Kickstart and roles

[David Lutterkort]

On Thu, 2006-04-13 at 21:38 -0700, Jane Dogalt wrote:
> This is a great idea and something I was planning on doing myself.  But for
> simplicity, it seems like this could be implemented dirt-simply (from an
> infrastructure impact point of view) via rpms.  I.e. rpms that are heavy on
> specifying dependencies and pre/post scripts, but probably very light on files
> (if not in fact lacking any rpm owned files).

While it's very tempting to do that, and I've seen quite a few places
that try to manage their config this way, pre/post scripts are a very
poor way to define the configuration of a machine: they leave no trace
of what they did, scripts by their very nature are entirely operational
(how would you display what the scripts do in a UI ?), they introduce
very tight coupling between dependent packages, and they give you no
help in figuring out if a machine's configuration deviates from what was
initially installed (think about finding out that somebody has
edited /etc/passwd and changed httpd's login shell to /bin/bash).

In addition, building rpm's to roll out config changes is a fairly
heavy-weight process - do you really want to rebuild an rpm just to fix
a typo in a config file somewhere ?

> Hopefully you write the rpm uninstall
> scripts with enough intelligence to revert the system exactly back to the
> preinstall state.

That's another problem with pre/post install scripts: all that
intelligence needs to be handcrafted for each script. And when things go
wrong, it's very hard to figure out what went wrong and why. Config mgmt
tools seem a much better solution for these kind of things than rpm's.

David