Preparing CentOS template for VMware vSphere

Preparing CentOS template for VMware vSphere.md

Preparing CentOS template for VMware vSphere

• Preparing CentOS template for VMware vSphere
  • Stopping logging services
  • Disabling consistent network device naming
  • Updating system
  • Installing addtional tools
  • Removing old kernels
  • (Optional) Migrating friewalld to iptables
  • Disabling network manager
  • Removing logs
  • Deleting sshd keys
  • Additional cleaning
  • Deleting bash history
  • Generalizing

Stopping logging services

service rsyslog stop 
service auditd stop

Disabling consistent network device naming

ln -s /dev/null /etc/udev/rules.d/80-net-name-slot.rules
sed -i 's/rhgb quiet/net.ifnames=0 biosdevname=0 ipv6.disable=1/' /etc/default/grub
grub2-mkconfig -o /boot/grub2/grub.cfg
grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg
echo 'TYPE="Ethernet"
BOOTPROTO="dhcp"
DEFROUTE="yes"
NAME="eth0"
DEVICE="eth0"
ONBOOT="yes"' > /etc/sysconfig/network-scripts/ifcfg-eth0

Updating system

yum update -y

Installing addtional tools

yum install -y open-vm-tools bash-completion yum-utils

Removing old kernels

package-cleanup -y --oldkernels --count=1

(Optional) Migrating friewalld to iptables

yum -y install iptables-services
systemctl enable iptables.service
systemctl stop firewalld 
systemctl start iptables
systemctl disable firewalld
systemctl mask firewalld

Configuring iptables to allow all connection

iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
iptables -P INPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -P OUTPUT ACCEPT
service iptables save

Disabling network manager

systemctl disable NetworkManager.service
systemctl stop NetworkManager.service
systemctl mask NetworkManager

Removing logs

logrotate -f /etc/logrotate.conf 
rm -f /var/log/*-???????? /var/log/*.gz 
rm -f /var/log/dmesg.old 
rm -rf /var/log/anaconda 
rm -rf /var/cache/yum
cat /dev/null > /var/log/audit/audit.log 
cat /dev/null > /var/log/wtmp 
cat /dev/null > /var/log/lastlog 
cat /dev/null > /var/log/grubby

Deleting sshd keys

rm -f /etc/ssh/ssh_host_*

Additional cleaning

yum clean all
rm -rf /root/.ssh/
rm -f /root/anaconda-ks.cfg
rm -rf /tmp/*

Deleting bash history

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

Generalizing

sys-unconfig