Saltar a contenido

Kickstart Files and Rocky Linux

Knowledge: ⭐ ⭐
Reading time: 15 minutes

Introduction

Kickstart files are an indispensable tool for installing and configuring Rocky Linux across one or more machines at once. You can use them to quickly set up everything from your favorite gaming workstation to deploying hundreds of machines in an enterprise organization. They save hours of time and effort manually configuring each machine in turn.

At the end of this article, you will have an understanding of how kickstart files work, how to create and apply your own kickstart file to a Rocky Linux ISO, and then be able to provision your own machine.

What are kickstart configurations?

Kickstart files are a set of configurations implemented by the user to quickly and easily deploy a Linux distribution. Kickstart files not only work on Rocky Linux, but also CentOS Stream, Fedora, and many other distributions.

How are kickstart configurations applied to an ISO?

Using mkkiso, a kickstart file is copied into the root directory of a Linux ISO. From there, mkkiso edits the /isolinux/isolinux.cfg and places the kickstart file there as a kernel cmdline parameter (inst.ks):

sudo mount -o ro,loop rocky-linux10-dvd-shadow.iso /mnt/
cat /mnt/EFI/BOOT/grub.cfg | grep shadow | head -1
linuxefi /images/pxeboot/vmlinuz inst.stage2=hd:LABEL=Rocky-10-1-x86_64-dvd quiet inst.ks=hd:LABEL=Rocky-10-1-x86_64-dvd:/rocky_linux10_shadow.ks

Once done, mkkiso produces a new ISO with the kickstart configuration built-in. When the ISO boots, anaconda runs the instructions listed in the kickstart file.

Prerequisites

  • Optional - deploy your kickstart ISO via a PXE Server: check out the guide on How to Setup a PXE Server on Rocky Linux 9.x to learn more.

  • One USB gen 3.0+ memory stick for a USB install.

  • A Rocky Linux 8, 9, or 10 Minimal ISO from https://rockylinux.org/download (the DVD ISO is not a requirement).

  • Follow the Custom Rocky Linux ISO Setup Steps guide to install the lorax package and how to generate a Rocky Linux kickstart ISO.

Kickstart examples

lang en_GB
keyboard --xlayouts='jp'
timezone Asia/Tokyo --utc
rootpw --iscrypted $6$0oXug1vTr7TO3kJu$/kvm.lctWsLDHaeak/YuUaEu26LzvNuE1L/tvUC4G91ZroChjDTUDwQDEkQfGhwQw4doiDcZc2P6et.zzRqOZ/ --allow-ssh
user --name howard --password $6$8wzUW5ipTdTs.MbM$1F6mPfqQAXPeSVArqT2r/GL6QljXs2dQWCcNGjQq5cpEPGWhNvOCAiVCDJRA0FZQpoTXJSBtNON2ZqvEMBUNX/ --iscrypted --groups=wheel
reboot
text
url --url='https://download.rockylinux.org/pub/rocky/10/BaseOS/x86_64/os/'
bootloader --location=boot --append="ro crashkernel=2G-64G:256M,64G-:512M rhgb quiet"
zerombr
clearpart --all --initlabel --disklabel=gpt
ignoredisk --only-use=nvme0n1
part /boot/efi --fstype=efi --size=600
part /boot --fstype=xfs --size=1024
part pv.0 --fstype=lvmpv --size=480000
volgroup rl --pesize=4096 pv.0
logvol / --vgname=rl --name=root --fstype=xfs --size=70000
logvol swap --vgname=rl --name=swap --fstype=swap --size=1024
logvol /home --vgname=rl --name=home --fstype=xfs --size=1000 --grow
network --device=enp4s0 --hostname=shadow --bootproto=static --ip=192.168.1.102 --netmask=255.255.255.0 --gateway=192.168.1.1 --nameserver=192.168.1.1 --activate
skipx
firstboot --disable
selinux --enforcing
firewall --enabled --ssh
%packages
@^server-product-environment
%end

%post
mkdir -p /mnt/storage1
mkdir -p /mnt/storage2
mkfs.xfs /dev/nvme0n1
mkfs.xfs /dev/sda
sync
udevadm settle
sleep 2
UUID_NVME0N1=$(blkid -s UUID -o value /dev/nvme0n1)
UUID_SDA=$(blkid -s UUID -o value /dev/sda)
if [ -n "$UUID_NVME0N1" ]; then
    echo "UUID=$UUID_NVME0N1 /mnt/storage1 xfs defaults,inode64 0 0" >> /etc/fstab
fi
if [ -n "$UUID_SDA" ]; then
    echo "UUID=$UUID_SDA /mnt/storage2 xfs defaults,inode64 0 0" >> /etc/fstab
fi
mount -U $UUID_NVME0N1 /mnt/storage1
mount -U $UUID_SDA /mnt/storage2
chown -R howard:howard /mnt/storage1
chown -R howard:howard /mnt/storage2
%end

lang en_GB
keyboard --xlayouts='jp'
timezone Asia/Tokyo --utc
rootpw --iscrypted $6$IjIs0nEufTOaj2cZ$EnZKdrjHQ9OmhePUMVWUcaJmmC0vU2L.b02lBMKmRMLq/VZOhnrgBO64ru29rFnB8HQsGo0cQLqBoLIpL7PbS1 --allow-ssh
user --name howard --groups wheel --password $6$OdZuQb9owvkol5gv$6X7w0VraE7hDSrrHS5oz9BvNACB.PcrNt5Ulka9/g1Sgxdzl93LAuGT3GH8a.4ZUpqzchKU3glgRyCWXhSN68. --iscrypted
reboot
text
url --url='https://download.rockylinux.org/pub/rocky/9/BaseOS/x86_64/os/'
bootloader --location=boot --append="crashkernel=1G-4G:192M,4G-64G:256M,64G:512M rhgb quiet"
zerombr
clearpart --all --initlabel --disklabel=gpt
ignoredisk --only-use=sda
part /boot/efi --fstype=efi --size=600
part /boot --fstype=xfs --size=1024
part pv.0 --fstype=lvmpv --size=120012
volgroup rl --pesize=4096 pv.0
logvol / --vgname=rl --name=root --fstype=xfs --size=70000
logvol swap --vgname=rl --name=swap --fstype=swap --size=1024
logvol /home --vgname=rl --name=home --fstype=xfs --size=1000 --grow
network --device=enp2s0 --hostname=mighty --bootproto=static --ip=192.168.1.104 --netmask=255.255.255.0 --gateway=192.168.1.1 --nameserver=192.168.1.1 --activate
skipx
firstboot --disable
selinux --enforcing
firewall --enabled --ssh
%packages
@^server-product-environment
%end

lang en_GB
keyboard jp106
timezone Asia/Tokyo --utc
rootpw <ROOT_PASSWORD_HERE> --iscrypted
user --name=howard --password=<USER_PASSWORD_HERE> --iscrypted --groups=wheel
reboot
text
url --url='https://download.rockylinux.org/pub/rocky/8/BaseOS/x86_64/os/'
bootloader --append="rhgb quiet crashkernel=auto"
zerombr
clearpart --all --initlabel
autopart
network --device=enp1s0 --hostname=rocky-linux8-slurm-controller-node --bootproto=static --ip=192.168.1.120 --netmask=255.255.255.0 --gateway=192.168.1.1 --nameserver=192.168.1.1
firstboot --disable
selinux --enforcing
firewall --enabled --ssh
%packages
@^server-product-environment
%end

Items of interest are highlighted below, with the focus being on the Rocky Linux 10 kickstart file. Any differences between kickstart files is also discussed:

Rocky Linux 10 kickstart file breakdown

rootpw

Warning

Always use the --iscrypted option for the root password, to ensure it is not displayed in plain text.

To generate a hash of the password you want, use the following openssl command and enter your password when prompted:

openssl passwd -6

For ssh access to the root account, add the --allow-ssh option to the rootpw line.

user

Similarly use the --iscrypted option to ensure your passwords are not shown in plain text.

If you want to make your user an administrator, add them to the wheel group with --groups=wheel

URL

Using the cdrom option with ignoredisk causes issues where Anaconda is not able to access the USB drive and hangs when checking the storage configuration. Using url --url works around that issue by downloading the installation from BaseOS.

Bootloader

Sets the bootloader's location and appends the required kernel cmdline parameters.

Zerombr

Ensures the destruction of any partition tables or other formatting options that Anaconda does not recognize on the chosen disk.

Clearpart

Erases all partitions on the target disk and sets the disk label as gpt.

Ignoredisk

If ignoredisk is not specified, anaconda will have access to all of the disks in the system. If specified, anaconda will only be able to use the disk as chosen by the user.

Part

part allows the user to specify the partitions they want to create. The above shows an example of a /boot, /boot/efi and Logical Volume Management configuration. This is what you get when you perform an automatic installation of Rocky Linux.

Volgroup

volgroup creates the LVM group. This example shows the selection of a name of rl and a Physical Extents (pesize) of 4096 KiB.

Logvol

Create logical volumes under the LVM group. To note the --grow option for the /home volume, to ensure the entirety of the LVM group's space is used.

Network

You can choose here to either statically or dynamically set your network configuration.

Skipx

Stops the configuration of the X server on the system.

Firstboot

In this case, we set the --disable flag, which stops the Setup Agent from starting when the system boots.

Firewall

Allowing ssh access through the firewall with --ssh is important, so you can login to your machine where console access is not available.

%packages

Lists the packages you want to install. In the example, the @^server-product-environment package group is the candidate for installation. This installs all the necessary packages for a stable Rocky Linux server.

Furthermore, you can also select individual packages to install here, exclude the installation of certain packages, and more.

%post

After the completion of the installation of the OS, you can list additional tasks to perform here too. In the example given, the author is configuring and mounting the additional storage that is present in their system.

The availability of other options are here too, such as %pre, %pre-install, %onerror, and %traceback. You can find more about these options with the references provided at the end of this document.

Differences of note between Rocky Linux kickstarts

Rocky Linux 10 and 9 define the keyboard layout (example with a Japanese keyboard) in the following style:

keyboard --xlayouts='jp'

However, Rocky Linux 8 defines the keyboard layout as:

keyboard jp106

For ssh access to the root account, Rocky Linux 8's kickstart file does not need the --allow-ssh flag added.

The crashkernel kernel cmdline parameter differs between all three Rocky Linux versions, please keep that in mind when setting the parameter.

In the Rocky Linux 8 kickstart example (this applies to all Rocky Linux versions), if you wish to automatically partition your drive, just set the autopart option.

Conclusion

If you want to automate your Rocky Linux installations, then kickstart files are the way to go. This guide is just the tip of the iceberg of what you can accomplish with kickstart files. For a great resource on every kickstart option available with examples, check out Chris Lumens and the Anaconda installer team's kickstart documentation2.

For those wishing to take automation further in the realm of virtual machine deployment and also utilize their kickstart knowledge, Antoine Le Morvan wrote an excellent guide1 on just how to do that with packer.

The Rocky Linux Release Engineering Team also have multiple kickstart file examples available at the Rocky Linux repository4.

Finally, if you have access to a Red Hat account, there is a Kickstart Generator that Red Hat provides, which allows you to quickly and easily create kickstart files via a UI.

References

  1. "Automatic template creation with Packer and deployment with Ansible in a VMware vSphere environment" by Antoine Le Morvan https://docs.rockylinux.org/10/guides/automation/templates-automation-packer-vsphere/
  2. "Extensive kickstart documentation" by Chris Lumens and the Anaconda installer team https://pykickstart.readthedocs.io/en/latest/kickstart-docs.html
  3. "Red Hat Kickstart Generator (requires a Red Hat Account)" by Red Hat https://access.redhat.com/labsinfo/kickstartconfig
  4. "Rocky Linux Kickstart Repository" by the Rocky Linux Release Engineering Team https://github.com/rocky-linux/kickstarts/tree/main Footer

Author: Howard Van Der Wal

Contributors: Steven Spencer