The installer is puppet-based which could create surprises for users when they edit some configurations manually, and later run the installer again. Their manual changes could be overwritten. This should be made clear in the installer documentation.
If a user is worried that the installer might overwrite some changes, they can perform --noop and review the /var/log/katello-installer/katello-installer.log to see what changes would be applied.
In the case of overwriting changes the user did not expect they can be recovered. Files do get backed up, in the katello-installer logs anytime we overwrite a file, you'll see an entry like this about the Filebucket:
/Stage[main]/Dhcp/File[/etc/dhcp/dhcpd.conf]: Filebucketed /etc/dhcp/dhcpd.conf to puppet with sum 622d9820b8e764ab124367c68f5fa3a1
The old file is restorable with this command:
puppet filebucket -l restore /etc/dhcp/dhcpd.conf 622d9820b8e764ab124367c68f5fa3a1
Since this issue was entered in Red Hat Bugzilla, the release flag has been
set to ? to ensure that it is properly evaluated for this release.
Assigning to Charles for review.
Charles - perhaps at the start of Chapter 3 might be a good location for this?
Also, David's commit in Comment #3 contains some text that we can use for this. You can find it under the issue "BZ 1221217: Rerunning installer can overwrite manual changes" in the following -
The content is now live on the customer portal.