initial commit: emit gauge metrics to Levitate

Author: anik3tra0

.github/workflows/docker-image.yml

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+name: Publish docker image
+
+on:
+  release:
+    types:
+      - created
+
+jobs:
+  publish:
+    name: Build and publish docker image
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out the repo
+        uses: actions/checkout@v2
+
+      - name: Set IMAGE_TAG
+        run: |
+          VERSION=$(cat package.json | grep version | awk -F '\"' '{ print $4 }')
+          TS=$(date +'%d%m%y%H%M')
+          IMAGE_TAG="${VERSION}-${TS}"
+          echo "IMAGE_TAG=$IMAGE_TAG" >> $GITHUB_ENV
+
+      - name: Set up docker hub credentials
+        env:
+          LAST9_DOCKER_AUTH: ${{secrets.LAST9_DOCKER_AUTH}}
+        run: |
+          mkdir -p ~/.docker
+          cat > ~/.docker/config.json <<EOF
+            {
+              "auths": {
+                "docker-registry.last9.io": {
+                  "auth": "${LAST9_DOCKER_AUTH}"
+                }
+              }
+            }
+          EOF
+
+      - name: Build new docker image
+        run: |
+          docker build -t docker-registry.last9.io/last9-nodejs-otel-example/nodejs-otel:${IMAGE_TAG} .
+          docker build -t docker-registry.last9.io/last9-nodejs-otel-example/nodejs-otel:latest .
+
+      - name: Publish the new docker image to internal registry
+        run: |
+          docker login docker-registry.last9.io
+          docker push docker-registry.last9.io/last9-nodejs-otel-example/nodejs-otel:${IMAGE_TAG}
+          docker push docker-registry.last9.io/last9-nodejs-otel-example/nodejs-otel:latest

.gitignore

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+node_modules
+.idea

Dockerfile

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+# Use the official Node.js 18 image as a parent image
+FROM node:18
+
+# Set the working directory in the container
+WORKDIR /usr/src/app
+
+# Copy package.json and package-lock.json
+COPY package*.json ./
+
+# Install dependencies
+RUN npm install
+
+# Copy the application code to the container
+COPY . .
+
+CMD [ "node", "app.js" ]

app.js

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+'use strict';
+
+const {DiagConsoleLogger, DiagLogLevel, ValueType, diag} = require('@opentelemetry/api');
+const {OTLPMetricExporter} = require('@opentelemetry/exporter-metrics-otlp-proto');
+
+const {
+  ExponentialHistogramAggregation, MeterProvider, PeriodicExportingMetricReader, View,
+} = require('@opentelemetry/sdk-metrics');
+const {Resource} = require('@opentelemetry/resources');
+const {
+  SemanticResourceAttributes,
+} = require('@opentelemetry/semantic-conventions');
+const os = require('os');
+const {v4: uuidv4} = require('uuid');
+const metricPrefix = process.env.METRIC_PREFIX
+const workflowIDCount = parseInt(process.env.WORKFLOW_ID_COUNT);
+const customerIDCount = parseInt(process.env.CUSTOMER_ID_COUNT);
+const otlpEndpoint = process.env.OTLP_ENDPOINT;
+const serviceName = process.env.SERVICE_NAME;
+const otelMetricExporterFrequency = parseInt(process.env.OTLP_METRIC_EXPORTER_FREQUENCY);
+const otelMeterName = process.env.OTLP_METER_NAME;
+const environment = process.env.ENVIRONMENT;
+
+// Global variables
+// Toggle this number below to explode cardinality.
+const workflowIDs = Array.from({length: workflowIDCount}, () => uuidv4());
+const customerIDs = Array.from({length: customerIDCount}, () => uuidv4());
+
+
+// Optional and only needed to see the internal diagnostic logging (during development)
+diag.setLogger(new DiagConsoleLogger(), DiagLogLevel.DEBUG);
+
+const metricExporter = new OTLPMetricExporter({
+  url: otlpEndpoint
+});
+
+// Create an instance of the metric provider
+const meterProvider = new MeterProvider({
+  resource: new Resource({
+    [SemanticResourceAttributes.SERVICE_NAME]: serviceName,
+  })
+});
+
+meterProvider.addMetricReader(new PeriodicExportingMetricReader({
+  exporter: metricExporter, // exporter: new ConsoleMetricExporter(),
+  exportIntervalMillis: otelMetricExporterFrequency,
+}));
+
+const meter = meterProvider.getMeter(otelMeterName);
+
+// Create Observable Gauges
+const memoryUsageGauge = meter.createObservableGauge(`${metricPrefix}_memory_usage`, {
+  description: 'Tracks the memory usage of the application', valueType: ValueType.DOUBLE
+});
+
+const concurrencyGauge = meter.createObservableGauge(`${metricPrefix}_concurrency`, {
+  description: 'Current concurrency level', valueType: ValueType.INT
+});
+
+const cpuUsageGauge = meter.createObservableGauge(`${metricPrefix}_cpu_usage`, {
+  description: 'CPU usage percentage', valueType: ValueType.DOUBLE
+});
+
+const runInTimeGauge = meter.createObservableGauge(`${metricPrefix}_run_time`, {
+  description: 'Run time in seconds', valueType: ValueType.INT
+});
+
+// Base Label Sets
+const attributes = {pid: process.pid, environment: environment};
+
+// Callbacks for Observable Gauges
+concurrencyGauge.addCallback((observableResult) => {
+  workflowIDs.forEach(workflow_id => {
+    customerIDs.forEach(customer_id => {
+      let concurrency = Math.floor(Math.random() * 10) + 1;
+      observableResult.observe(concurrency, {
+        ...attributes, 'workflow_id': workflow_id, 'customer_id': customer_id
+      });
+    });
+  });
+});
+
+cpuUsageGauge.addCallback((observableResult) => {
+  workflowIDs.forEach(workflow_id => {
+    customerIDs.forEach(customer_id => {
+      let cpuUsage = os.loadavg()[0]; // Load average for 1 minute; adjust as needed
+      observableResult.observe(cpuUsage, {
+        ...attributes, 'workflow_id': workflow_id, 'customer_id': customer_id
+      });
+    });
+  });
+});
+
+runInTimeGauge.addCallback((observableResult) => {
+  workflowIDs.forEach(workflow_id => {
+    customerIDs.forEach(customer_id => {
+      let run_time = Math.floor(Math.random() * 60);
+      observableResult.observe(run_time, {
+        ...attributes, 'workflow_id': workflow_id, 'customer_id': customer_id
+      });
+    });
+  });
+});
+
+memoryUsageGauge.addCallback((observableResult) => {
+  workflowIDs.forEach(workflow_id => {
+    customerIDs.forEach(customer_id => {
+      let usedMemory = process.memoryUsage().heapUsed / 1024 / 1024; // Convert bytes to megabytes
+      observableResult.observe(usedMemory, {
+        ...attributes, 'workflow_id': workflow_id, 'customer_id': customer_id, 'unit': 'MB'
+      });
+    });
+  });
+});
+
+
+// Periodically update global variables if needed
+setInterval(() => {
+  console.log("Job Executed")
+}, 15000); // Adjust as needed

docker-compose.yaml

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+version: '3.8'
+services:
+  app:
+    build: .
+    environment:
+      WORKFLOW_ID_COUNT: 100  # Adjust as needed
+      CUSTOMER_ID_COUNT: 40   # Adjust as needed
+      OTLP_ENDPOINT: 'http://localhost:8429/opentelemetry/api/v1/push'
+      SERVICE_NAME: 'custom-metric-service'
+      OTLP_METRIC_EXPORTER_FREQUENCY: 15000
+      OTLP_METER_NAME: 'cms-exporter-collector'
+      ENVIRONMENT: 'staging'