Many thanks to the Linux Community.

Sources:

Ubuntu Server Documentation
Nginx PPA
NGINX Gists
Konstantin Kovshenin
Github fail2ban
Github ModSecurity
Github ModSecurity-nginx
Nginx logging

Images:

Photo by Ilya Pavlov on Unsplash
Photo by Nejc Soklič on Unsplash
Photo by Denny Müller on Unsplash
Photo by Gabriel Heinzer on Unsplash
Photo by Emiliano Bar on Unsplash