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An example of the current way to add additional context to k8s workqueue metrics using OpenTelemetry.
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| package main | |
| import ( | |
| "context" | |
| "go.opentelemetry.io/otel/attribute" | |
| "go.opentelemetry.io/otel/metric" | |
| "go.opentelemetry.io/otel/metric/instrument" | |
| "go.opentelemetry.io/otel/metric/instrument/syncint64" | |
| "k8s.io/client-go/util/workqueue" | |
| "strings" | |
| "time" | |
| ) | |
| func main() { | |
| provider := &customMetricsProvider{ | |
| meter: metric.NewNoopMeterProvider().Meter("workqueue"), | |
| } | |
| workqueue.SetProvider(provider) | |
| // Queue name must encode all context for the queue, | |
| // as that is the only state passed to the global metrics provider. | |
| // Let's say name is in the format "%s-{key:val};*" | |
| queue := workqueue.NewNamed("test-org:austince;project:test2") | |
| go func() { | |
| for i := 1; ; i++ { | |
| queue.Add(i) | |
| time.Sleep(time.Second) | |
| } | |
| }() | |
| <-context.Background().Done() | |
| } | |
| // customMetricsProvider adds additional identifying context to workqueue metrics | |
| // by parsing the queue name and delegating to an OpenTelemetry meter. | |
| type customMetricsProvider struct { | |
| meter metric.Meter | |
| } | |
| var _ workqueue.MetricsProvider = &customMetricsProvider{} | |
| func (d *customMetricsProvider) NewDepthMetric(name string) workqueue.GaugeMetric { | |
| // In the format "%s-{key:val};*" | |
| // Would also need to handle if this is called from a library and doesn't have the same structure. | |
| parts := strings.SplitN(name, "-", 2) | |
| name = parts[0] | |
| var attrs []attribute.KeyValue | |
| keyVals := strings.Split(parts[1], ";") | |
| for _, p := range keyVals { | |
| keyParts := strings.SplitN(p, ":", 2) | |
| attrs = append(attrs, attribute.KeyValue{ | |
| Key: attribute.Key(keyParts[0]), | |
| // Can't easily support other value types besides strings | |
| Value: attribute.StringValue(keyParts[1]), | |
| }) | |
| } | |
| counter, err := d.meter.SyncInt64(). | |
| UpDownCounter(name, instrument.WithDescription("Current depth of workqueue")) | |
| if err != nil { | |
| panic(err) | |
| } | |
| return &otelGauge{ | |
| counter: counter, | |
| extraAttributes: attrs, | |
| } | |
| } | |
| func (d *customMetricsProvider) NewAddsMetric(name string) workqueue.CounterMetric { | |
| return &noOpMetrics{} | |
| } | |
| func (d *customMetricsProvider) NewLatencyMetric(name string) workqueue.HistogramMetric { | |
| return &noOpMetrics{} | |
| } | |
| func (d *customMetricsProvider) NewWorkDurationMetric(name string) workqueue.HistogramMetric { | |
| return &noOpMetrics{} | |
| } | |
| func (d *customMetricsProvider) NewUnfinishedWorkSecondsMetric(name string) workqueue.SettableGaugeMetric { | |
| return &noOpMetrics{} | |
| } | |
| func (d *customMetricsProvider) NewLongestRunningProcessorSecondsMetric(name string) workqueue.SettableGaugeMetric { | |
| return &noOpMetrics{} | |
| } | |
| func (d *customMetricsProvider) NewRetriesMetric(name string) workqueue.CounterMetric { | |
| return &noOpMetrics{} | |
| } | |
| // noOpMetrics is a no-op implementation of all workqueue metrics. | |
| type noOpMetrics struct{} | |
| var _ workqueue.GaugeMetric = &noOpMetrics{} | |
| func (n *noOpMetrics) Dec() { | |
| } | |
| var _ workqueue.CounterMetric = &noOpMetrics{} | |
| func (n *noOpMetrics) Inc() {} | |
| var _ workqueue.SettableGaugeMetric = &noOpMetrics{} | |
| func (n *noOpMetrics) Set(f float64) {} | |
| var _ workqueue.HistogramMetric = &noOpMetrics{} | |
| func (n *noOpMetrics) Observe(f float64) { | |
| } | |
| // otelGauge implements workqueue.GaugeMetric using OpenTelemetry. | |
| type otelGauge struct { | |
| counter syncint64.UpDownCounter | |
| extraAttributes []attribute.KeyValue | |
| } | |
| func (o *otelGauge) Inc() { | |
| o.counter.Add(context.Background(), 1, o.extraAttributes...) | |
| } | |
| func (o *otelGauge) Dec() { | |
| o.counter.Add(context.Background(), -1, o.extraAttributes...) | |
| } | |
| var _ workqueue.GaugeMetric = &otelGauge{} |
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