Multiple package installs with subordinates?

[Jorge O. Castro]

Liam Young has a merge proposal for gunicorn this morning that checks
for an apt lock before continuing :
https://code.launchpad.net/~gnuoy/charms/precise/gunicorn/gunicorn-apt-lock-checking

And looking at it reminded me that we should start to discuss multiple
installations on the same instance, possible at the same time.

There's a tool called aptdcon[1] which can do "aptdcon -i packagename"
and will then hand off the install to aptdaemon, which is nice because
if that takes a while and then a subordinate gets installed and also
uses aptdcon it will just add the new packages to it's installation
queue and continue.

But before we do things like recommend aptdcon and/or go through all
the charms fixing them up I'd like to get consensus on how to solve
this problem. Also I've heard people talking about using things like
LXC so that the subordinate and "master" never need to clash, but I
don't know if that's a planned feature for subordinates or what.

[1]: http://manpages.ubuntu.com/manpages/precise/man1/aptdcon.1.html

--
Jorge Castro
Canonical Ltd.
http://juju.ubuntu.com