I have /tmp on a separate partition, and mounted with noexec. I am using Debian.
The installation of some packages fails, because the post-installation scripts of some packages need to run from /tmp.
I was wondering if it would be possible to "hook" a simple script to apt-get, which would be run every time before apt-get, and remount /tmp to exec. And similarly, remount it to noexec after apt-get has finished.
You can use dpkg's hook system to remount it -- put this in /etc/apt/apt.conf.d/00exectmp:
DPkg::Pre-Invoke {"mount -o remount,exec /tmp";};
DPkg::Post-Invoke {"mount -o remount /tmp";};
Mumble, you can simply replace apt-get with a script of yours.
Move apt-get to real-apt-get and, then, create a script called apt-get like this one:
#!/bin/sh
mount -o remount -o ... /tmp
real-apt-get "$@"
mount -o remount -o ... -o noexec /tmp
In any case, I do not like this solution. It is easier change the temporary directory environment variable when you need it. Something like (sh style):
mkdir /root/mytmp
TMPDIR=/root/mytmp
export TMPDIR
apt-get ...
rm -rf /root/mytmp
This way apt-get will use /root/mytmp as temporary dir. No need to change the system.
apt package is upgraded, that is. I don't recommend messing with files supplied by packages.