Identify virtual machine technology
virt-what is a shell script which can be used to detect if the program is running in a virtual machine.
It will identify what VM technology is used for current VM. For example KVM, Xen, HyperV etc.
On CentOS 7, install virt-what with
yum -y install virt-what
On Debian/Ubuntu
apt install virt-what
Example
See VPS