fastify-health-check

fastify-health-check is a lightweight plugin for Fastify that provides an endpoint for health checks. It's configurable and can be used to monitor the health of your service easily.

Features

• Liveness and readiness endpoints: Separate routes to handle liveness and readiness checks
• Custom readiness checks: Implement custom logic to determine service readiness
• Configurable routes: Easily configure the routes for health checks

Install

npm install fastify-health-check

Or using yarn:

yarn add fastify-health-check

Usage

Register the plugin with your Fastify instance:

const fastify = require('fastify')();
const fastifyHealthCheck = require('fastify-health-check');

fastify.register(fastifyHealthCheck, {
  enableLiveness: true, // Defaults: True
  livenessRoute: "/health",
  enableReadiness: true, // Defaults: True
  readinessRoute: "/readiness",
  readinessCheckFn: (request: FastifyRequest) => {
    return {
      version: request.server.version,
      timestamp: new Date().toISOString(),
    };
  },
});

fastify.listen(3000, (err) => {
  if (err) {
    fastify.log.error(err);
    process.exit(1);
  }
  fastify.log.info('Server listening on http://localhost:3000');
});

Options

• enableLiveness (boolean, default: true): Enable or disable the liveness check route.
• livenessRoute (string, default: /health): The endpoint path for the liveness check.
• enableReadiness (boolean, default: true): Enable or disable the readiness check route.
• readinessRoute (string, default: /readiness): The endpoint path for the readiness check.
• readinessCheckFn (function, optional): A custom function that performs readiness checks. This function can use the Fastify request object to return custom information about the service readiness.

Example

Here is an example of a more advanced health check:

const fastify = require('fastify')();
const fastifyHealthCheck = require('fastify-health-check');

fastify.register(fastifyHealthCheck, {
  enableLiveness: true,
  livenessRoute: '/health',
  enableReadiness: true,
  readinessRoute: '/readiness',
  readinessCheckFn: (request) => {
    return {
      version: request.server.version,
      timestamp: new Date().toISOString(),
    };
  },
});

fastify.listen(3000, (err) => {
  if (err) {
    fastify.log.error(err);
    process.exit(1);
  }
  fastify.log.info('Server is up and running at http://localhost:3000');
});

In this example, the liveness check is available at /health, and the readiness check is available at /readiness. The readiness check also includes a custom function that returns the server version and the current timestamp

Test

To run the tests:

npm test

License

Licensed under the MIT License.

Acknowledgements

This plugin was inspired by the need for a simple and effective way to monitor Fastify services