health-checks.md

Usage

1, install the required package:

$ npm install --save @nestjs/terminus

2, import TerminusModule and RedisHealthModule into the imports array:

// app.module.ts
import { Module } from '@nestjs/common';
import { TerminusModule } from '@nestjs/terminus';
import { RedisModule } from '@indiebase/nestjs-redis';
import { RedisHealthModule } from '@indiebase/nestjs-redis/health';
import { AppController } from './app.controller';

@Module({
  imports: [
    RedisModule.forRoot({
      readyLog: true,
      config: {
        host: 'localhost',
        port: 6380,
        password: 'redismain'
      }
    }),
    TerminusModule,
    RedisHealthModule
  ],
  controllers: [AppController]
})
export class AppModule {}

INFO: Read more about @nestjs/terminus here.

HINT: Neither TerminusModule nor RedisHealthModule is global module.

3, let's setup AppController:

// app.controller.ts
import { Controller, Get } from '@nestjs/common';
import { HealthCheckService, HealthCheck, HealthCheckResult } from '@nestjs/terminus';
import { InjectRedis } from '@indiebase/nestjs-redis';
import { RedisHealthIndicator } from '@indiebase/nestjs-redis/health';
import Redis from 'ioredis';

@Controller()
export class AppController {
  constructor(
    private readonly health: HealthCheckService,
    private readonly redisIndicator: RedisHealthIndicator,
    @InjectRedis() private readonly redis: Redis
  ) {}

  @Get('health')
  @HealthCheck()
  async healthChecks(): Promise<HealthCheckResult> {
    return await this.health.check([
      () => this.redisIndicator.checkHealth('redis', { type: 'redis', client: this.redis, timeout: 500 })
    ]);
  }
}

4, if your redis server is reachable, you should now see the following JSON-result when requesting http://localhost:3000/health with a GET request:

{
  "status": "ok",
  "info": {
    "redis": {
      "status": "up"
    }
  },
  "error": {},
  "details": {
    "redis": {
      "status": "up"
    }
  }
}

Settings

Redis

Name	Type	Default	Required	Description
type	'redis'	undefined	true	Server type. You must specify what Redis server type you use. Possible values are "redis", "cluster".
client	Redis	undefined	true	The client which the health check should get executed.
timeout	number	1000	false	The amount of time the check should require in ms.
memoryThreshold	number	undefined	false	The maximum amount of memory used by redis in bytes.

Cluster

Name	Type	Default	Required	Description
type	'cluster'	undefined	true	Server type. You must specify what Redis server type you use. Possible values are "redis", "cluster".
client	Cluster	undefined	true	The client which the health check should get executed.