Add metrics instrumentation. I sure hope this works

package.json

@@ -22,7 +22,9 @@
   "dependencies": {
     "@opentelemetry/api": "^1.3.0",
     "@opentelemetry/auto-instrumentations-node": "^0.35.0",
+    "@opentelemetry/exporter-metrics-otlp-grpc": "^0.34.0",
     "@opentelemetry/exporter-trace-otlp-grpc": "^0.34.0",
+    "@opentelemetry/sdk-metrics": "^1.8.0",
     "@opentelemetry/sdk-node": "^0.34.0",
     "@opentelemetry/semantic-conventions": "^1.8.0",
     "@prisma/client": "^4.0.0",

src/index.ts

@@ -5,9 +5,12 @@ import process from 'process';
 import * as dotenv from "dotenv";
 dotenv.config({path: __dirname + '/.env'});
 
+let tracing: any = {};
+
 if (process.env.OPENTELEMETRY_ENABLED === "true") {
     console.log('Enabling OpenTelemetry-compatible tracing...');
-    require('./tracing');
+    tracing = require('./tracing');
+    tracing.startTracing();
 }
 
 import express, { Router } from 'express';
@@ -61,6 +64,29 @@ if (useSentry) {
     });
 }
 
+if (process.env.OPENTELEMETRY_ENABLED === "true") {
+    tracing.startHttpMetrics([
+        {
+            app,
+            options: {
+                appName: 'service'
+            }
+        },
+        {
+            app: muchaApp,
+            options: {
+                appName: 'mucha'
+            }
+        },
+        {
+            app: allnetApp,
+            options: {
+                appName: 'allnet'
+            }
+        }
+    ]);
+}
+
 // Get the current timestamp
 let timestamp: string = common.getTimeStamp();
 

src/tracing.ts

@@ -7,7 +7,11 @@ import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-grpc';
 import { Resource } from '@opentelemetry/resources';
 import { SemanticResourceAttributes } from '@opentelemetry/semantic-conventions';
 import process from 'process';
+import {Request, Response, Application} from 'express';
+import { AggregationTemporality, MeterProvider, PeriodicExportingMetricReader } from '@opentelemetry/sdk-metrics';
+import { OTLPMetricExporter } from '@opentelemetry/exporter-metrics-otlp-grpc';
 
+export function startTracing() {
     diag.setLogger(new DiagConsoleLogger(), DiagLogLevel.INFO);
 
     const sdk = new opentelemetry.NodeSDK({
@@ -24,3 +28,53 @@ const sdk = new opentelemetry.NodeSDK({
     });
     
     sdk.start();
+}
+
+interface MiddlewareOpts {
+    appName: string,
+}
+
+interface HttpMetricsParameter {
+    app: Application,
+    options: MiddlewareOpts
+}
+
+// TODO: Implement stuff in such a way to make it be possible to view data like
+//       time attack clears per hour, story stuff etc etc. Not now tho, later
+export function startHttpMetrics(apps: HttpMetricsParameter[]) {
+    const provider = new MeterProvider();
+    
+    function configureMiddleware(opts: MiddlewareOpts) {
+        let meter = provider.getMeter(opts.appName);
+        var counter = meter.createCounter('requests_made', {
+            description: 'Number of requests registered to application'
+        });
+
+        return function(req: Request, res: Response, next: CallableFunction) {
+            counter.add(1, {
+                url: req.url
+            });
+            next();
+        }
+    }
+
+    console.log('Registering middleware metrics');
+
+    for (let appObj of apps) {
+        console.log(`Registered metrics application for ${appObj.options.appName}`);
+        appObj.app.use(configureMiddleware(appObj.options));
+    }
+
+    const exporter = new OTLPMetricExporter({
+        url: process.env.OPENTELEMETRY_OTLP_URI,
+        temporalityPreference: AggregationTemporality.DELTA,
+    });
+
+    provider.addMetricReader(new PeriodicExportingMetricReader({
+        exporter,
+        exportIntervalMillis: 1500,
+        exportTimeoutMillis: 1000,
+    }));
+
+    console.log('Metrics started');
+}

yarn.lock

@@ -198,6 +198,30 @@
     "@opentelemetry/semantic-conventions" "1.8.0"
     jaeger-client "^3.15.0"
 
+"@opentelemetry/exporter-metrics-otlp-grpc@^0.34.0":
+  version "0.34.0"
+  resolved "https://registry.yarnpkg.com/@opentelemetry/exporter-metrics-otlp-grpc/-/exporter-metrics-otlp-grpc-0.34.0.tgz#3a84f4e2c21ce5c9dce507ff36715cc2536bfa87"
+  integrity sha512-9INc1TBJ7OwpMsImqUjpPEvQeRyyU9tEiFQIYQ53kKQK7V8MqB5koyDeb5/qBSbNu4ZxSpukAOLPgBOEMDK6Qw==
+  dependencies:
+    "@grpc/grpc-js" "^1.7.1"
+    "@opentelemetry/core" "1.8.0"
+    "@opentelemetry/exporter-metrics-otlp-http" "0.34.0"
+    "@opentelemetry/otlp-grpc-exporter-base" "0.34.0"
+    "@opentelemetry/otlp-transformer" "0.34.0"
+    "@opentelemetry/resources" "1.8.0"
+    "@opentelemetry/sdk-metrics" "1.8.0"
+
+"@opentelemetry/exporter-metrics-otlp-http@0.34.0":
+  version "0.34.0"
+  resolved "https://registry.yarnpkg.com/@opentelemetry/exporter-metrics-otlp-http/-/exporter-metrics-otlp-http-0.34.0.tgz#f890a83f695b60719e54492e72bcbfa21d2968ee"
+  integrity sha512-ToRJA4frErHGiKKnPCI3+cvdyK8rksRI+mV6xZ6Yt7HiIrArY9eDX7QaCEZcTLbQIib09LTlCX87TKEL3TToWQ==
+  dependencies:
+    "@opentelemetry/core" "1.8.0"
+    "@opentelemetry/otlp-exporter-base" "0.34.0"
+    "@opentelemetry/otlp-transformer" "0.34.0"
+    "@opentelemetry/resources" "1.8.0"
+    "@opentelemetry/sdk-metrics" "1.8.0"
+
 "@opentelemetry/exporter-trace-otlp-grpc@0.34.0", "@opentelemetry/exporter-trace-otlp-grpc@^0.34.0":
   version "0.34.0"
   resolved "https://registry.yarnpkg.com/@opentelemetry/exporter-trace-otlp-grpc/-/exporter-trace-otlp-grpc-0.34.0.tgz#6ec4a897f263e371f4ce8e3b1aa83167fe6aedc2"
@@ -638,7 +662,7 @@
     "@opentelemetry/core" "1.8.0"
     "@opentelemetry/semantic-conventions" "1.8.0"
 
-"@opentelemetry/sdk-metrics@1.8.0":
+"@opentelemetry/sdk-metrics@1.8.0", "@opentelemetry/sdk-metrics@^1.8.0":
   version "1.8.0"
   resolved "https://registry.yarnpkg.com/@opentelemetry/sdk-metrics/-/sdk-metrics-1.8.0.tgz#d061060f03861ab3f345d0f924922bc1a6396157"
   integrity sha512-+KYb+uj0vHhl8xzJO+oChS4oP1e+/2Wl3SXoHoIdcEjd1TQfDV+lxOm4oqxWq6wykXvI35/JHyejxSoT+qxGmg==