Expose application and system metrics on the same port

Signed-off-by: Jessica He <jhe@redhat.com>

docs/monitoring-and-logging.md

@@ -1,8 +1,6 @@
 # Setting up Metrics Monitoring and Logging for Backstage Showcase
 
-The Backstage Showcase provides a `/metrics` endpoint on port `9464` (for application metrics) and `9463` (for host metrics) that provides OpenTelemetry metrics about your backstage application. This endpoint can be used to monitor your backstage instance using OpenTelemetry and Grafana.
-
-**Note**: Due to a limitation, the host and application metrics are exposed on separate ports. This is to be improved by making all metrics accessible on the same port (9464) in a future release. This guide will ONLY work with the application metrics from NodeJs and Backstage.
+The Backstage Showcase provides a `/metrics` endpoint on port `9464` that provides OpenTelemetry metrics about your backstage application. This endpoint can be used to monitor your backstage instance using OpenTelemetry and Grafana.
 
 When deploying Backstage Showcase onto a kubernetes cluster with the [RHDH Helm chart](https://github.com/redhat-developer/rhdh-chart) or the [RHDH Operator](https://github.com/janus-idp/operator), monitoring and logging for your RHDH instance can be configured using the following steps.
 

packages/backend/package.json

@@ -51,6 +51,7 @@
     "@internal/plugin-scalprum-backend": "*",
     "@janus-idp/backstage-plugin-audit-log-node": "1.7.0",
     "@janus-idp/backstage-scaffolder-backend-module-annotator": "2.2.0",
+    "@opentelemetry/api": "1.9.0",
     "@opentelemetry/auto-instrumentations-node": "0.50.2",
     "@opentelemetry/exporter-prometheus": "0.53.0",
     "@opentelemetry/host-metrics": "0.35.4",

packages/backend/src/instrumentation.js

@@ -7,12 +7,12 @@ const {
 } = require('@opentelemetry/instrumentation-runtime-node');
 const { PrometheusExporter } = require('@opentelemetry/exporter-prometheus');
 const { HostMetrics } = require('@opentelemetry/host-metrics');
-const { MeterProvider } = require('@opentelemetry/sdk-metrics');
+const { metrics } = require('@opentelemetry/api');
 
-// Application metrics will be exported to localhost:9464/metrics
-const prometheusApplication = new PrometheusExporter();
+// Metrics will be exported to localhost:9464/metrics
+const prometheus = new PrometheusExporter();
 const sdk = new NodeSDK({
-  metricReader: prometheusApplication,
+  metricReader: prometheus,
   instrumentations: [
     getNodeAutoInstrumentations(),
     new RuntimeNodeInstrumentation(),
@@ -21,10 +21,7 @@ const sdk = new NodeSDK({
 
 sdk.start();
 
-// Host/process metrics will be exported to localhost:9463/metrics
-const prometheusHost = new PrometheusExporter({ port: 9463 });
-const meterProvider = new MeterProvider({
-  readers: [prometheusHost],
+const hostMetrics = new HostMetrics({
+  meterProvider: metrics.getMeterProvider(),
 });
-const hostMetrics = new HostMetrics({ meterProvider });
 hostMetrics.start();

yarn.lock

@@ -13986,7 +13986,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@opentelemetry/api@npm:^1.0.0, @opentelemetry/api@npm:^1.0.1, @opentelemetry/api@npm:^1.3.0, @opentelemetry/api@npm:^1.4.0":
+"@opentelemetry/api@npm:1.9.0, @opentelemetry/api@npm:^1.0.0, @opentelemetry/api@npm:^1.0.1, @opentelemetry/api@npm:^1.3.0, @opentelemetry/api@npm:^1.4.0":
   version: 1.9.0
   resolution: "@opentelemetry/api@npm:1.9.0"
   checksum: 9e88e59d53ced668f3daaecfd721071c5b85a67dd386f1c6f051d1be54375d850016c881f656ffbe9a03bedae85f7e89c2f2b635313f9c9b195ad033cdc31020
@@ -22453,6 +22453,7 @@ __metadata:
     "@internal/plugin-scalprum-backend": "*"
     "@janus-idp/backstage-plugin-audit-log-node": 1.7.0
     "@janus-idp/backstage-scaffolder-backend-module-annotator": 2.2.0
+    "@opentelemetry/api": 1.9.0
     "@opentelemetry/auto-instrumentations-node": 0.50.2
     "@opentelemetry/exporter-prometheus": 0.53.0
     "@opentelemetry/host-metrics": 0.35.4