Connect domain name with Linux VPS server ip using nginx

Question

I have a VPS Linux (Ubuntu) server and I would like to connect a domain name with my server IP through nginx, but nginx does not work. I have checked the following:

$ sudo systemctl reload nginx

nginx.service is not active, cannot reload

$ sudo service nginx start
Job for nginx.service failed because the control process exited with error code.
See "systemctl status nginx.service" and "journalctl -xe" for details.

$ systemctl status nginx.service
● nginx.service - A high performance web server and a reverse proxy server
     Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
     Active: failed (Result: exit-code) since Sun 2022-05-15 18:53:40 CEST; 11s ago

$ sudo nginx -t
nginx: [emerg] unknown "connection_upgrade" variable
nginx: configuration file /etc/nginx/nginx.conf test failed

In relation to run an app on my own domain, I have a nginx configuration file:

$ sudo cat /etc/nginx/sites-available/shiny

server {

        server_name my_domain.com;

        location / {
                proxy_pass http://localhost:80;
                proxy_redirect / $scheme://$http_host/;
                proxy_http_version 1.1;
                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection $connection_upgrade;
                proxy_read_timeout 20d;
                proxy_buffering off;
        }

}

I would appreciate if someone could help me with this issue.

Answer 1

just replace proxy_set_header Upgrade $http_upgrade; in /etc/nginx/sites-available/shiny with this :

proxy_set_header Connection "upgrade";

and then run nginx -t to test the configuration file, the output should be like this if everything was alright :

nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

then run nginx -s reload so the nginx will update the configurations on the fly.

and don't forget to delete that proxy_redirect / $scheme://$http_host/; and add a listen 4444 at the end of server block to specify the listen port.