Feature/liveness probe (#8037)

* Setup liveness probe endpoint

* Update documentation

* Update changelog

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+### Added
+
+- Extended the _Public API_ with the liveness probe endpoint (`GET api/v1/health/liveness`) (experimental)
+
 ### Changed
 
 - Upgraded `@simplewebauthn/browser` and `@simplewebauthn/server` from version `13.3` to `14.0`

README.md

@@ -193,6 +193,8 @@ You can get the _Bearer Token_ via `POST http://localhost:3333/api/v1/auth/anony
 
 ### Health Check (experimental)
 
+The endpoint checks the connection to the database and to _Redis_. It is suitable as the readiness probe of an orchestrator (e.g. `readinessProbe` in _Kubernetes_) and as the `healthcheck` in _Docker Compose_. The check of _Redis_ can take up to 5 seconds. Thus, set the timeout of the probe to at least 5 seconds (e.g. `timeoutSeconds: 5` in _Kubernetes_).
+
 #### Request
 
 `GET http://localhost:3333/api/v1/health`
@@ -211,6 +213,28 @@ You can get the _Bearer Token_ via `POST http://localhost:3333/api/v1/auth/anony
 }
 ```
 
+### Liveness Probe (experimental)
+
+The endpoint answers without a check of the database or _Redis_. It is suitable as the liveness probe of an orchestrator (e.g. `livenessProbe` in _Kubernetes_), so that an outage of a dependency after the start does not restart the container. The database migrations run before the server starts. Thus, also use the endpoint as the startup probe (e.g. `startupProbe` in _Kubernetes_), so that a long migration does not restart the container.
+
+#### Request
+
+`GET http://localhost:3333/api/v1/health/liveness`
+
+**Info:** No Bearer Token is required for liveness probe
+
+#### Response
+
+##### Success
+
+`200 OK`
+
+```
+{
+  "status": "OK"
+}
+```
+
 ### Import Portfolio Data
 
 #### Prerequisites

apps/api/src/app/health/health.controller.ts

@@ -3,7 +3,8 @@ import { TransformDataSourceInRequestInterceptor } from '@ghostfolio/api/interce
 import {
   AiServiceHealthResponse,
   DataEnhancerHealthResponse,
-  DataProviderHealthResponse
+  DataProviderHealthResponse,
+  LivenessHealthResponse
 } from '@ghostfolio/common/interfaces';
 
 import {
@@ -33,9 +34,11 @@ export class HealthController {
 
   @Get()
   public async getHealth(@Res() response: Response) {
-    const databaseServiceHealthy = await this.healthService.isDatabaseHealthy();
-    const redisCacheServiceHealthy =
-      await this.healthService.isRedisCacheHealthy();
+    const [databaseServiceHealthy, redisCacheServiceHealthy] =
+      await Promise.all([
+        this.healthService.isDatabaseHealthy(),
+        this.healthService.isRedisCacheHealthy()
+      ]);
 
     if (databaseServiceHealthy && redisCacheServiceHealthy) {
       return response
@@ -116,4 +119,9 @@ export class HealthController {
         .json({ status: getReasonPhrase(StatusCodes.SERVICE_UNAVAILABLE) });
     }
   }
+
+  @Get('liveness')
+  public getLiveness(): LivenessHealthResponse {
+    return { status: getReasonPhrase(StatusCodes.OK) };
+  }
 }

libs/common/src/lib/interfaces/index.ts

@@ -68,6 +68,7 @@ import type { ExportResponse } from './responses/export-response.interface';
 import type { HistoricalResponse } from './responses/historical-response.interface';
 import type { ImportResponse } from './responses/import-response.interface';
 import type { InfoResponse } from './responses/info-response.interface';
+import type { LivenessHealthResponse } from './responses/liveness-health-response.interface';
 import type { LookupResponse } from './responses/lookup-response.interface';
 import type { MarketDataOfMarketsResponse } from './responses/market-data-of-markets-response.interface';
 import type { OAuthResponse } from './responses/oauth-response.interface';
@@ -156,6 +157,7 @@ export {
   InfoResponse,
   InvestmentItem,
   LineChartItem,
+  LivenessHealthResponse,
   LookupItem,
   LookupResponse,
   MarketData,

libs/common/src/lib/interfaces/responses/liveness-health-response.interface.ts

@@ -0,0 +1,3 @@
+export interface LivenessHealthResponse {
+  status: string;
+}