Allow specifying Collector's own Resource in the config

Resolves #5398

This adds a sub-section in the `service.telemetry` config section where any
Resource attributes can be specified.

For example we can have the following in the config:

service:
  telemetry:
    resource:
      service.instance.id: 01G3EN4NW306AFVGQT5ZYC0GEK
      service.namespace: onlineshop
      deployment.environment: production

CHANGELOG.md

@@ -21,6 +21,11 @@
 ### 💡 Enhancements 💡
 
 - Update OTLP to v0.17.0 (#5335)
+- User-defined Resource attributes can be specified under `service.telemetry.resource`
+  configuration key and will be included as metric lables for own telemetry.
+  If `service.instance.id` is not specified it will be auto-generated. Previously
+  `service.instance.id` was always auto-generated, so the default of the new
+  behavior matches the old behavior. (#5402)
 
 ### 🧰 Bug fixes 🧰
 

config/moved_service.go

@@ -36,8 +36,9 @@ type Service struct {
 // ServiceTelemetry defines the configurable settings for service telemetry.
 // Deprecated: [v0.52.0] Use service.ConfigServiceTelemetry
 type ServiceTelemetry struct {
-	Logs    ServiceTelemetryLogs    `mapstructure:"logs"`
-	Metrics ServiceTelemetryMetrics `mapstructure:"metrics"`
+	Logs     ServiceTelemetryLogs    `mapstructure:"logs"`
+	Metrics  ServiceTelemetryMetrics `mapstructure:"metrics"`
+	Resource map[string]string       `mapstructure:"resource"`
 }
 
 // ServiceTelemetryLogs defines the configurable settings for service telemetry logs.

service/collector_test.go

@@ -38,6 +38,7 @@ import (
 	"go.opentelemetry.io/collector/config/mapconverter/overwritepropertiesmapconverter"
 	"go.opentelemetry.io/collector/internal/testcomponents"
 	"go.opentelemetry.io/collector/internal/testutil"
+	"go.opentelemetry.io/collector/internal/version"
 	"go.opentelemetry.io/collector/service/featuregate"
 )
 
@@ -194,10 +195,25 @@ func testCollectorStartHelper(t *testing.T, telemetry collectorTelemetryExporter
 	cfgSet := newDefaultConfigProviderSettings([]string{
 		filepath.Join("testdata", "otelcol-config.yaml"),
 	})
+
+	// Define some Resource attributes.
+	userDefinedResource := map[string]string{
+		"custom_resource_attr": "resource_attr_test_value",
+	}
+
+	// Prepare config properties to be merged with the main config.
+	extraCfgAsProps := []string{
+		// Set the metrics address to expose own metrics on.
+		"service.telemetry.metrics.address=" + metricsAddr,
+	}
+	// Also include resource attributes under the service.telemetry.resource key.
+	for k, v := range userDefinedResource {
+		extraCfgAsProps = append(extraCfgAsProps,
+			"service.telemetry.resource."+k+"="+v)
+	}
+
 	cfgSet.MapConverters = append([]config.MapConverterFunc{
-		overwritepropertiesmapconverter.New(
-			[]string{"service.telemetry.metrics.address=" + metricsAddr},
-		)},
+		overwritepropertiesmapconverter.New(extraCfgAsProps)},
 		cfgSet.MapConverters...,
 	)
 	cfgProvider, err := NewConfigProvider(cfgSet)
@@ -226,9 +242,18 @@ func testCollectorStartHelper(t *testing.T, telemetry collectorTelemetryExporter
 	// and requires a good justification. The reason is that changes to metric
 	// names or labels can break alerting, dashboards, etc that are used to
 	// monitor the Collector in production deployments.
-	mandatoryLabels := []string{
-		"service_instance_id",
+	mandatoryLabels := map[string]string{
+		"service_instance_id": "", // Empty string means the value will not be asserted.
+	}
+	if AddCollectorVersionTag {
+		mandatoryLabels["service_version"] = version.Version
 	}
+
+	// Attributes of user defined Resource must also be included as labels of metrics.
+	for k, v := range userDefinedResource {
+		mandatoryLabels[k] = v
+	}
+
 	assertMetrics(t, metricsAddr, mandatoryLabels)
 
 	assertZPages(t)
@@ -316,7 +341,7 @@ func (tel *mockColTelemetry) shutdown() error {
 	return errors.New("err1")
 }
 
-func assertMetrics(t *testing.T, metricsAddr string, mandatoryLabels []string) {
+func assertMetrics(t *testing.T, metricsAddr string, mandatoryLabels map[string]string) {
 	client := &http.Client{}
 	resp, err := client.Get("http://" + metricsAddr + "/metrics")
 	require.NoError(t, err)
@@ -341,14 +366,17 @@ func assertMetrics(t *testing.T, metricsAddr string, mandatoryLabels []string) {
 			metricName[:len(prefix)+1]+"...")
 
 		for _, metric := range metricFamily.Metric {
-			var labelNames []string
+			labelMap := map[string]string{}
 			for _, labelPair := range metric.Label {
-				labelNames = append(labelNames, *labelPair.Name)
+				labelMap[*labelPair.Name] = *labelPair.Value
 			}
 
-			for _, mandatoryLabel := range mandatoryLabels {
+			for k, v := range mandatoryLabels {
 				// require is used here so test fails with a single message.
-				require.Contains(t, labelNames, mandatoryLabel, "mandatory label %q not present", mandatoryLabel)
+				require.NotEmpty(t, labelMap[k], "mandatory label %q not present", k)
+				if v != "" {
+					require.Equal(t, v, labelMap[k], "mandatory label %q value mismatch", k)
+				}
 			}
 		}
 	}

service/telemetry.go

@@ -94,6 +94,7 @@ func (tel *colTelemetry) init(col *Collector) error {
 func (tel *colTelemetry) initOnce(col *Collector) error {
 	logger := col.telemetry.Logger
 	cfg := col.service.config.Telemetry
+	resource := cfg.Resource
 
 	level := cfg.Metrics.Level
 	metricsAddr := cfg.Metrics.Address
@@ -109,8 +110,22 @@ func (tel *colTelemetry) initOnce(col *Collector) error {
 
 	logger.Info("Setting up own telemetry...")
 
-	instanceUUID, _ := uuid.NewRandom()
-	instanceID := instanceUUID.String()
+	if resource == nil {
+		resource = map[string]string{}
+	}
+
+	var instanceID string
+	instanceID = resource[semconv.AttributeServiceInstanceID]
+	if instanceID == "" {
+		// AttributeServiceInstanceID is not specified in the config. Auto-generate one.
+		instanceUUID, _ := uuid.NewRandom()
+		instanceID = instanceUUID.String()
+		resource[semconv.AttributeServiceInstanceID] = instanceID
+	}
+
+	if AddCollectorVersionTag {
+		resource[semconv.AttributeServiceVersion] = version.Version
+	}
 
 	var pe http.Handler
 	if tel.registry.IsEnabled(useOtelForInternalMetricsfeatureGateID) {
@@ -120,7 +135,7 @@ func (tel *colTelemetry) initOnce(col *Collector) error {
 		}
 		pe = otelHandler
 	} else {
-		ocHandler, err := tel.initOpenCensus(col, instanceID)
+		ocHandler, err := tel.initOpenCensus(col, resource)
 		if err != nil {
 			return err
 		}
@@ -131,8 +146,7 @@ func (tel *colTelemetry) initOnce(col *Collector) error {
 		"Serving Prometheus metrics",
 		zap.String(zapKeyTelemetryAddress, metricsAddr),
 		zap.String(zapKeyTelemetryLevel, level.String()),
-		zap.String(semconv.AttributeServiceInstanceID, instanceID),
-		zap.String(semconv.AttributeServiceVersion, version.Version),
+		zap.Any("Resource", resource),
 	)
 
 	mux := http.NewServeMux()
@@ -152,7 +166,7 @@ func (tel *colTelemetry) initOnce(col *Collector) error {
 	return nil
 }
 
-func (tel *colTelemetry) initOpenCensus(col *Collector, instanceID string) (http.Handler, error) {
+func (tel *colTelemetry) initOpenCensus(col *Collector, labels map[string]string) (http.Handler, error) {
 	processMetricsViews, err := telemetry2.NewProcessMetricsViews(getBallastSize(col.service.host))
 	if err != nil {
 		return nil, err
@@ -178,10 +192,8 @@ func (tel *colTelemetry) initOpenCensus(col *Collector, instanceID string) (http
 
 	opts.ConstLabels = make(map[string]string)
 
-	opts.ConstLabels[sanitizePrometheusKey(semconv.AttributeServiceInstanceID)] = instanceID
-
-	if AddCollectorVersionTag {
-		opts.ConstLabels[sanitizePrometheusKey(semconv.AttributeServiceVersion)] = version.Version
+	for k, v := range labels {
+		opts.ConstLabels[sanitizePrometheusKey(k)] = v
 	}
 
 	pe, err := prometheus.NewExporter(opts)