@qrvey/health-checker

An health check library for validating the availability of core service dependencies like Redis, PostgreSQL, and RabbitMQ.

Installation

npm install @qrvey/health-checker

Or with yarn:

yarn add @qrvey/health-checker

Supported Health Check Types

Service	Dependency Key
PostgreSQL	database
Redis	cache
RabbitMQ	eventBroker

Usage

const {
  HealthCheckService,
} = require('@qrvey/health-checker');


HealthCheckService.check(['cache', 'database', 'eventBroker']).then((result) => {
  console.log(result);
  /*
  {
    status: 'OK',
    details: {
      cache: 'OK',
      database: 'OK',
      eventBroker: 'OK'
    }
  }
  */
});

You can also check specific dependencies only:

HealthCheckService.check(['cache']).then((result) => {
  console.log(result);
  /*
  {
    status: 'OK',
    details: {
      cache: 'OK'
    }
  }
  */
});

Usage with Fastify

You can expose the health check as a simple route in your Fastify app.

Basic Example: health.routes.js

const {
  HealthCheckService,
} = require('@qrvey/health-checker');
const Fastify = require('fastify');

async function healthRoutes(fastify, _options) {
  fastify.get('/health', async (_request, reply) => {
    const dependencies = ['database', 'eventBroker'];
    const result = await HealthCheckService.check(dependencies);
    const httpStatus = result.status === "FAILED" ? 503 : 200;
    return reply.code(httpStatus).send(result);
  });
}

const app = Fastify({ logger: true });
app.register(healthRoutes);
app.listen({ port: 3000 });

Basic Example Output

GET /health

{
  "status": "OK",
  "details": {
    "database": "OK",
    "eventBroker": "OK"
  }
}

Validating Queue Subscriptions (Optional)

If you want to explicitly validate that your service is subscribed to one or more RabbitMQ queues, you can pass an additional params object to the check method.

fastify.get('/health', async (_request, reply) => {
  const dependencies = ['eventBroker'];
  const params = {
    eventBroker: {
      queues: ['queue_name_1', 'queue_name_2'], // these must match the configured subscriptions
    },
  }

  const result = await HealthCheckService.check(dependencies, params);
  const httpStatus = result.status === "FAILED" ? 503 : 200;
  return reply.code(httpStatus).send(result);
});

Sample output

GET /health

{
  "status": "OK",
  "details": {
    "eventBroker": "OK"
  }
}