@lcdev/health-check v0.1.9

Launchcode Health Check

Common health check route for services. This is a thin wrapper over maikai. We use it for kubernetes health checking.

yarn add @lcdev/health-check@VERSION

This module assumes that you're using a koa server.

Use it simply by using the middleware. Be careful to not guard it under authentication.

import { createHealthEndpoint, createSystemHealthEndpoint } from '@lcdev/health-check';

// kubernetes compliant health check on /health
app.use(createHealthEndpoint());

// more specific health checking on /system-health
// you might want this to be locked down by authentication to avoid leaking system details
app.use(createSystemHealthEndpoint());

The createHealthEndpoint middleware accepts (path: string), (checks: Check[]) or (path: string, checks: Check[]). You probably want to include other aspects of your system for a health check. For example, here's checking a database and redis connection.

// assuming 'knex' and 'redis' are variables
app.use(
  createHealthEndpoint([
    {
      component: 'postgres',
      metric: 'alive',
      async check() {
        return knex
          .raw('select 1')
          .then(() => ({ status: 'pass' }))
          .catch(() => ({ status: 'fail' }));
      },
    },
    {
      component: 'redis',
      metric: 'alive',
      async check() {
        return redis
          .echo('ping')
          .then(() => ({ status: 'pass' }))
          .catch(() => ({ status: 'fail' }));
      },
    },
  ]),
);