31.7. 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.
Note
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.
Note
The post-install script is run in a chroot environment; therefore, performing tasks such as copying scripts or RPMs from the installation media do 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.
--log /path/to/logfile
- Logs the output of the post-install script. Note that the path of the log file must take into account whether or not you use the
--nochroot
option. For example, without--nochroot
:This command is available in Red Hat Enterprise Linux 5.5 and later.%post --log=/root/ks-post.log
with--nochroot
:%post --nochroot --log=/mnt/sysimage/root/ks-post.log
31.7.1. Examples
Register the system to a Subscription Asset Manager server, using the
--log
option to log the result (in Red Hat Enterprise Linux 5.5 and later):
%post --log=/root/ks-post.log /usr/sbin/subscription-manager register --username=admin@example.com --password=secret --serverurl=sam-server.example.com --org="Admin Group" --environment="Dev" --servicelevel=standard
Run a script named
runme
from an NFS share:
mkdir /mnt/temp mount -o nolock 10.10.0.2:/usr/new-machines /mnt/temp open -s -w -- /mnt/temp/runme umount /mnt/temp
Note
NFS file locking is not supported while in kickstart mode, therefore
-o nolock
is required when mounting an NFS mount.