How to Set Up an Endpoint for Health Check on Next.js

Deploying an application on Kubernetes requires it to return a 200 status response to certain routes such as “/healthz” and “/”. While setting up such routes on an Express server is straightforward, it may not be clear how to achieve the same on a frontend application built with Next.js and React.

Solution:

Solution 1: Using an API route in Next.js

To set up a health check endpoint in Next.js, you can create a new file called `healthcheck.js` in the `/pages/api` directory. The file should contain the following code:

export default function handler(req, res) {
  res.status(200).json({ "status": "ok" })
}

This code sets up an API route that returns a JSON response with a status of “ok” and a 200 status code.

Solution 2: Using a different file and URL rewrite

Another option is to create a file called `health.js` in the `/pages/api` directory with the following code:

export default function handler(req, res) {
  res.send('OK');
}

In this case, the response is a simple “OK” string. To handle requests to the `/healthz` URL, you can set up a URL rewrite in the `next.config.js` file:

module.exports = {
  async rewrites() {
    return [
      {
        source: '/healthz',
        destination: '/api/health',
      },
    ]
  },
}

This rewrite rule internally redirects requests from `/healthz` to the `/api/health` API route.

Conclusion:

Setting up an endpoint for health check on Next.js is crucial for ensuring the proper functioning of your application in a Kubernetes environment. By using API routes or URL rewrites, you can easily configure your Next.js application to respond with a 200 status code to the required routes. Follow the solutions provided in this article to set up your health check endpoint and ensure your application’s stability.

How to Set Up an Endpoint for Health Check on Next.js – Next.js