Question

502 bad gateway nginx

Hello friends want a help from you! Because then I’m having a problem Error 502 Bad gateway always nginx. Everything was normal, but until now I still don’t see a tutorial in 2016, which corresponds to it, but I think it’s bug. Can someone help me

Show comments

Submit an answer

This textbox defaults to using Markdown to format your answer.

You can type !ref in this text area to quickly search our full set of tutorials, documentation & marketplace offerings and insert the link!

Sign In or Sign Up to Answer

These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.

Accepted Answer

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 if nginx is running:
systemctl status nginx

If nginx is running you should see something like this:

● nginx.service - The nginx HTTP Server
   Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2019-11-19 09:37:46 UTC; 2 days ago
     Docs: https://httpd.nginx.org/docs/2.4/

If nginx is not running then the output would look like this:

● nginx.service - The nginx HTTP Server
   Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
   Active: inactive (dead) since Fri 2019-11-22 08:41:01 UTC; 39s ago
     Docs: https://httpd.nginx.org/docs/2.4/
  • If nginx is not running you could start it with:
systemctl start nginx

Then check the status agian and make sure that nginx remains running.

  • If nginx did not start after a reboot, you could enable it so that it starts after the next reboot:
systemctl enable nginx
  • 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
  • Check the permissions of the files and folders in your document root:

Find the user that your nginx service is running as:

ps auxf | grep nginx

If you are using Ubuntu, the user should be www-data, so you would need to make sure that your files and folders are owned by that user, so nginx could read and write to those files:

chown -R www-data:www-data /var/www/yourdomain.com
  • Check if nginx is binding to the default ports:
netstat -plant | grep '80\|443'
  • Check if ufw allows TCP connections on port 80 and 443:
ufw status

If this is the case, you can follow the steps from this article here on how to configure your ufw:

https://www.digitalocean.com/community/tutorials/how-to-set-up-a-firewall-with-ufw-on-ubuntu-18-04

That is pretty much it, with all of the above information you should be able to narrow down the problem.

For more information I would suggest checking out this article here:

https://www.digitalocean.com/community/tutorials/how-to-troubleshoot-common-site-issues-on-a-linux-server

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

Hope that this helps! Regards, Bobby Source: How to Troubleshoot Common Nginx Issues on Linux Server?

 sudo chown user:group -R /run/php

… that fixed my issue for me … Ubuntu 18.04

Try run this command systemctl start php-fpm systemctl enable php-fpm

Lots of possibilities but if you opted to use FPM most probably you are pointing to the wrong version.

fastcgi_pass unix:/var/run/php/php<YourPHPVersionHere>-fpm.sock;