The following errors are generated from the RPMs %post phase when it is added during a Kickstart's %package phase:
Installing cfengine-community-3.5.3-1.x86_64
warning: cfengine-community-3.5.3-1.x86_64: Header V4 DSA/SHA1 Signature, key ID 89107b44: NOKEY
/var/tmp/rpm-tmp.aXAhoA: line 14: 1431 Segmentation fault (core dumped) /var/cfengine/bin/cf-key > /dev/null
/var/tmp/rpm-tmp.aXAhoA: line 20: /bin/cp: No such file or directory
/var/tmp/rpm-tmp.aXAhoA: line 37: ln: command not found
/var/tmp/rpm-tmp.aXAhoA: line 42: gzip: command not found
[this repeats a couple of times]
The RPM should depend on coreutils & gzip (e.g. Requires: gzip). This will eliminate the some of the errors.
The ' Segmentation fault (core dumped) /var/cfengine/bin/cf-key > /dev/null' error may be due to not having /dev mounted, but I have not yet checked.
The %pre & %post script also attempts to delete various files from /usr/local/sbin. These files don't exist, so the deletes should be made conditional.
All of this prevents CFEngine from being installed in the %package phase of a Redhat Kickstart script. The package could be installed in the %post phase, but one would have to disable the %post scripts and then manually run them when the server has booted. The work around would require manually downloading the RPM which would prevents Kickstart from automatically getting the latest release.