Install VirtualBox and VNC server for CentOS 7

#!/bin/sh -e
CENTOS_REL=`sed -e 's/^.* release //' -e 's/ .*$//' /etc/centos-release`
KERN_VER=`uname -r`

if [ `id -u` != "0" ]; then
    echo "Please run as root user!"
    exit 1
fi

rpm -q kernel-devel-${KERN_VER} || wget http://ftp.riken.jp/Linux/cern/centos/${CENTOS_REL}/updates/x86_64/Packages/kernel-devel-${KERN_VER}.rpm
[ -f kernel-devel-${KERN_VER}.rpm ] && rpm -ivh kernel-devel-${KERN_VER}.rpm && rm -f kernel-devel-${KERN_VER}.rpm
rpm -q kernel-headers-${KERN_VER} || wget http://ftp.riken.jp/Linux/cern/centos/${CENTOS_REL}/updates/x86_64/Packages/kernel-headers-${KERN_VER}.rpm
[ -f kernel-headers-${KERN_VER}.rpm ] && rpm -ivh kernel-headers-${KERN_VER}.rpm && rm -f kernel-headers-${KERN_VER}.rpm

cat << 'EOF' > /etc/yum.repos.d/virtualbox.repo
[virtualbox]
name=Virtualbox Repository
baseurl=https://mirrors.tuna.tsinghua.edu.cn/virtualbox/rpm/el$releasever/
gpgcheck=0
enabled=1
EOF

yum makecache
yum -y install gcc make patch dkms qt libgomp
yum -y install fontforge binutils glibc-headers glibc-devel
export KERN_DIR=/usr/src/kernels/${KERN_VER}
yum -y install VirtualBox-5.1
systemctl start vboxdrv
rpm -q kernel-debug-devel && rpm -e kernel-debug-devel

yum -y install tightvnc-server
cp /usr/lib/systemd/system/vncserver@.service /etc/systemd/system/vncserver@:1.service
sed -i 's/<USER>/xuser/g' /etc/systemd/system/vncserver@:1.service
systemctl daemon-reload

mkdir -m 775 /home/xuser/.vnc
echo "xuserpass" | vncpasswd -f > /home/xuser/.vnc/passwd
chmod 600 /home/xuser/.vnc/passwd
chown -R xuser:xuser /home/xuser/.vnc

#systemctl enable vncserver@:1
#systemctl start vncserver@:1

firewall-cmd --permanent --add-service vnc-server
firewall-cmd --reload