feat(metrics): added collectMetricsExpressMiddleware and deprecated defaultMetricsMiddleware

CHANGELOG.md

@@ -2,6 +2,39 @@
 
 All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
 
+### [5.1.13](https://github.com/MapColonies/telemetry/compare/v5.1.12...v5.1.13) (2023-08-01)
+
+### [5.1.12](https://github.com/MapColonies/telemetry/compare/v5.1.11...v5.1.12) (2023-08-01)
+
+### [5.1.11](https://github.com/MapColonies/telemetry/compare/v5.1.10...v5.1.11) (2023-08-01)
+
+### [5.1.10](https://github.com/MapColonies/telemetry/compare/v5.1.9...v5.1.10) (2023-08-01)
+
+### [5.1.9](https://github.com/MapColonies/telemetry/compare/v5.1.8...v5.1.9) (2023-07-31)
+
+### [5.1.8](https://github.com/MapColonies/telemetry/compare/v5.1.7...v5.1.8) (2023-07-31)
+
+### [5.1.7](https://github.com/MapColonies/telemetry/compare/v5.1.5...v5.1.7) (2023-07-31)
+
+### [5.1.5](https://github.com/MapColonies/telemetry/compare/v5.1.4...v5.1.5) (2023-07-31)
+
+### [5.1.4](https://github.com/MapColonies/telemetry/compare/v5.1.3...v5.1.4) (2023-07-31)
+
+### [5.1.3](https://github.com/MapColonies/telemetry/compare/v5.1.2...v5.1.3) (2023-07-31)
+
+### [5.1.2](https://github.com/MapColonies/telemetry/compare/v5.1.1...v5.1.2) (2023-07-31)
+
+### [5.1.1](https://github.com/MapColonies/telemetry/compare/v5.1.0...v5.1.1) (2023-07-31)
+
+## [5.1.0](https://github.com/MapColonies/telemetry/compare/v5.0.0...v5.1.0) (2023-07-31)
+
+
+### Features
+
+* added defaultLabels ([ca565a5](https://github.com/MapColonies/telemetry/commit/ca565a5ba1a83667e3cbd2623e0a4a174347f3e1))
+* collectMetricsExpressMiddleware ([8f8001f](https://github.com/MapColonies/telemetry/commit/8f8001fa4cb46dfc5e87667115859b3a78f5c3a1))
+* **metrics:** added collectMetricsExpressMiddleware and deprecated defaultMetricsMiddleware ([5604cc3](https://github.com/MapColonies/telemetry/commit/5604cc3350076c0659e72b3251fdda1d184670be))
+
 ## [5.0.0](https://github.com/MapColonies/telemetry/compare/v4.2.0...v5.0.0) (2023-07-07)
 
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@map-colonies/telemetry",
-  "version": "5.0.0",
+  "version": "5.1.13",
   "description": "Package for everything opentelemetry related in map colonies",
   "main": "./dist/index.js",
   "scripts": {
@@ -47,6 +47,7 @@
     "@opentelemetry/sdk-trace-base": "^1.14.0",
     "@opentelemetry/sdk-trace-node": "^1.14.0",
     "env-var": "^7.1.1",
+    "express-prom-bundle": "^6.6.0",
     "prom-client": "^14.2.0"
   },
   "devDependencies": {

src/metrics/index.ts

@@ -1,3 +1,2 @@
 export { Metrics } from './metrics';
-export { defaultMetricsMiddleware } from './middleware/defaultMetrics';
-export { metricsMiddleware } from './middleware/metrics';
+export { defaultMetricsMiddleware, collectMetricsExpressMiddleware } from './middleware/metrics';

src/metrics/middleware/metrics.ts

@@ -1,5 +1,30 @@
-import { Registry, collectDefaultMetrics } from 'prom-client';
+import { hostname as osHostname } from 'os';
+import { Registry, collectDefaultMetrics, Gauge, register } from 'prom-client';
+import * as promBundle from 'express-prom-bundle';
 import * as express from 'express';
+import { loadPackageInfo } from '../../common/packageInfoLoader';
+
+const deconstructSemver = (semverString: string): { major: string; minor: string; patch: string; prerelease: string; build: string } | null => {
+  const match = /^(\d+)(?:\.(\d+))?(?:\.(\d+))?(?:-([\w-]+))?(?:\+([\w-]+))?/i.exec(semverString);
+  if (!match) {
+    return null;
+  }
+  return {
+    major: match[1],
+    minor: match[2],
+    patch: match[3],
+    prerelease: match[4],
+    build: match[5],
+  };
+};
+
+interface Opts {
+  registry: Registry;
+  collectNodeMetrics: boolean;
+  collectServiceVersion: boolean;
+  prefix: string;
+  labels: Record<string, string>;
+}
 
 export function metricsMiddleware(
   registry: Registry,
@@ -19,3 +44,78 @@ export function metricsMiddleware(
     }
   };
 }
+
+/**
+ * @deprecated since version v5.1, please use collectMetricsExpressMiddleware
+ */
+export function defaultMetricsMiddleware(prefix?: string, labels?: Record<string, string>): express.RequestHandler {
+  const register = new Registry();
+  collectDefaultMetrics({ prefix, register, labels });
+  return async (req: express.Request, res: express.Response, next: express.NextFunction): Promise<void> => {
+    try {
+      res.set('Content-Type', register.contentType);
+      res.end(await register.metrics());
+    } catch (error) {
+      return next(error);
+    }
+  };
+}
+
+export function collectMetricsExpressMiddleware(options: Partial<Opts>): promBundle.Middleware {
+  const pacakgeInfo = loadPackageInfo();
+  const defaultOpts: Opts = {
+    prefix: '',
+    labels: {},
+    collectNodeMetrics: true,
+    collectServiceVersion: true,
+    registry: new Registry(),
+  };
+  const meregedOptions = { ...defaultOpts, ...options };
+  /* eslint-disable @typescript-eslint/naming-convention */
+  const mergedLabels = {
+    hostname: osHostname(),
+    service_name: pacakgeInfo.name,
+    ...(options.labels ? options.labels : {}),
+  };
+  register.setDefaultLabels(mergedLabels);
+  if (meregedOptions.collectNodeMetrics) {
+    collectDefaultMetrics({ prefix: meregedOptions.prefix, labels: mergedLabels, register: meregedOptions.registry });
+  }
+
+  if (meregedOptions.collectServiceVersion) {
+    const gaugeLabels = ['service_version_major', 'service_version_minor', 'service_version_patch', 'service_version_prerelease'];
+    const semver = deconstructSemver(pacakgeInfo.version);
+    if (!semver) {
+      throw new Error('package.json includes version not according to semver spec');
+    }
+    const { major, minor, patch, prerelease } = semver;
+    const serviceVersionGauge = new Gauge({
+      name: `${meregedOptions.prefix ? `${meregedOptions.prefix}_` : ''}service_version`,
+      help: 'Service Version Specified in package.json file',
+      labelNames: gaugeLabels,
+      registers: [meregedOptions.registry],
+    });
+    /* eslint-disable @typescript-eslint/naming-convention */
+    serviceVersionGauge.set(
+      {
+        ...mergedLabels,
+        service_version_major: major,
+        service_version_minor: minor,
+        service_version_patch: patch,
+        service_version_prerelease: prerelease,
+      },
+      1
+    );
+  }
+
+  const promBundleConfig: promBundle.Opts = {
+    promRegistry: meregedOptions.registry,
+    autoregister: true,
+    includeUp: true,
+    customLabels: mergedLabels,
+    includeMethod: true,
+    includeStatusCode: true,
+    includePath: true,
+  };
+  return promBundle(promBundleConfig);
+}

tsconfig.json

@@ -1,6 +1,6 @@
 {
   "compilerOptions": {
-    "target": "es5",
+    "target": "ES2022",
     "allowSyntheticDefaultImports": true,
     "strict": true,
     "module": "commonjs",