Serve go / Golang HTTP/HTTPS app with Nginx as a subdomain

go-http-nginx.conf

upstream go-http-backend {
    server 127.0.0.1:3000;
    keepalive 20;
}

server {
    listen 80;
    server_name sub.domain.com;
    
    # adjust as per app's requirement
    access_log off;
    error_log /dev/null crit;

    # required for keepalives to be used
    proxy_http_version 1.1;
    proxy_set_header Connection "";
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $remote_addr;
    proxy_set_header Host $host;

    location / {
        proxy_pass http://go-http-backend;
    }
}