include a flag to disable metric prefixes

metrics/config.go

@@ -28,6 +28,7 @@ import (
 
 	"go.opencensus.io/stats"
 	corev1 "k8s.io/api/core/v1"
+	"knative.dev/pkg/configmap"
 	"knative.dev/pkg/metrics/metricskey"
 )
 
@@ -43,9 +44,11 @@ const (
 	// The following keys are used to configure metrics reporting.
 	// See https://github.com/knative/serving/blob/main/config/config-observability.yaml
 	// for details.
-	collectorAddressKey = "metrics.opencensus-address"
-	collectorSecureKey  = "metrics.opencensus-require-tls"
-	reportingPeriodKey  = "metrics.reporting-period-seconds"
+	collectorAddressKey             = "metrics.opencensus-address"
+	collectorSecureKey              = "metrics.opencensus-require-tls"
+	reportingPeriodKey              = "metrics.reporting-period-seconds"
+	enableDeprecatedMetricPrefixKey = "metrics.enable-deprecated-name-prefix"
+	requestMetricsBackendKey        = "metrics.request-metrics-backend-destination"
 
 	defaultBackendEnvName = "DEFAULT_METRICS_BACKEND"
 	defaultPrometheusPort = 9090
@@ -84,6 +87,9 @@ type metricsConfig struct {
 	// If duration is less than or equal to zero, it enables the default behavior.
 	reportingPeriod time.Duration
 
+	// whether or not we prefix the metric name with the domain and/or component
+	enableDeprecatedMetricPrefix bool
+
 	// recorder provides a hook for performing custom transformations before
 	// writing the metrics to the stats.RecordWithOptions interface.
 	recorder func(context.Context, []stats.Measurement, ...stats.Options) error
@@ -220,6 +226,14 @@ func createMetricsConfig(_ context.Context, ops ExporterOptions) (*metricsConfig
 			mc.reportingPeriod = 5 * time.Second
 		}
 	}
+
+	err := configmap.Parse(m,
+		configmap.AsBool(enableDeprecatedMetricPrefixKey, &mc.enableDeprecatedMetricPrefix))
+
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse %s: %w", enableDeprecatedMetricPrefixKey, err)
+	}
+
 	return &mc, nil
 }
 

metrics/config_observability.go

@@ -79,13 +79,22 @@ type ObservabilityConfig struct {
 	// MetricsCollectorAddress specifies the metrics collector address. This is only used
 	// when the metrics backend is opencensus.
 	MetricsCollectorAddress string
+
+	// EnableDeprecatedMetricPrefix retains the legacy behaviour of prefixing our metric names
+	// with either the component name and/or metric domain
+	//
+	// When enabled:
+	// - OpenCensus exporter prefixes the domain and component
+	// - Prometheus exporter prefixes the component name (as a prom namespace)
+	EnableDeprecatedMetricPrefix bool
 }
 
 func defaultConfig() *ObservabilityConfig {
 	return &ObservabilityConfig{
-		LoggingURLTemplate:    DefaultLogURLTemplate,
-		RequestLogTemplate:    DefaultRequestLogTemplate,
-		RequestMetricsBackend: defaultRequestMetricsBackend,
+		LoggingURLTemplate:           DefaultLogURLTemplate,
+		RequestLogTemplate:           DefaultRequestLogTemplate,
+		RequestMetricsBackend:        defaultRequestMetricsBackend,
+		EnableDeprecatedMetricPrefix: true,
 	}
 }
 
@@ -97,11 +106,12 @@ func NewObservabilityConfigFromConfigMap(configMap *corev1.ConfigMap) (*Observab
 		cm.AsBool("logging.enable-var-log-collection", &oc.EnableVarLogCollection),
 		cm.AsString("logging.revision-url-template", &oc.LoggingURLTemplate),
 		cm.AsString(ReqLogTemplateKey, &oc.RequestLogTemplate),
+		cm.AsBool("profiling.enable", &oc.EnableProfiling),
 		cm.AsBool(EnableReqLogKey, &oc.EnableRequestLog),
 		cm.AsBool(EnableProbeReqLogKey, &oc.EnableProbeRequestLog),
-		cm.AsString("metrics.request-metrics-backend-destination", &oc.RequestMetricsBackend),
-		cm.AsBool("profiling.enable", &oc.EnableProfiling),
-		cm.AsString("metrics.opencensus-address", &oc.MetricsCollectorAddress),
+		cm.AsString(requestMetricsBackendKey, &oc.RequestMetricsBackend),
+		cm.AsString(collectorAddressKey, &oc.MetricsCollectorAddress),
+		cm.AsBool(enableDeprecatedMetricPrefixKey, &oc.EnableDeprecatedMetricPrefix),
 	); err != nil {
 		return nil, err
 	}

metrics/config_observability_test.go

@@ -35,22 +35,24 @@ func TestObservabilityConfiguration(t *testing.T) {
 	}{{
 		name: "observability configuration with all inputs",
 		wantConfig: &ObservabilityConfig{
-			EnableProbeRequestLog:  true,
-			EnableProfiling:        true,
-			EnableVarLogCollection: true,
-			EnableRequestLog:       true,
-			LoggingURLTemplate:     "https://logging.io",
-			RequestLogTemplate:     `{"requestMethod": "{{.Request.Method}}"}`,
-			RequestMetricsBackend:  "opencensus",
+			EnableProbeRequestLog:        true,
+			EnableProfiling:              true,
+			EnableVarLogCollection:       true,
+			EnableRequestLog:             true,
+			EnableDeprecatedMetricPrefix: false,
+			LoggingURLTemplate:           "https://logging.io",
+			RequestLogTemplate:           `{"requestMethod": "{{.Request.Method}}"}`,
+			RequestMetricsBackend:        "opencensus",
 		},
 		data: map[string]string{
-			EnableProbeReqLogKey:                          "true",
-			"logging.enable-var-log-collection":           "true",
-			ReqLogTemplateKey:                             `{"requestMethod": "{{.Request.Method}}"}`,
-			"logging.revision-url-template":               "https://logging.io",
-			EnableReqLogKey:                               "true",
-			"metrics.request-metrics-backend-destination": "opencensus",
-			"profiling.enable":                            "true",
+			EnableProbeReqLogKey:                "true",
+			"logging.enable-var-log-collection": "true",
+			ReqLogTemplateKey:                   `{"requestMethod": "{{.Request.Method}}"}`,
+			"logging.revision-url-template":     "https://logging.io",
+			EnableReqLogKey:                     "true",
+			"profiling.enable":                  "true",
+			requestMetricsBackendKey:            "opencensus",
+			enableDeprecatedMetricPrefixKey:     "false",
 		},
 	}, {
 		name:       "observability config with no map",

metrics/e2e_test.go

@@ -95,9 +95,10 @@ func TestMetricsExport(t *testing.T) {
 			Component:      testComponent,
 			PrometheusPort: prometheusPort,
 			ConfigMap: map[string]string{
-				BackendDestinationKey: string(backend),
-				collectorAddressKey:   ocFake.address,
-				reportingPeriodKey:    "1",
+				BackendDestinationKey:           string(backend),
+				collectorAddressKey:             ocFake.address,
+				reportingPeriodKey:              "1",
+				enableDeprecatedMetricPrefixKey: "true",
 			},
 		}
 	}

metrics/opencensus_exporter.go

@@ -37,7 +37,7 @@ func newOpenCensusExporter(config *metricsConfig, logger *zap.SugaredLogger) (vi
 		opts = append(opts, ocagent.WithAddress(config.collectorAddress))
 	}
 	metrixPrefix := path.Join(config.domain, config.component)
-	if metrixPrefix != "" {
+	if metrixPrefix != "" && config.enableDeprecatedMetricPrefix {
 		opts = append(opts, ocagent.WithMetricNamePrefix(metrixPrefix))
 	}
 	if config.requireSecure {

metrics/prometheus_exporter.go

@@ -43,7 +43,11 @@ func (emptyPromExporter) ExportView(viewData *view.Data) {
 
 //nolint: unparam // False positive of flagging the second result of this function unused.
 func newPrometheusExporter(config *metricsConfig, logger *zap.SugaredLogger) (view.Exporter, ResourceExporterFactory, error) {
-	e, err := prom.NewExporter(prom.Options{Namespace: config.component})
+	opts := prom.Options{}
+	if config.enableDeprecatedMetricPrefix {
+		opts.Namespace = config.component
+	}
+	e, err := prom.NewExporter(opts)
 	if err != nil {
 		logger.Errorw("Failed to create the Prometheus exporter.", zap.Error(err))
 		return nil, nil, err

metrics/prometheus_exporter_test.go

@@ -29,11 +29,12 @@ func TestNewPrometheusExporter(t *testing.T) {
 	}{{
 		name: "port 9090",
 		config: metricsConfig{
-			domain:             "does not matter",
-			component:          testComponent,
-			backendDestination: prometheus,
-			prometheusPort:     9090,
-			prometheusHost:     "0.0.0.0",
+			domain:                       "does not matter",
+			component:                    testComponent,
+			backendDestination:           prometheus,
+			enableDeprecatedMetricPrefix: true,
+			prometheusPort:               9090,
+			prometheusHost:               "0.0.0.0",
 		},
 		expectedAddr: "0.0.0.0:9090",
 	}, {