How to integrate kickstart file in the PXE Server to automate Operating System Installation

In my previous post, I have described how to start with the PXE server for the network operating system installation. See the below link, if missed out.

"How to configure PXE (Network Boot) installation Server on Red Hat Enterprise Linux 7"

Now I am going to create a kickstart file and integrate it with the PXE Boot server to automate Operating System Installation, without any user intervention. During the Operating System Installation kickstart file will decide:

• The filesystem structure.

• The package group that will be installed

• Any post configuration and so on.

Step:1 Need to set the root password (encrypted string) in the kickstart file. OpenSSL command can help us to convert any text to encrypted string as below:

# openssl passwd -1 Redhat123
$1$jiA3FLdA$YHu//9xCxolp2lhMzbqYO1

Step:2 To create a sample Kickstart file that can be used to install RHEL.

# vi /var/ftp/pub/rhel7-ks.cfg
######
#platform=x86, AMD64, or Intel EM64T
#version=DEVEL
# Firewall configuration
firewall --disabled
# Install OS instead of upgrade
install
# Use FTP installation media
url --url="ftp://192.168.122.144/pub/rhel7/"
# Root password
rootpw --iscrypted $1$jiA3FLdA$YHu//9xCxolp2lhMzbqYO1
# System authorization information
auth useshadow passalgo=sha512
# Use graphical install
graphical
firstboot disable
# System keyboard
keyboard us
# System language
lang en_US
# SELinux configuration
selinux disabled
# Installation logging level
logging level=info
# System timezone
timezone Asia/Kuala_Lumpur
# System bootloader configuration
bootloader location=mbr
clearpart --all --initlabel
part swap --asprimary --fstype="swap" --size=1024
part /boot --fstype xfs --size=300
part pv.01 --size=1 --grow
volgroup root_rhel pv.01
logvol / --fstype xfs --name=lv_01 --vgname=root_rhel --size=1 --grow
%packages
@^minimal
@core
kexec-tools
%end
%addon com_redhat_kdump --disable --reserve-mb='auto'
%end
%post --erroronfail
nodectl init
%end

Note: The below labs URL is provided by Red Hat and can be used to build your customized Kickstart file: https://access.redhat.com/labs/kickstartconfig/

Step:3 To add/change PXE menu file (/var/lib/tftpboot/pxelinux.cfg/default) and make sure the following contents into the pxe menu file.

# vim /var/lib/tftpboot/pxelinux.cfg/default
::::::::::::: CUT SOME OUTPUT :::::::::::::  
label 5
menu label ^5) Install RHEL 7 1xETH,KS
kernel rhcos/vmlinuz
append initrd=rhcos/initrd.img inst.repo=ftp://192.168.122.144/pub/rhel7/ ks=ftp://192.168.122.144/pub/rhel7-ks.cfg
::::::::::::: CUT SOME OUTPUT :::::::::::::  

Step:4 To verify and boot the client systems with the PXE boot with the KS option.

We can select the installation method 5 from the PXE Boot menu screen. And after that, It will complete the installation without prompting any further input from you.

Hope this document will help.