feat(nodejs-autoinstrumentation): enable overwriting default histogra…

…m buckets

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 +50,35 @@ function getMetricReader() {
     }
 }
 
+function getView() {
+  const buckets = process.env.OTEL_METRICS_EXPLICIT_BUCKET_HISTOGRAM;
+  const defaultHistogramBuckets = [
+    0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1, 2.5, 5, 7.5, 10,
+  ];
+  if (!buckets) {
+    return new View({
+      aggregation: new ExplicitBucketHistogramAggregation(
+        defaultHistogramBuckets,
+      ),
+      instrumentName: "*",
+    });
+  } else {
+    return new View({
+      // parse buckets and make it a list of numbers
+      aggregation: new ExplicitBucketHistogramAggregation(
+        buckets.split(",").map((x) => parseFloat(x)),
+      ),
+      instrumentName: "*",
+    });
+  }
+}
+
 const sdk = new NodeSDK({
     autoDetectResources: true,
     instrumentations: [getNodeAutoInstrumentations()],
     traceExporter: getTraceExporter(),
     metricReader: getMetricReader(),
+    views: [getView()],
     resourceDetectors:
         [
             // Standard resource detectors.