Adding prometheus

src/app.module.ts

@@ -13,6 +13,7 @@ import { DatabaseLoggerService } from './logger/service.database_logger'
 import { MembersModule } from './members/module'
 import { MonitoringModule } from './monitoring/module'
 import { NtfyModule } from './ntfy/module'
+import { PrometheusModule } from './prometheus/module'
 import { RecurringReservationsModule } from './recurringReservations/module'
 import { ReservationsModule } from './reservations/module'
 import { RunnerModule } from './runner/module'
@@ -63,6 +64,7 @@ import { WaitingListModule } from './waitingList/module'
 		WaitingListModule,
 		NtfyModule,
 		MonitoringModule,
+		PrometheusModule,
 	],
 })
 export class AppModule implements NestModule {

src/prometheus/module.ts

@@ -0,0 +1,8 @@
+import { Module } from '@nestjs/common'
+
+import { PrometheusProvider } from './provider'
+
+@Module({
+	providers: [PrometheusProvider],
+})
+export class PrometheusModule {}

src/prometheus/provider.ts

@@ -0,0 +1,18 @@
+import { OnApplicationBootstrap } from '@nestjs/common'
+import { collectDefaultMetrics, Registry } from 'prom-client'
+
+export class PrometheusProvider implements OnApplicationBootstrap {
+	private readonly registry: Registry
+
+	constructor() {
+		this.registry = new Registry()
+	}
+
+	onApplicationBootstrap() {
+		collectDefaultMetrics({
+			register: this.registry,
+			prefix: 'autobaan_',
+			labels: { GIT_COMMIT: process.env.GIT_COMMIT ?? 'unknown' },
+		})
+	}
+}