Create Custom CentOS 6x or 7x KVM template for Proxmox VE

Create a KVM with custom HDD, RAM, CPU, etc. using CentOS 6 or 7 minimal
Disable selinux
Edit the /etc/selinux/config

vi /etc/selinux/config

Change SELINUX=enforcing to SELINUX=disabled

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
# enforcing - SELinux security policy is enforced.
# permissive - SELinux prints warnings instead of enforcing.
# disabled - No SELinux policy is loaded.
SELINUX=enforcing
# SELINUXTYPE= can take one of these two values:
# targeted - Targeted processes are protected,
# mls - Multi Level Security protection.
SELINUXTYPE=targeted

Turn off Firewall
(CentOS 7x)

systemctl stop firewalld
systemctl disable firewalld
yum -y install net-tools

Turn off Firewall
(CentOS 6x)

service iptables save 
service iptables stop 
chkconfig iptables off

Create a bash shell script seal.sh

vi /usr/src/seal.sh

Paste following script in the seal.sh file

#!/bin/bash 
echo "Seal This Centos 6x and 7x Server"
yum clean all
> /etc/machie-id
rm -f /etc/ssh/ssh_host_rm -rf /root/.ssh/
rm -f /root/anaconda-ks.cfg
rm -f /root/.bash_history
unset HISTFILE
rm -f /var/log/boot.log
rm -f /var/log/cron
rm -f /var/log/dmesg
rm -f /var/log/grubby
rm -f /var/log/lastlog
rm -f /var/log/maillog
rm -f /var/log/messages
rm -f /var/log/secure
rm -f /var/log/spooler
rm -f /var/log/tallylog
rm -f /var/log/wpa_supplicant.log
rm -f /var/log/wtmp
rm -f /var/log/yum.log
rm -f /var/log/audit/audit.log
rm -f /var/log/tuned/tuned.logroot

Go to use /usr/src folder and make script executable

cd /usr/src
chmod +x seal.sh

Run seal.sh script

./seal.sh

Clear History

cat /dev/null > ~/.bash_history && history -c && exit

Generalize (seal) a Linux virtual machine using the sys-unconfig command before making it into a template. This prevents conflicts between virtual machines deployed from the template

sys-unconfig

 

Using Proxmox web interface Stop VM

Next right click on the VM and Convert to Template

Your Custom CentOS Template is ready.