Merge pull request #4 from openfoodfacts:line-endings

Health check

.gitattributes

@@ -0,0 +1,4 @@
+* text=auto eol=lf
+[core]
+    # avoid line ending conversion on windows
+    autocrlf=false

package.json

@@ -31,6 +31,7 @@
     "@nestjs/common": "^9.0.0",
     "@nestjs/core": "^9.0.0",
     "@nestjs/platform-express": "^9.0.0",
+    "@nestjs/terminus": "^10.1.1",
     "id128": "^1.6.6",
     "mongodb": "^5.8.0",
     "reflect-metadata": "^0.1.13",

src/app.module.ts

@@ -1,9 +1,10 @@
 import { Module } from '@nestjs/common';
 import { AppController } from './app.controller';
 import { DomainModule } from './domain/domain.module';
+import { HealthModule } from './health/health.module';
 
 @Module({
-  imports: [DomainModule],
+  imports: [DomainModule, HealthModule],
   controllers: [AppController],
   providers: [],
 })

src/health/health.controller.spec.ts

@@ -0,0 +1,48 @@
+import { HealthController } from './health.controller';
+import { createTestingModule } from '../../test/test.helper';
+import { AppModule } from '../app.module';
+import { MongodbHealthIndicator } from './mongodb-health-indicator';
+import { HealthCheckError, HealthIndicatorResult } from '@nestjs/terminus';
+import { ServiceUnavailableException } from '@nestjs/common';
+
+describe('HealthController', () => {
+  it('should return healthy', async () => {
+    await createTestingModule([AppModule], async (app) => {
+      const controller = app.get(HealthController);
+      expect(controller).toBeDefined();
+
+      const mongoIndicator = app.get(MongodbHealthIndicator);
+      mongoIndicator.isHealthy = jest.fn(async () => {
+        return {
+          mongodb: {
+            status: 'up',
+          },
+        } as HealthIndicatorResult;
+      });
+      const status = await controller.check();
+      expect(status.status).toBe('ok');
+    });
+  });
+
+  it('should return unhealthy if mongodb is down', async () => {
+    await createTestingModule([AppModule], async (app) => {
+      const controller = app.get(HealthController);
+
+      const mongoIndicator = app.get(MongodbHealthIndicator);
+      mongoIndicator.isHealthy = jest.fn(async () => {
+        throw new HealthCheckError('Mongodb check failed', {
+          mongodb: {
+            status: 'down',
+          },
+        });
+      });
+      try {
+        await controller.check();
+        fail('should not get here');
+      } catch (e) {
+        expect(e).toBeInstanceOf(ServiceUnavailableException);
+        expect(e.response.status).toBe('error');
+      }
+    });
+  });
+});

src/health/health.controller.ts

@@ -0,0 +1,22 @@
+import { Controller, Get } from '@nestjs/common';
+import { HealthCheckService, HealthCheck } from '@nestjs/terminus';
+import { PostgresHealthIndicator } from './postgres-health-indicator';
+import { MongodbHealthIndicator } from './mongodb-health-indicator';
+
+@Controller('health')
+export class HealthController {
+  constructor(
+    private health: HealthCheckService,
+    private postgres: PostgresHealthIndicator,
+    private mongodb: MongodbHealthIndicator,
+  ) {}
+
+  @Get()
+  @HealthCheck()
+  check() {
+    return this.health.check([
+      () => this.postgres.isHealthy(),
+      () => this.mongodb.isHealthy(),
+    ]);
+  }
+}

src/health/health.module.ts

@@ -0,0 +1,13 @@
+import { Module } from '@nestjs/common';
+import { HealthController } from './health.controller';
+import { PostgresHealthIndicator } from './postgres-health-indicator';
+import { TerminusModule } from '@nestjs/terminus';
+import { DomainModule } from '../domain/domain.module';
+import { MongodbHealthIndicator } from './mongodb-health-indicator';
+
+@Module({
+  imports: [TerminusModule, DomainModule],
+  controllers: [HealthController],
+  providers: [PostgresHealthIndicator, MongodbHealthIndicator],
+})
+export class HealthModule {}

src/health/mongodb-health-indicator.ts

@@ -0,0 +1,35 @@
+import { Injectable } from '@nestjs/common';
+import {
+  HealthIndicator,
+  HealthIndicatorResult,
+  HealthCheckError,
+} from '@nestjs/terminus';
+import { MongoClient } from 'mongodb';
+
+@Injectable()
+export class MongodbHealthIndicator extends HealthIndicator {
+  NAME = 'mongodb';
+  async isHealthy(): Promise<HealthIndicatorResult> {
+    try {
+      const client = new MongoClient(process.env.MONGO_URI, {
+        serverSelectionTimeoutMS: 1000,
+        connectTimeoutMS: 1000,
+        socketTimeoutMS: 1000,
+      });
+      await client.connect();
+      const db = client.db('off');
+      const products = db.collection('products');
+      const cursor = products.find({}, { projection: { code: 1 } });
+      await cursor.next();
+      await cursor.close();
+      await client.close();
+
+      return this.getStatus(this.NAME, true);
+    } catch (e) {
+      throw new HealthCheckError(
+        'MongoDB check failed',
+        this.getStatus(this.NAME, false, e),
+      );
+    }
+  }
+}