feat(nodejs-autoinstrumentation): enable overriding default histogram buckets

.chloggen/3436-nodejs-autosintrumentation-buckets.yaml

@@ -0,0 +1,16 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. collector, target allocator, auto-instrumentation, opamp, github action)
+component: auto-instrumentation
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Support overriding the default histogram bucket list via the `spec.nodejs.histogramBuckets` field on the Instrumentation Custom Resource.
+
+# One or more tracking issues related to the change
+issues: [3436]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

apis/v1alpha1/instrumentation_types.go

@@ -217,6 +217,15 @@
 	// Resources describes the compute resource requirements.
 	// +optional
 	Resources corev1.ResourceRequirements `json:"resourceRequirements,omitempty"`
+
+	// HistogramBuckets defines the histogram buckets for metrics generated by the NodeJS SDK.
+	// +optional
+	HistogramBuckets []HistogramBucketsItem `json:"histogramBuckets,omitempty"`
+}
+
+type HistogramBucketsItem struct {
+	Name    string    `json:"instrumentName"`
+	Buckets []float64 `json:"buckets"`
 }
 
 // Python defines Python SDK and instrumentation configuration.

autoinstrumentation/nodejs/src/autoinstrumentation.ts

@@ -4,7 +4,7 @@ import { OTLPTraceExporter as OTLPHttpTraceExporter } from '@opentelemetry/expor
 import { OTLPTraceExporter as OTLPGrpcTraceExporter } from '@opentelemetry/exporter-trace-otlp-grpc';
 import { OTLPMetricExporter } from '@opentelemetry/exporter-metrics-otlp-grpc';
 import { PrometheusExporter } from '@opentelemetry/exporter-prometheus';
-import { PeriodicExportingMetricReader } from '@opentelemetry/sdk-metrics';
+import { ExplicitBucketHistogramAggregation, PeriodicExportingMetricReader, View } from "@opentelemetry/sdk-metrics";
 import { alibabaCloudEcsDetector } from '@opentelemetry/resource-detector-alibaba-cloud';
 import { awsEc2Detector, awsEksDetector } from '@opentelemetry/resource-detector-aws';
 import { containerDetector } from '@opentelemetry/resource-detector-container';
@@ -50,11 +50,39 @@ function getMetricReader() {
     }
 }
 
+function getViews() {
+  const histogramBuckets = process.env.OTEL_OPERATOR_NODEJS_HISTOGRAM_BUCKETS;
+  if (histogramBuckets) {
+    try {
+      let views = [];
+      for (const viewCfg of JSON.parse(histogramBuckets)) {
+        views.push(
+          new View({
+            instrumentName: viewCfg["instrumentName"],
+            aggregation: new ExplicitBucketHistogramAggregation(
+              viewCfg["buckets"],
+            ),
+          }),
+        );
+      }
+      return views;
+    } catch (error) {
+      diag.error(
+        "Failed to parse OTEL_OPERATOR_NODEJS_HISTOGRAM_BUCKETS:",
+        error,
+      );
+    }
+    return [];
+  }
+  return [];
+}
+
 const sdk = new NodeSDK({
     autoDetectResources: true,
     instrumentations: [getNodeAutoInstrumentations()],
     traceExporter: getTraceExporter(),
     metricReader: getMetricReader(),
+    views: getViews(),
     resourceDetectors:
         [
             // Standard resource detectors.
@@ -75,3 +103,4 @@ const sdk = new NodeSDK({
 });
 
 sdk.start();
+

config/crd/bases/opentelemetry.io_instrumentations.yaml

@@ -1393,6 +1393,17 @@ spec:
                 type: object
               nodejs:
                 properties:
+                  histogramBuckets:
+                    type: array
+                    items:
+                      type: object
+                      properties:
+                        instrumentName:
+                          type: string
+                        buckets:
+                          type: array
+                          items:
+                            type: number
                   env:
                     items:
                       properties:

pkg/instrumentation/nodejs.go

@@ -16,7 +16,7 @@ package instrumentation
 
 import (
 	corev1 "k8s.io/api/core/v1"
-
+  "encoding/json"
 	"github.com/open-telemetry/opentelemetry-operator/apis/v1alpha1"
 )
 
@@ -26,9 +26,25 @@ const (
 	nodejsInitContainerName = initContainerName + "-nodejs"
 	nodejsVolumeName        = volumeName + "-nodejs"
 	nodejsInstrMountPath    = "/otel-auto-instrumentation-nodejs"
+	histogramBucketsEnvVarName = "OTEL_OPERATOR_NODEJS_HISTOGRAM_BUCKETS"
 )
 
 func injectNodeJSSDK(nodeJSSpec v1alpha1.NodeJS, pod corev1.Pod, index int) (corev1.Pod, error) {
+  if len(nodeJSSpec.HistogramBuckets) > 0 {
+		bucketsJSON, err := json.Marshal(nodeJSSpec.HistogramBuckets)
+	  if err != nil {
+			// handle error, possibly log and skip injection for this resource
+			return pod, err
+		}
+
+		// Inject as an environment variable in the pod
+		bucketsJSONEnvVar := corev1.EnvVar{
+			Name:  histogramBucketsEnvVarName,
+			Value: string(bucketsJSON),
+		}
+		nodeJSSpec.Env = append(nodeJSSpec.Env, bucketsJSONEnvVar)
+	}
+
 	volume := instrVolume(nodeJSSpec.VolumeClaimTemplate, nodejsVolumeName, nodeJSSpec.VolumeSizeLimit)
 
 	// caller checks if there is at least one container.