How to Change Environment Variable Values at Runtime in NEXT.JS without having to Rebuild the Project Again

Environment variables, those mystical creatures that hold the secrets of our application’s configuration. We set them, we forget them, and then we scratch our heads wondering why our app isn’t working as expected. But what if I told you there’s a way to change environment variable values at runtime in NEXT.JS without having to rebuild the project again? Yes, you read that right! No more tedious rebuilding, no more pulling your hair out in frustration. In this article, we’ll explore the magic behind dynamic environment variables and guide you through the process of changing them at runtime.

What are Environment Variables?

Before we dive into the good stuff, let’s quickly recap what environment variables are. Environment variables are values that are set outside of your application’s code, but are used within it. They can store anything from API keys to database connections, and are usually stored in a `.env` file. In NEXT.JS, you can set environment variables using the `next.config.js` file.

Why Do We Need to Change Environment Variable Values at Runtime?

There are several scenarios where changing environment variable values at runtime becomes necessary. Here are a few examples:

• Staging vs. Production: You might want to use different API keys or database connections for staging and production environments.
• Feature Flagging: Imagine you want to enable or disable a feature based on user roles or permissions.
• Dynamic Configuration: Your application might require dynamic configuration based on user input or external factors.

The Problem with NEXT.JS Environment Variables

In NEXT.JS, environment variables are set at build time, which means that once your project is built, the environment variables are baked into the code. This makes it difficult to change them at runtime without rebuilding the project.

The Solution: Using a Configuration Service

To change environment variable values at runtime, we’ll create a configuration service that will act as a middleware between our application and the environment variables. This service will allow us to update environment variables dynamically without requiring a rebuild.

// config.service.js
import axios from 'axios';

const configService = {
  getConfig: async () => {
    const response = await axios.get('/api/config');
    return response.data;
  },
  updateConfig: async (newConfig) => {
    await axios.post('/api/config', newConfig);
  }
};

export default configService;

Creating an API to Update Environment Variables

We’ll create an API endpoint that will update the environment variables in our configuration service. This endpoint will be called by our application whenever we need to update the environment variables.

// pages/api/config.js
import { NextApiRequest, NextApiResponse } from 'next';
import configService from '../config.service';

const updateConfig = async (req: NextApiRequest, res: NextApiResponse) => {
  if (req.method === 'POST') {
    const newConfig = req.body;
    await configService.updateConfig(newConfig);
    return res.status(200).json({ message: 'Config updated successfully' });
  } else {
    return res.status(405).json({ message: 'Method not allowed' });
  }
};

export default updateConfig;

Using the Configuration Service in Your NEXT.JS Application

Now that we have our configuration service and API endpoint set up, let’s use them in our NEXT.JS application. We’ll create a hook that will fetch the environment variables from the configuration service and update them whenever necessary.

// use-config.js
import { useState, useEffect } from 'react';
import configService from '../config.service';

const useConfig = () => {
  const [config, setConfig] = useState({});

  useEffect(() => {
    const fetchConfig = async () => {
      const config = await configService.getConfig();
      setConfig(config);
    };
    fetchConfig();
  }, []);

  const updateConfig = async (newConfig) => {
    await configService.updateConfig(newConfig);
    setConfig(newConfig);
  };

  return { config, updateConfig };
};

export default useConfig;

Example Usage

Let’s say we want to use the `useConfig` hook to fetch and update the environment variables in our application.

// pages/index.js
import useConfig from '../use-config';

const IndexPage = () => {
  const { config, updateConfig } = useConfig();

  const handleUpdateConfig = async () => {
    const newConfig = { API_KEY: 'new-api-key' };
    await updateConfig(newConfig);
  };

  return (
    

      
      Update API Key
    
  );
};

export default IndexPage;

Conclusion

Changing environment variable values at runtime in NEXT.JS without having to rebuild the project again is definitely possible. By using a configuration service and an API endpoint, we can update environment variables dynamically and make our application more flexible and adaptable to changing requirements.

Benefits

Using this approach has several benefits, including:

• Dynamic configuration: Update environment variables at runtime without requiring a rebuild.
• Faster development: No more rebuilding the project every time you need to change an environment variable.
• Easier maintenance: Update environment variables in a centralized location, making it easier to manage your application’s configuration.

Best Practices

When using this approach, keep the following best practices in mind:

• Use a secure API endpoint to update environment variables.
• Validate and sanitize user input before updating environment variables.
• Use a caching mechanism to reduce the number of requests to your API endpoint.

Environment Variable	Value
API_KEY	old-api-key
API_KEY	new-api-key

In conclusion, changing environment variable values at runtime in NEXT.JS without having to rebuild the project again is a powerful technique that can make your application more dynamic and flexible. By following the steps outlined in this article, you can implement this approach in your own NEXT.JS project and reap the benefits of dynamic configuration.

Here is the response:

Frequently Asked Question

In today’s fast-paced development world, we need to stay dynamic and adaptable. One crucial aspect of this is being able to modify environment variables in our Next.js project without having to rebuild the entire project from scratch. Sounds daunting? Don’t worry, we’ve got you covered!