Implement health check

.dockerignore

@@ -0,0 +1 @@
+node_modules

Dockerfile

@@ -25,4 +25,6 @@ COPY . .
 
 COPY --from=development /usr/src/app/dist ./dist
 
+HEALTHCHECK CMD curl -f http://localhost:3000/health || exit 1
+
 CMD ["node", "dist/main"]

docker-compose.yml

@@ -8,12 +8,13 @@ services:
       target: development
     volumes:
       - .:/usr/src/app
-      - /usr/src/app/node_modules
     ports:
       - 3000:3000
     command: yarn start:dev
     env_file:
       - .env
+    healthcheck:
+      test: ['CMD', 'curl', '-f', 'http://localhost:3000/health']
     depends_on:
       - mongo
   mongo:

package.json

@@ -27,6 +27,7 @@
     "@nestjs/mongoose": "^7.2.3",
     "@nestjs/platform-express": "^7.5.1",
     "@nestjs/schedule": "^0.4.2",
+    "@nestjs/terminus": "^7.1.0",
     "cache-manager": "^3.4.0",
     "date-fns": "^2.17.0",
     "joi": "^17.4.0",

src/app.module.ts

@@ -10,6 +10,7 @@ import { AppService } from './app.service';
 import { CitiesModule } from './cities/cities.module';
 import { ForecastModule } from './forecast/forecast.module';
 import { SchedulerModule } from './scheduler/scheduler.module';
+import { HealthModule } from './health/health.module';
 
 @Module({
   imports: [
@@ -31,6 +32,7 @@ import { SchedulerModule } from './scheduler/scheduler.module';
     CitiesModule,
     ForecastModule,
     SchedulerModule,
+    HealthModule,
   ],
   controllers: [AppController],
   providers: [AppService],

src/config/configuration.ts

@@ -1,6 +1,6 @@
 export const configuration = () => ({
   forecastAPI: {
-    uri: process.env.API_URL,
+    url: process.env.API_URL,
     key: process.env.API_KEY,
   },
   database: {

src/forecast/forecast.service.ts

@@ -24,15 +24,15 @@ interface IForecast {
 
 @Injectable()
 export class ForecastService {
-  private readonly url = this.configService.get<string>('forecastAPI.url');
-  private readonly key = this.configService.get<string>('forecastAPI.key');
-
   constructor(
     private configService: ConfigService,
     private httpService: HttpService,
     @InjectModel(Forecast.name) private forecastModel: Model<ForecastDocument>,
   ) {}
 
+  private readonly url = this.configService.get<string>('forecastAPI.url');
+  private readonly key = this.configService.get<string>('forecastAPI.key');
+
   async fetchForecast({ name, country }: CityDocument) {
     try {
       const { data } = await this.httpService

src/health/health.controller.ts

@@ -0,0 +1,36 @@
+import { Controller, Get } from '@nestjs/common';
+import {
+  HealthCheck,
+  HealthCheckService,
+  HttpHealthIndicator,
+  MongooseHealthIndicator,
+} from '@nestjs/terminus';
+import { ConfigService } from '@nestjs/config';
+
+@Controller('health')
+export class HealthController {
+  constructor(
+    private configService: ConfigService,
+    private health: HealthCheckService,
+    private http: HttpHealthIndicator,
+    private mongoose: MongooseHealthIndicator,
+  ) {}
+
+  private readonly url = this.configService.get<string>('forecastAPI.url');
+  private readonly key = this.configService.get<string>('forecastAPI.key');
+
+  @Get()
+  @HealthCheck()
+  check() {
+    return this.health.check([
+      async () =>
+        this.http.pingCheck('openweathermap-api', this.url, {
+          params: {
+            q: `Helsinki,FI`,
+            appid: this.key,
+          },
+        }),
+      async () => this.mongoose.pingCheck('mongoose'),
+    ]);
+  }
+}

src/health/health.module.ts

@@ -0,0 +1,10 @@
+import { Module } from '@nestjs/common';
+import { TerminusModule } from '@nestjs/terminus';
+
+import { HealthController } from './health.controller';
+
+@Module({
+  imports: [TerminusModule],
+  controllers: [HealthController],
+})
+export class HealthModule {}

src/main.ts

@@ -3,6 +3,10 @@ import { AppModule } from './app.module';
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
+
+  // Starts listening for shutdown hooks
+  app.enableShutdownHooks();
+
   await app.listen(3000);
 }
 bootstrap();

yarn.lock

@@ -650,6 +650,14 @@
     fs-extra "9.1.0"
     pluralize "8.0.0"
 
+"@nestjs/terminus@^7.1.0":
+  version "7.1.0"
+  resolved "https://registry.yarnpkg.com/@nestjs/terminus/-/terminus-7.1.0.tgz#fa9666e903a405541fe431a709690b678a24d8cb"
+  integrity sha512-5C6ZpC7DU9HunPmRwYZVK/DiQaNjQfH/KiDMKBLzWTiVG5cVaV+II5eTr0cdhmaaJk58u54S/5eb7lGaK5MGHQ==
+  dependencies:
+    check-disk-space "2.1.0"
+    deprecate "^1.1.1"
+
 "@nestjs/testing@^7.6.13":
   version "7.6.13"
   resolved "https://registry.yarnpkg.com/@nestjs/testing/-/testing-7.6.13.tgz#a0cd208fb541aa9084eb55cdd120d1e67eec49c1"
@@ -1786,6 +1794,11 @@ chardet@^0.7.0:
   resolved "https://registry.yarnpkg.com/chardet/-/chardet-0.7.0.tgz#90094849f0937f2eedc2425d0d28a9e5f0cbad9e"
   integrity sha512-mT8iDcrh03qDGRRmoA2hmBJnxpllMR+0/0qlzjqZES6NdiWDcZkCNAk4rPFZ9Q85r27unkiNNg8ZOiwZXBHwcA==
 
+check-disk-space@2.1.0:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/check-disk-space/-/check-disk-space-2.1.0.tgz#2e77fe62f30d9676dc37a524ea2008f40c780295"
+  integrity sha512-f0nx9oJF/AVF8nhSYlF1EBvMNnO+CXyLwKhPvN1943iOMI9TWhQigLZm80jAf0wzQhwKkzA8XXjyvuVUeGGcVQ==
+
 chokidar@3.5.1, chokidar@^3.4.2:
   version "3.5.1"
   resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-3.5.1.tgz#ee9ce7bbebd2b79f49f304799d5468e31e14e68a"
@@ -2186,6 +2199,11 @@ depd@~1.1.2:
   resolved "https://registry.yarnpkg.com/depd/-/depd-1.1.2.tgz#9bcd52e14c097763e749b274c4346ed2e560b5a9"
   integrity sha1-m81S4UwJd2PnSbJ0xDRu0uVgtak=
 
+deprecate@^1.1.1:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/deprecate/-/deprecate-1.1.1.tgz#4632e981fc815eeaf00be945a40359c0f8bf9913"
+  integrity sha512-ZGDXefq1xknT292LnorMY5s8UVU08/WKdzDZCUT6t9JzsiMSP4uzUhgpqugffNVcT5WC6wMBiSQ+LFjlv3v7iQ==
+
 destroy@~1.0.4:
   version "1.0.4"
   resolved "https://registry.yarnpkg.com/destroy/-/destroy-1.0.4.tgz#978857442c44749e4206613e37946205826abd80"