Fedora/RHEL6/CentOS6 install base: Registers FQDN with DHCP, sets local time zone, and updates system packages

install-base-centos6.sh

#!/usr/bin/env bash

echo "base: updating system packages"
yum -y update

echo "base: cleaning YUM metadata"
yum clean all
yum clean metadata

echo "base: registering hostname with DHCP server"
cat >> /etc/dhcp/dhclient.conf <<EOF
send fqdn.fqdn "$(hostname).local.tld";
send fqdn.encoded on
send fqdn.server-update off;
also request fqdn, dhcp6.fqdn;
EOF
/sbin/service network restart

echo "base: display hostname FQDN"
hostname -f

echo "base: setting local timezone"
if [ ! -L /etc/localtime ]; then
	sed -i '/ZONE/c \ZONE="America\/Los_Angeles"' /etc/sysconfig/clock
    rm -f /etc/localtime
    ln -s /usr/share/zoneinfo/America/Los_Angeles /etc/localtime
fi

echo "base: display date and time"
date

echo "base: disable ip6tables"
if [ `chkconfig --list | grep -c "^ip6tables "` -eq 1 ]; then
    echo "base: Deleting ip6tables service"
    service ip6tables stop
    chkconfig --del ip6tables
fi

echo "base: disable iptables"
if [ `chkconfig --list | grep -c "^iptables "` -eq 1 ]; then
    echo "base: Deleting iptables service"
    service iptables stop
    chkconfig --del iptables
fi