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Merged
openshift-merge-bot merged 3 commits into from
May 11, 2026
Merged

[release-v1.21] add missing labels to queue-proxy prometheus metrics #1751

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dbe9ac5
hack kn attibutes into queue-proxy prometheus metrics
maschmid Apr 23, 2026
61329f5
add k8s metrics
maschmid Apr 23, 2026
73e9f54
update go.mod
maschmid May 7, 2026
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4 changes: 2 additions & 2 deletions go.mod
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Original file line number Diff line number Diff line change
Expand Up @@ -14,10 +14,12 @@ require (
github.com/influxdata/influxdb-client-go/v2 v2.14.0
github.com/kelseyhightower/envconfig v1.4.0
github.com/prometheus/client_golang v1.23.2
github.com/prometheus/otlptranslator v1.0.0
github.com/tsenart/vegeta/v12 v12.13.0
go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.64.0
go.opentelemetry.io/contrib/instrumentation/runtime v0.64.0
go.opentelemetry.io/otel v1.39.0
go.opentelemetry.io/otel/exporters/prometheus v0.61.0
go.opentelemetry.io/otel/metric v1.39.0
go.opentelemetry.io/otel/sdk v1.39.0
go.opentelemetry.io/otel/sdk/metric v1.39.0
Expand Down Expand Up @@ -125,7 +127,6 @@ require (
github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
github.com/prometheus/client_model v0.6.2 // indirect
github.com/prometheus/common v0.67.4 // indirect
github.com/prometheus/otlptranslator v1.0.0 // indirect
github.com/prometheus/procfs v0.19.2 // indirect
github.com/rs/dnscache v0.0.0-20230804202142-fc85eb664529 // indirect
github.com/russross/blackfriday/v2 v2.1.0 // indirect
Expand All @@ -141,7 +142,6 @@ require (
go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.39.0 // indirect
go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.39.0 // indirect
go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.39.0 // indirect
go.opentelemetry.io/otel/exporters/prometheus v0.61.0 // indirect
go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.39.0 // indirect
go.opentelemetry.io/proto/otlp v1.9.0 // indirect
go.uber.org/multierr v1.11.0 // indirect
Expand Down
112 changes: 92 additions & 20 deletions pkg/queue/sharedmain/otel.go
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Original file line number Diff line number Diff line change
Expand Up @@ -19,54 +19,65 @@ package sharedmain
import (
"cmp"
"context"
"errors"
"fmt"
"net"
"os"

"github.com/prometheus/otlptranslator"
"go.opentelemetry.io/contrib/instrumentation/runtime"
"go.opentelemetry.io/otel"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/sdk/metric"
otelprom "go.opentelemetry.io/otel/exporters/prometheus"
otelmetric "go.opentelemetry.io/otel/metric"
sdkmetric "go.opentelemetry.io/otel/sdk/metric"
"go.opentelemetry.io/otel/sdk/resource"
"go.opentelemetry.io/otel/sdk/trace"
"go.uber.org/zap"

"knative.dev/pkg/changeset"
"knative.dev/pkg/observability/metrics"
promserver "knative.dev/pkg/observability/metrics/prometheus"
"knative.dev/pkg/observability/semconv"
"knative.dev/pkg/observability/tracing"
"knative.dev/pkg/system"
servingmetrics "knative.dev/serving/pkg/metrics"
"knative.dev/serving/pkg/networking"
)

// observabilityMeterProvider combines the OTel metric provider interface with a Shutdown method.
type observabilityMeterProvider interface {
otelmetric.MeterProvider
Shutdown(context.Context) error
}

func SetupObservabilityOrDie(
ctx context.Context,
cfg *config,
logger *zap.SugaredLogger,
) (*metrics.MeterProvider, *tracing.TracerProvider) {
) (observabilityMeterProvider, *tracing.TracerProvider) {
r := res(logger, cfg)

// Force the port to be the default queue user metrics port if it's not overridden
// by the operator
if cfg.Observability.RequestMetrics.Protocol == metrics.ProtocolPrometheus &&
cfg.Observability.RequestMetrics.Endpoint == "" {
cfg.Observability.RequestMetrics.Endpoint = fmt.Sprintf(":%d", networking.UserQueueMetricsPort)
}

meterProvider, err := metrics.NewMeterProvider(
ctx,
cfg.Observability.RequestMetrics,
metric.WithResource(r),
)
if err != nil {
logger.Fatalw("Failed to setup meter provider", zap.Error(err))
var mp observabilityMeterProvider
if cfg.Observability.RequestMetrics.Protocol == metrics.ProtocolPrometheus {
mp = buildPrometheusProvider(cfg, r, logger)
} else {
meterProvider, err := metrics.NewMeterProvider(
ctx,
cfg.Observability.RequestMetrics,
sdkmetric.WithResource(r),
)
if err != nil {
logger.Fatalw("Failed to setup meter provider", zap.Error(err))
}
mp = meterProvider
}

otel.SetMeterProvider(meterProvider)
otel.SetMeterProvider(mp)

err = runtime.Start(
err := runtime.Start(
runtime.WithMinimumReadMemStatsInterval(cfg.Observability.Runtime.ExportInterval),
runtime.WithMeterProvider(meterProvider),
runtime.WithMeterProvider(mp),
)
if err != nil {
logger.Fatalw("Failed to start runtime metrics", zap.Error(err))
Expand All @@ -84,7 +95,68 @@ func SetupObservabilityOrDie(
otel.SetTextMapPropagator(tracing.DefaultTextMapPropagator())
otel.SetTracerProvider(tracerProvider)

return meterProvider, tracerProvider
return mp, tracerProvider
}

// buildPrometheusProvider creates a Prometheus-backed meter provider that exposes
// the serving-specific resource attributes (service, configuration, revision) as
// constant Prometheus labels on every metric.
func buildPrometheusProvider(cfg *config, r *resource.Resource, logger *zap.SugaredLogger) observabilityMeterProvider {
endpoint := cfg.Observability.RequestMetrics.Endpoint
if endpoint == "" {
endpoint = fmt.Sprintf(":%d", networking.UserQueueMetricsPort)
}

reader, err := otelprom.New(
otelprom.WithTranslationStrategy(otlptranslator.UnderscoreEscapingWithSuffixes),
otelprom.WithResourceAsConstantLabels(attribute.NewAllowKeysFilter(
attribute.Key(servingmetrics.ServiceNameKey),
attribute.Key(servingmetrics.ConfigurationNameKey),
attribute.Key(servingmetrics.RevisionNameKey),
semconv.K8SNamespaceNameKey,
semconv.K8SPodNameKey,
)),
)
if err != nil {
logger.Fatalw("Failed to create prometheus exporter", zap.Error(err))
}

host, port, err := net.SplitHostPort(endpoint)
if err != nil {
logger.Fatalw("Invalid prometheus endpoint", zap.String("endpoint", endpoint), zap.Error(err))
}

server, err := promserver.NewServer(
promserver.WithHost(host),
promserver.WithPort(port),
)
if err != nil {
logger.Fatalw("Failed to create prometheus server", zap.Error(err))
}
go server.ListenAndServe()
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@linkvt linkvt May 6, 2026

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Claude reported that we should call Serve() here, see https://pkg.go.dev/knative.dev/pkg/observability/metrics/prometheus#Server.Serve

Looks good to me besides that

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@maschmid maschmid May 6, 2026

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The code is based on https://github.com/openshift-knative/serving/blob/release-v1.21/vendor/knative.dev/pkg/observability/metrics/prometheus_enabled.go (basically that with just the WithResourceAsConstantLabels config added), so we should probably try to keep the behavior as similar as possible.

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@maschmid maschmid May 6, 2026

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also, vendor/knative.dev/pkg/observability/metrics/prometheus/server.go does not expose Serve()


sdkProvider := sdkmetric.NewMeterProvider(
sdkmetric.WithReader(reader),
sdkmetric.WithResource(r),
)

return &prometheusProvider{
MeterProvider: sdkProvider,
shutdownFns: []func(context.Context) error{sdkProvider.Shutdown, server.Shutdown},
}
}

type prometheusProvider struct {
otelmetric.MeterProvider
shutdownFns []func(context.Context) error
}

func (p *prometheusProvider) Shutdown(ctx context.Context) error {
errs := make([]error, 0, len(p.shutdownFns))
for _, fn := range p.shutdownFns {
errs = append(errs, fn(ctx))
}
return errors.Join(errs...)
}

func res(logger *zap.SugaredLogger, cfg *config) *resource.Resource {
Expand Down
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