Help Needed: Nginx Reverse Proxy to Docker App on App Platform Results in 502 Error

Hello,

In addition to what has already been mentioned, I would recommend following these steps in case that you are having any problems with your nginx server and you are unsure on what the problem is:

• Check your nginx config syntax:

nginx -t

If you get an error, you would need to fix that problem and then you could restart nginx:

systemctl restart nginx

• If you get Syntax OK when running nginx -t then your confiruation is correct, so I would recommend checking your error logs:

tail -f /var/log/nginx/error.log

The log should contain the actual error rather than the generic 502 error. Feel free to share the output of the log here!

• Next, check if your Docker container is running and that it is binding to the correct port with:

docker ps -a

Feel free to share the output here and also your Nginx server block reverse proxy config.

And here is also a quick video demo on how to do that as well:

Hope that this helps!

- Bobby

To resolve the 502 error, ensure your Docker container’s app is accessible from the Droplet. Check firewall settings, ensure Nginx is correctly configured with the upstream server details, and verify that the App Platform’s app allows external connections. Also, confirm that Nginx’s proxy settings match the app’s requirements.

Heya,

You can create a reverse proxy from Nginx to the URL generated from the App platform.

A similar idea was shared before in the community before:

https://www.digitalocean.com/community/questions/reverse-proxy-from-droplet-to-app-platform

One other option here would be to just setup a redirect for domain.com/app) to go to a app.domain.com subdomain. That way you will not have to setup a proxy service to handle all requests, but you can just point the blog subdomain A record to the Droplet and then keep the main domain pointed to the App Platform.

Regards