nginx is an open source reverse proxy that can be used to solve a number of issues.
Typically one would use this when presenting one public ip and you want to either filter or redirect this traffic to another processor; weather that be on the same machine or yet a different machine. The reverse proxy can even be used to redirect ports so that what comes in as port 80 can be redirected to a different port.
This could also be convenient if for example you were using multiple x each with their own ip.
To get the signing key for the APT repository.
To add the key to for the package.
apt-key add nginx_signing.key
As a quick edit to add a new source for the repository.
Note in this instance the config reads hirsute to designate the version of Ubuntu being used. You would need to alter the list add according
deb [arch=amd64] http://nginx.org/packages/mainline/ubuntu hirsute nginx
Now you can simply to update the local apt repository indexes and then finally to install nginx
sudo apt update
sudo apt install nginx
The following code can be used to check the syntax of the nginx config files.
The following command can be used to reload nginx configuration.
nginx -s reload