9.7. Post-installation Script

You have the option of adding commands to run on the system once the installation is complete. This section must be at the end of the kickstart file and must start with the %post command. This section is useful for functions such as installing additional software and configuring an additional nameserver.

NoteNote
 

If you configured the network with static IP information, including a nameserver, you can access the network and resolve IP addresses in the %post section. If you configured the network for DHCP, the /etc/resolv.conf file has not been completed when the installation executes the %post section. You can access the network, but you can not resolve IP addresses. Thus, if you are using DHCP, you must specify IP addresses in the %post section.

NoteNote
 

The post-install script is run in a chroot environment; therefore, performing tasks such as copying scripts or RPMs from the installation media will not work.

--nochroot

Allows you to specify commands that you would like to run outside of the chroot environment.

The following example copies the file /etc/resolv.conf to the file system that was just installed.

%post --nochroot
cp /etc/resolv.conf /mnt/sysimage/etc/resolv.conf
--interpreter /usr/bin/python

Allows you to specify a different scripting language, such as Python. Replace /usr/bin/python with the scripting language of your choice.

9.7.1. Examples

Turn services on and off:

/sbin/chkconfig --level 345 telnet off
/sbin/chkconfig --level 345 finger off
/sbin/chkconfig --level 345 lpd off
/sbin/chkconfig --level 345 httpd on

Run a script named runme from an NFS share:

mkdir /mnt/temp
mount 10.10.0.2:/usr/new-machines /mnt/temp
open -s -w -- /mnt/temp/runme
umount /mnt/temp

Add a user to the system:

/usr/sbin/useradd bob
/usr/bin/chfn -f "Bob Smith" bob
/usr/sbin/usermod -p 'kjdf$04930FTH/ ' bob