Скачать или смотреть Resolving Nginx Reverse Proxy Subdomain Issues: Quick Fix for Your NodeJS Apps

Struggling with your Nginx reverse proxy setup for subdomains? Learn how to quickly troubleshoot and resolve common issues, focusing on NodeJS applications.
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This video is based on the question https://stackoverflow.com/q/76917443/ asked by the user 'Aayush' ( https://stackoverflow.com/u/159475/ ) and on the answer https://stackoverflow.com/a/78032581/ provided by the user 'Aayush' ( https://stackoverflow.com/u/159475/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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The Common Woe: Nginx Reverse Proxy Subdomain Not Working

Setting up a reverse proxy with Nginx can be tricky, especially when it involves running multiple applications under different subdomains. You might find yourself in a situation where your NodeJS apps, running on your local server, don't seem to work as expected through your reverse proxy. This situation raises questions and confusion, especially for those who are new to server configurations.

In this guide, we will delve into the common problems faced when using Nginx as a reverse proxy and how to easily resolve them.

The Setup

Consider the following situation: You have two NodeJS applications running on your server, one on http://localhost:3000 and the other on http://localhost:3001. You are trying to access these via the following subdomains:

http://test.com for the application on port 3000

http://api.test.com for the application on port 3001

Nginx Configuration Files

You might have something that resembles the following in your Nginx configuration files.

api.test.com Configuration

[[See Video to Reveal this Text or Code Snippet]]

test.com Configuration

[[See Video to Reveal this Text or Code Snippet]]

This setup seems correct on the surface. Nonetheless, if both applications are not working, it can leave you scratching your head.

The Solution: Troubleshooting Your Nginx Reverse Proxy

In our example, the issue was resolved quickly with a simple change. Here’s where many users might overlook an important aspect: Firewall Configuration.

Understanding the Firewall

Most cloud service providers like DigitalOcean or AWS Lightsail typically have built-in firewalls (such as UFW - Uncomplicated Firewall) that can block incoming traffic to your application. Here’s the process to resolve such issues:

Access Your Control Panel: Log into the dashboard provided by your cloud service.

Configure Firewall Rules: Ensure that you allow HTTP traffic on port 80. This step is critical as it permits incoming requests to reach your Nginx server.

Double-check Other Settings: If you're using HTTPS, also verify that port 443 is allowed.

In our specific case, the issue was that HTTP traffic was not permitted, leading to the failure of accessing the applications through http://test.com and http://api.test.com.

Verify Your Configuration

After making the changes, remember to:

Restart Nginx: You can do this by running sudo systemctl restart nginx in the terminal.

Test Your Setup: Once Nginx has restarted, try accessing your applications again.

Key Takeaway

Configuring an Nginx reverse proxy requires careful attention to detail, especially regarding firewall settings. Remember to always ensure that necessary ports are open for traffic.

By following these simple steps and confirming your firewall settings, you can swiftly resolve issues with your Nginx reverse proxy setup. Happy hosting!