Labuntu

I’m going to upgrade my computer labs running Ubuntu to 12.04. This isn’t as simple as it sounds as I use a set of technology which is either not supported any more or stuff I wrote to make things work. For example:

  • Netbook launcher – no longer supported and doesn’t work any more – solution, program a new one.
  • Login Screen – I use the gnome2 gdm as the backend for my logon screen. Ubuntu not uses the rather inflexible lightgm. solution – replace lightgm with GDM for gnome3 and update code.
  • User Management – I currently use nfs/rsync method which is why I’ve been banned by the Geneva convention. The ideal option would be to use LDAP, but it’s so excruciatingly hard to setup that my 19 attempts have all failed. Solution – create a set of juju charms and interfaces for openldap, kerberos, the user management setups that EVERYONE uses.
  • Printers – I need to continue to use cups, but need quota management. solution – Add PyKota to manage quotas, package it up as it’s unpackaged and make it a charm with ldap interface.
  • Lab Sessions – Update lab session manager to use LDAP, improve it’s reconfigurability and add the printer and nfs quota to the information shown

This is by no means the end of the list, but already I have my work cut out to make sure that this stuff works and that it’s available for other people to use. And all this needs to happen before I can touch one computer with the 12.04 CD. If anyone would like to help, I’d be grateful. After all this, I see no reason to beat about the bush and I might as well release labuntu or some such for internet cafes, libraries, and other public access computer systems.

Ideas?

10 Responses to “Labuntu”

  1. I’ll be interested to know what else you run into. We’re on 10.04 in the school labs we’re deploying and we’ll be looking at an upgrade this summer (hopefully!).

  2. jef spaleta says:

    i thought the whole point of lightdm was to be more extensible.

    -jef

  3. doctormo says:

    jef – No, it’s to be quicker. since gdm can run any program and is practically a desktop. It doesn’t get more flexible. But that’s why gdm is slower.

  4. Brett says:

    I appreciated the work you did to keep the Netbook launcher alive. I really loved that interface for my netbook.

    I don’t think I have the skills to help much, but if you’re thinking of programming a new one, I can do some testing and feedback at the very least.

  5. doctormo – no, LightDM was designed primarily to be more flexible… Note that in Ubuntu the visual component of LightDM is Unity Greeter (a separate project) which is designed only to meet the requirements of Unity. There are other greeters available which are more flexible, but what works best depends on the modification you need.

  6. doctormo says:

    @Robert – Was is the private DBus interface of GDM that was inflexible? Once I got past that, everything was really great.

    On the other hand, don’t you have to write LightDM greeters in C?

  7. doctormo, the private interface was the main problem, it was undocumented, made no interface guarantees and we needed to pass through additional information and that was very difficult with the layers inside GDM. For Ubuntu we really needed a Unity style greeter in a fully functional display manager and GDM was focussed on only supporting the GNOME interface (which is fine). The Unity greeter would be easier to maintain if it could be developed independently of the display manager and continue to work between upgrades. Other projects like Elementary, LXDE etc have similar requirements so I saw an opportunity there to work on a new DM.

    LightDM provides two libraries for greeters – liblightdm-qt and liblightdm-gobject. The GObject bindings have introspection and Vala support so you can write greeters in C, C++, Vala, Python, Javascript (and I have heard of/seen greeters written in all those languages).

  8. doctormo says:

    Robert – That’s quite a lot of very useful information. Thanks! I will need to look into it perhaps for version 2. Do you think lightdm will be happy to use ldap, checking for usernames and real names etc? Does it support face pictures? I’m guessing yes.

  9. doctormo, depends on how you’ve used LDAP of course! I’m guessing that your greeter process contacts the LDAP server to do the searching, then provides the chosen username to the daemon which when uses a PAM LDAP module to do the authentication. It supports user information like faces which is sourced from Accounts Service.

  10. Jeremy Bicha says:

    Also, GDM is a huge pain to maintain for Debian and Ubuntu. If you’re curious, look at http://anonscm.debian.org/viewvc/pkg-gnome/desktop/unstable/gdm3/debian/patches/

    Notice that we’re still on GDM 3.0, not 3.4. GDM is becoming less and less interesting if you want to do things besides GNOME Shell.

    Every Ubuntu 12.04 flavor except Kubuntu is using LightDM, and Kubuntu is considering switching for 12.10.