component.Component = (*healthCheckExtension)(nil)
var _ extension.ConfigWatcher = (*healthCheckExtension)(nil)
var _ extension.PipelineWatcher = (*healthCheckExtension)(nil)
func newExtension(
ctx context.Context,
config Config,
set extension.CreateSettings,
) *healthCheckExtension {
var comps []component.Component
errPriority := status.PriorityPermanent
if config.ComponentHealthConfig != nil &&
config.ComponentHealthConfig.IncludeRecoverable &&
!config.ComponentHealthConfig.IncludePermanent {
errPriority = status.PriorityRecoverable
}
aggregator := status.NewAggregator(errPriority)
if config.UseV2 && config.GRPCConfig != nil {
grpcServer := grpc.NewServer(
config.GRPCConfig,
config.ComponentHealthConfig,
set.TelemetrySettings,
aggregator,
)
comps = append(comps, grpcServer)
}
if !config.UseV2 || config.UseV2 && config.HTTPConfig != nil {
httpServer := http.NewServer(
config.HTTPConfig,
config.LegacyConfig,
config.ComponentHealthConfig,
set.TelemetrySettings,
aggregator,
)
comps = append(comps, httpServer)
}
hc := &healthCheckExtension{
config: config,
subcomponents: comps,
telemetry: set.TelemetrySettings,
aggregator: aggregator,
eventCh: make(chan *eventSourcePair),
readyCh: make(chan struct{}),
}
// Start processing events in the background so that our status watcher doesn't
// block others before the extension starts.
go hc.eventLoop(ctx)
return hc
}
// Start implements the component.Component interface.
func (hc *healthCheckExtension) Start(ctx context.Context, host component.Host) error {
hc.telemetry.Logger.Debug("Starting health check extension V2", zap.Any("config", hc.config))
for _, comp := range hc.subcomponents {
if err := comp.Start(ctx, host); err != nil {
return err
}
}
return nil
}
// Shutdown implements the component.Component interface.
func (hc *healthCheckExtension) Shutdown(ctx context.Context) error {
// Preemptively send the stopped event, so it can be exported before shutdown
hc.telemetry.ReportStatus(component.NewStatusEvent(component.StatusStopped))
close(hc.eventCh)
hc.aggregator.Close()
var err error
for _, comp := range hc.subcomponents {
err = multierr.Append(err, comp.Shutdown(ctx))
}
return err
}
// ComponentStatusChanged implements the extension.StatusWatcher interface.
func (hc *healthCheckExtension) ComponentStatusChanged(
source *component.InstanceID,
event *component.StatusEvent,
) {
// There can be late arriving events after shutdown. We need to close
// the event channel so that this function doesn't block and we release all
// goroutines, but attempting to write to a closed channel will panic; log
// and recover.
defer func() {
if r := recover(); r != nil {
hc.telemetry.Logger.Info(
"discarding event received after shutdown",
zap.Any("source", source),
zap.Any("event", event),
)
}
}()
hc.eventCh <- &eventSourcePair{source: source, event: event}
}
// NotifyConfig implements the extension.ConfigWatcher interface.
func (hc *healthCheckExtension) NotifyConfig(ctx context.Context, conf *confmap.Conf) error {
var err error
for _, comp := range hc.subcomponents {
if cw, ok := comp.(extension.ConfigWatcher); ok {
err = multierr.Append(err, cw.NotifyConfig(ctx, conf))
}
}
return err
}
// Ready implements the extension.PipelineWatcher interface.
func (hc *healthCheckExtension) Ready() error {
close(hc.readyCh)
return nil
}
// NotReady implements the extension.PipelineWatcher interface.
func (hc *healthCheckExtension) NotReady() error {
return nil
}
func (hc *healthCheckExtension) eventLoop(ctx context.Context) {
// Record events with component.StatusStarting, but queue other events until
// PipelineWatcher.Ready is called. This prevents aggregate statuses from
// flapping between StatusStarting and StatusOK as components are started
// individually by the service.
var eventQueue []*eventSourcePair
for loop := true; loop; {
select {
case esp, ok := <-hc.eventCh:
if !ok {
return
}
if esp.event.Status() != component.StatusStarting {
eventQueue = append(eventQueue, esp)
continue
}
hc.aggregator.RecordStatus(esp.source, esp.event)
case <-hc.readyCh:
for _, esp := range eventQueue {
hc.aggregator.RecordStatus(esp.source, esp.event)
}
eventQueue = nil
loop = false
case <-ctx.Done():
return
}
}
// After PipelineWatcher.Ready, record statuses as they are received.
for {
select {
case esp, ok := <-hc.eventCh:
if !ok {
return
}
hc.aggregator.RecordStatus(esp.source, esp.event)
case <-ctx.Done():
return
}
}
}