502 bad gateway Nginx
If you are getting the
502 bad gateway error when accessing a Nginx server,
here are a few solutions:
Check if Nginx is running
To check if Nginx is running run the following command:
systemctl status nginx
You will see the following output if the Nginx is running:
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/
Or this output if the server is not running:
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/
To start the Nginx in case it is not running, run the following command:
systemctl start nginx
Then check the status again 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 the config syntax
To check the config syntax, run the following command:
If there is a problem with the config syntax, it will be listed in the output of this command. You will need to fix each problem and then restart Nginx using the following command:
systemctl restart nginx
Check the error logs
If Nginx is running and config syntax is OK, run the following command to display error logs:
tail -f /var/log/nginx/error.log
Check for the permissions
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'
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