ubuntu18.04

sudo apt install nginx

/etc/nginx/nginx.conf

/etc/nginx/conf.d/proxy.conf

/etc/nginx/sites-enabled/default.conf を消す

sudo rm /etc/nginx/sites-enabled/default.conf

/etc/nginx/sites-available/xxxx.conf　を以下のように作成

server {
  server_name www.xxxx.com;
  location / {
      proxy_set_header X-Forwarded-Proto $scheme;
      proxy_set_header X-Forwarded-Host www.xxxx.com;
      proxy_pass http://localhost:8080;
  }
}

/etc/nginx/conf.d/proxy.conf　を以下のように作成

upstream proxybackend {
      server localhost:8080;
}
server {
      listen 0.0.0.0:80;
      server_name localhost;
      location / {
              proxy_pass http://proxybackend;
      }
}

nginx再起動

sudo systemctl stop nginx
sudo systemctl start nginx

/etc/apache2/ports.conf

 #listen 80
 listen 8080