Re: How to consistently install a set of packages?

[David <bouncingcats@gmail.com>]

On 06/06/2013, James Richardson <james@jamestechnotes.com> wrote:
> David wrote:

[...]

>> Because some packages create users and groups, I want to be sure that
>> these packages are installed in the same sequence on every PC so that
>> numeric uid & gid in /etc/passwd and /etc/group end up the same on all
>> PCs. This will make admin easier when keeping the shared data in sync
>> if the numeric uid and gid are the same in every OS.

> The only thing I can suggest (and I am by no means an expert), is to
> create the users/groups before installing the packages. You can use dpkg
> --get/--set-selections to set the selection state of the packages, but
> as this doesn't actually install anything, I would doubt it would give
> apt-get/aptitude any hints about ordering, but if the user/groups
> existed before hand it should still be ok.

Hi James

Thank you for your thoughts. I appreciate your lateral thinking which
is appealing. But I wonder how a package install process would make
the decision to take over a pre-existing user or group?

For example, if I created user=approx and then installed the approx
package which wants to run as user=approx, how thoroughly would its
installer script assess if the pre-existing user=approx is free for
its use? If there already was some other unrelated user=approx, it
would be undesirable for the approx package to assimilate that user.

And would each package that wants to do similar behave consistently?

Any thoughts on that?

My guess would be that a package install would probably abort if the
user or group it wanted was already in use. Or perhaps the installer
will ask what to do? I'd prefer if it would run unattended. I can't
set up a test immediately, but if necessary I can test this later in
the week.