[Yum] RFE for yum - pre- and postinstall hooks

[Michal Jaegermann]

How hard would be to add to yum hooks where one could specify,
mainly in a spec file although command line options would be handy
too if secondary, external programs to run before and after
transcations which add/replace/remove packages on a disk?

The main use I have in mind in this moment are installations where
at least some file systems are mounted read-only.  Then a program
(script) in a pre-hook could remount these rw and the one from a
post-hook could restore the original mount status.  Currently if
running in such situation yum with '-R <delay>' one has to use
not-that-sastisfactory hacks in order not to run into troubles.
Even when doing that "immediately" it is easy to forget that things
are not yet writable.

Quite likely with such hooks present some other uses will show
up too (like send mail somewhere about recent changes, for example).

   Michal