ubuntu server 16.04.02 install ubuntu-desktop

Add cdrom as a package source (ubuntu-desktop is not included, just add a note)
(Insert the cdrom into system)
# sudo -i
# mount /dev/cdrom /media/cdrom
# apt-cdrom -m -d=/media/cdrom add

Set the LAN setting
# ifconfig -a
Remember the interface name you want to config (enp24s0 for example)
Edit the file /etc/network/interfaces
Add following two line
auto enp24s0
iface enp24s0 inet dhcp

restart the networking service
# systemctl restart networking.service

Add Proxy setting to apt
Add a line in /etc/apt/apt.conf (if the file not exist, create a new one)
Acquire::http::Proxy "http://username:password@proxy.hinet.net:80";

# apt-get update
# apt install --no-install-recommends ubuntu-desktop
# apt-get install gnome-terminal

Allow root login through remote ssh
Edit the file /etc/ssh/sshd_config
PermitRootLogin prohibit-password
to
PermitRootLogin yes

Then restart the sshd service
# systemctl restart sshd.service

Enable sshd
# sysv-rc-conf sshd on