Nginx:

/etc/nginx/sites-available/

server {
	listen 8080 default_server;
	listen [::]:8080 default_server;
	root /var/www/html;
	location / {
		# First attempt to serve request as file, then
		# as directory, then fall back to displaying a 404.
		try_files $uri $uri/ =404;
	}

/etc/nginx/conf.d/

server
{
        listen 8080;
        listen [::]:8080;
        return 301 https://$http_host$request_uri;

        access_log  /dev/null;
        error_log  /dev/null;
}

Caddy

:80 {
     respond "80"
}