package metrics import ( "context" "fmt" "net" "strings" "sync" "time" "github.com/go-kit/kit/metrics" "github.com/rs/zerolog/log" "github.com/traefik/traefik/v3/pkg/types" "github.com/traefik/traefik/v3/pkg/version" "go.opentelemetry.io/otel/attribute" "go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc" "go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp" "go.opentelemetry.io/otel/metric" "go.opentelemetry.io/otel/metric/global" "go.opentelemetry.io/otel/metric/instrument" "go.opentelemetry.io/otel/metric/instrument/asyncfloat64" "go.opentelemetry.io/otel/metric/instrument/syncfloat64" "go.opentelemetry.io/otel/metric/unit" sdkmetric "go.opentelemetry.io/otel/sdk/metric" "go.opentelemetry.io/otel/sdk/metric/aggregation" "go.opentelemetry.io/otel/sdk/resource" semconv "go.opentelemetry.io/otel/semconv/v1.12.0" "google.golang.org/grpc/credentials" "google.golang.org/grpc/encoding/gzip" ) var ( openTelemetryMeterProvider *sdkmetric.MeterProvider openTelemetryGaugeCollector *gaugeCollector ) // RegisterOpenTelemetry registers all OpenTelemetry metrics. func RegisterOpenTelemetry(ctx context.Context, config *types.OpenTelemetry) Registry { if openTelemetryMeterProvider == nil { var err error if openTelemetryMeterProvider, err = newOpenTelemetryMeterProvider(ctx, config); err != nil { log.Ctx(ctx).Err(err).Msg("Unable to create OpenTelemetry meter provider") return nil } } if openTelemetryGaugeCollector == nil { openTelemetryGaugeCollector = newOpenTelemetryGaugeCollector() } meter := global.Meter("github.com/traefik/traefik", metric.WithInstrumentationVersion(version.Version)) reg := &standardRegistry{ epEnabled: config.AddEntryPointsLabels, routerEnabled: config.AddRoutersLabels, svcEnabled: config.AddServicesLabels, configReloadsCounter: newOTLPCounterFrom(meter, configReloadsTotalName, "Config reloads"), lastConfigReloadSuccessGauge: newOTLPGaugeFrom(meter, configLastReloadSuccessName, "Last config reload success", unit.Milliseconds), openConnectionsGauge: newOTLPGaugeFrom(meter, openConnectionsName, "How many open connections exist, by entryPoint and protocol", unit.Dimensionless), tlsCertsNotAfterTimestampGauge: newOTLPGaugeFrom(meter, tlsCertsNotAfterTimestampName, "Certificate expiration timestamp", unit.Milliseconds), } if config.AddEntryPointsLabels { reg.entryPointReqsCounter = NewCounterWithNoopHeaders(newOTLPCounterFrom(meter, entryPointReqsTotalName, "How many HTTP requests processed on an entrypoint, partitioned by status code, protocol, and method.")) reg.entryPointReqsTLSCounter = newOTLPCounterFrom(meter, entryPointReqsTLSTotalName, "How many HTTP requests with TLS processed on an entrypoint, partitioned by TLS Version and TLS cipher Used.") reg.entryPointReqDurationHistogram, _ = NewHistogramWithScale(newOTLPHistogramFrom(meter, entryPointReqDurationName, "How long it took to process the request on an entrypoint, partitioned by status code, protocol, and method.", unit.Milliseconds), time.Second) } if config.AddRoutersLabels { reg.routerReqsCounter = NewCounterWithNoopHeaders(newOTLPCounterFrom(meter, routerReqsTotalName, "How many HTTP requests are processed on a router, partitioned by service, status code, protocol, and method.")) reg.routerReqsTLSCounter = newOTLPCounterFrom(meter, routerReqsTLSTotalName, "How many HTTP requests with TLS are processed on a router, partitioned by service, TLS Version, and TLS cipher Used.") reg.routerReqDurationHistogram, _ = NewHistogramWithScale(newOTLPHistogramFrom(meter, routerReqDurationName, "How long it took to process the request on a router, partitioned by service, status code, protocol, and method.", unit.Milliseconds), time.Second) } if config.AddServicesLabels { reg.serviceReqsCounter = NewCounterWithNoopHeaders(newOTLPCounterFrom(meter, serviceReqsTotalName, "How many HTTP requests processed on a service, partitioned by status code, protocol, and method.")) reg.serviceReqsTLSCounter = newOTLPCounterFrom(meter, serviceReqsTLSTotalName, "How many HTTP requests with TLS processed on a service, partitioned by TLS version and TLS cipher.") reg.serviceReqDurationHistogram, _ = NewHistogramWithScale(newOTLPHistogramFrom(meter, serviceReqDurationName, "How long it took to process the request on a service, partitioned by status code, protocol, and method.", unit.Milliseconds), time.Second) reg.serviceRetriesCounter = newOTLPCounterFrom(meter, serviceRetriesTotalName, "How many request retries happened on a service.") reg.serviceServerUpGauge = newOTLPGaugeFrom(meter, serviceServerUpName, "service server is up, described by gauge value of 0 or 1.", unit.Dimensionless) } return reg } // StopOpenTelemetry stops and resets Open-Telemetry client. func StopOpenTelemetry() { if openTelemetryMeterProvider == nil { return } ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second) defer cancel() if err := openTelemetryMeterProvider.Shutdown(ctx); err != nil { log.Err(err).Msg("Unable to shutdown OpenTelemetry meter provider") } openTelemetryMeterProvider = nil } // newOpenTelemetryMeterProvider creates a new controller.Controller. func newOpenTelemetryMeterProvider(ctx context.Context, config *types.OpenTelemetry) (*sdkmetric.MeterProvider, error) { var ( exporter sdkmetric.Exporter err error ) if config.GRPC != nil { exporter, err = newGRPCExporter(ctx, config) } else { exporter, err = newHTTPExporter(ctx, config) } if err != nil { return nil, fmt.Errorf("creating exporter: %w", err) } res, err := resource.New(ctx, resource.WithAttributes(semconv.ServiceNameKey.String("traefik")), resource.WithAttributes(semconv.ServiceVersionKey.String(version.Version)), resource.WithFromEnv(), resource.WithTelemetrySDK(), ) if err != nil { return nil, fmt.Errorf("building resource: %w", err) } opts := []sdkmetric.PeriodicReaderOption{ sdkmetric.WithInterval(time.Duration(config.PushInterval)), } meterProvider := sdkmetric.NewMeterProvider( sdkmetric.WithResource(res), sdkmetric.WithReader(sdkmetric.NewPeriodicReader(exporter, opts...)), // View to customize histogram buckets and rename a single histogram instrument. sdkmetric.WithView(sdkmetric.NewView( sdkmetric.Instrument{Name: "traefik_*_request_duration_seconds"}, sdkmetric.Stream{Aggregation: aggregation.ExplicitBucketHistogram{ Boundaries: config.ExplicitBoundaries, }}, )), ) global.SetMeterProvider(meterProvider) return meterProvider, nil } func newHTTPExporter(ctx context.Context, config *types.OpenTelemetry) (sdkmetric.Exporter, error) { host, port, err := net.SplitHostPort(config.Address) if err != nil { return nil, fmt.Errorf("invalid collector address %q: %w", config.Address, err) } opts := []otlpmetrichttp.Option{ otlpmetrichttp.WithEndpoint(fmt.Sprintf("%s:%s", host, port)), otlpmetrichttp.WithHeaders(config.Headers), otlpmetrichttp.WithCompression(otlpmetrichttp.GzipCompression), } if config.Insecure { opts = append(opts, otlpmetrichttp.WithInsecure()) } if config.Path != "" { opts = append(opts, otlpmetrichttp.WithURLPath(config.Path)) } if config.TLS != nil { tlsConfig, err := config.TLS.CreateTLSConfig(ctx) if err != nil { return nil, fmt.Errorf("creating TLS client config: %w", err) } opts = append(opts, otlpmetrichttp.WithTLSClientConfig(tlsConfig)) } return otlpmetrichttp.New(ctx, opts...) } func newGRPCExporter(ctx context.Context, config *types.OpenTelemetry) (sdkmetric.Exporter, error) { host, port, err := net.SplitHostPort(config.Address) if err != nil { return nil, fmt.Errorf("invalid collector address %q: %w", config.Address, err) } opts := []otlpmetricgrpc.Option{ otlpmetricgrpc.WithEndpoint(fmt.Sprintf("%s:%s", host, port)), otlpmetricgrpc.WithHeaders(config.Headers), otlpmetricgrpc.WithCompressor(gzip.Name), } if config.Insecure { opts = append(opts, otlpmetricgrpc.WithInsecure()) } if config.TLS != nil { tlsConfig, err := config.TLS.CreateTLSConfig(ctx) if err != nil { return nil, fmt.Errorf("creating TLS client config: %w", err) } opts = append(opts, otlpmetricgrpc.WithTLSCredentials(credentials.NewTLS(tlsConfig))) } return otlpmetricgrpc.New(ctx, opts...) } func newOTLPCounterFrom(meter metric.Meter, name, desc string) *otelCounter { c, _ := meter.SyncFloat64().Counter(name, instrument.WithDescription(desc), instrument.WithUnit(unit.Dimensionless), ) return &otelCounter{ ip: c, } } type otelCounter struct { labelNamesValues otelLabelNamesValues ip syncfloat64.Counter } func (c *otelCounter) With(labelValues ...string) metrics.Counter { return &otelCounter{ labelNamesValues: c.labelNamesValues.With(labelValues...), ip: c.ip, } } func (c *otelCounter) Add(delta float64) { c.ip.Add(context.Background(), delta, c.labelNamesValues.ToLabels()...) } type gaugeValue struct { attributes otelLabelNamesValues value float64 } type gaugeCollector struct { mu sync.Mutex values map[string]map[string]gaugeValue } func newOpenTelemetryGaugeCollector() *gaugeCollector { return &gaugeCollector{ values: make(map[string]map[string]gaugeValue), } } func (c *gaugeCollector) add(name string, delta float64, attributes otelLabelNamesValues) { c.mu.Lock() defer c.mu.Unlock() str := strings.Join(attributes, "") if _, exists := c.values[name]; !exists { c.values[name] = map[string]gaugeValue{ str: { attributes: attributes, value: delta, }, } return } v, exists := c.values[name][str] if !exists { c.values[name][str] = gaugeValue{ attributes: attributes, value: delta, } return } c.values[name][str] = gaugeValue{ attributes: attributes, value: v.value + delta, } } func (c *gaugeCollector) set(name string, value float64, attributes otelLabelNamesValues) { c.mu.Lock() defer c.mu.Unlock() if _, exists := c.values[name]; !exists { c.values[name] = make(map[string]gaugeValue) } c.values[name][strings.Join(attributes, "")] = gaugeValue{ attributes: attributes, value: value, } } func newOTLPGaugeFrom(meter metric.Meter, name, desc string, u unit.Unit) *otelGauge { openTelemetryGaugeCollector.values[name] = make(map[string]gaugeValue) c, _ := meter.AsyncFloat64().Gauge(name, instrument.WithDescription(desc), instrument.WithUnit(u), ) err := meter.RegisterCallback([]instrument.Asynchronous{c}, func(ctx context.Context) { openTelemetryGaugeCollector.mu.Lock() defer openTelemetryGaugeCollector.mu.Unlock() values, exists := openTelemetryGaugeCollector.values[name] if !exists { return } for _, value := range values { c.Observe(ctx, value.value, value.attributes.ToLabels()...) } }) if err != nil { log.Err(err).Msg("Unable to register OpenTelemetry meter callback") } return &otelGauge{ ip: c, name: name, } } type otelGauge struct { labelNamesValues otelLabelNamesValues ip asyncfloat64.Gauge name string } func (g *otelGauge) With(labelValues ...string) metrics.Gauge { return &otelGauge{ labelNamesValues: g.labelNamesValues.With(labelValues...), ip: g.ip, name: g.name, } } func (g *otelGauge) Add(delta float64) { openTelemetryGaugeCollector.add(g.name, delta, g.labelNamesValues) } func (g *otelGauge) Set(value float64) { openTelemetryGaugeCollector.set(g.name, value, g.labelNamesValues) } func newOTLPHistogramFrom(meter metric.Meter, name, desc string, u unit.Unit) *otelHistogram { c, _ := meter.SyncFloat64().Histogram(name, instrument.WithDescription(desc), instrument.WithUnit(u), ) return &otelHistogram{ ip: c, } } type otelHistogram struct { labelNamesValues otelLabelNamesValues ip syncfloat64.Histogram } func (h *otelHistogram) With(labelValues ...string) metrics.Histogram { return &otelHistogram{ labelNamesValues: h.labelNamesValues.With(labelValues...), ip: h.ip, } } func (h *otelHistogram) Observe(incr float64) { h.ip.Record(context.Background(), incr, h.labelNamesValues.ToLabels()...) } // otelLabelNamesValues is the equivalent of prometheus' labelNamesValues // but adapted to OpenTelemetry. // otelLabelNamesValues is a type alias that provides validation on its With // method. // Metrics may include it as a member to help them satisfy With semantics and // save some code duplication. type otelLabelNamesValues []string // With validates the input, and returns a new aggregate otelLabelNamesValues. func (lvs otelLabelNamesValues) With(labelValues ...string) otelLabelNamesValues { if len(labelValues)%2 != 0 { labelValues = append(labelValues, "unknown") } return append(lvs, labelValues...) } // ToLabels is a convenience method to convert a otelLabelNamesValues // to the native attribute.KeyValue. func (lvs otelLabelNamesValues) ToLabels() []attribute.KeyValue { labels := make([]attribute.KeyValue, len(lvs)/2) for i := 0; i < len(labels); i++ { labels[i] = attribute.String(lvs[2*i], lvs[2*i+1]) } return labels }