node_exporter is a utility that export node information via prometheus
API. It takes care of host related metrics such as CPU and memory.
The install script, download the node_exporter binaries, create a link
in /usr/bin.
On OS with systemd supported it would enable and start the installed
service file to start as a service. On others (ubuntu) it would create a conf file and start it.
The installation should be done using sudo.
After a successful installation, the node_exporter would run as a
service.
Signed-off-by: Amnon Heiman <amnon@scylladb.com>