https://www.digitalocean.com/community/tutorials/como-instalar-o-nginx-no-ubuntu-18-04-pt
https://www.digitalocean.com/community/tutorials/how-to-optimize-nginx-configuration
https://www.digitalocean.com/community/tutorials/initial-server-setup-with-ubuntu-18-04
https://www.digitalocean.com/community/questions/keep-my-ssh-session-alive