DoctorMo's Blog

For today’s video blog I’m tackling the ideas behind Ubuntu the platform and Ubuntu the product, courtesy of Ayatana Mailing List. Nobody doesn’t like good Ayatana! Basically I dig into the problems between a One and Only vision and the more flexible, but harder to do, platform model of design.

With visual aids thanks to Inkscape!

Video Problems: Go directly to the video on blip.tv here and download the source ogv here.

What are your thoughts?

Update from my previous post: Here we have a branch containing a working gdm greeter user interface with a nice python module set for interacting with the gdm greeter service.

What’s nice about this code is how little of it you need to hack on the gdm. Binding up the username and password box to the events pretty much does everything. Most of the original functionality is simple to do.

The design isn’t final, there are gtk limitations and since gdm doesn’t really do clutter or opengl, it’d be impossible to do anything more interesting unfortunately.

The difference in functionality here is that you enter your full name (not your username) and it suggests people to you. The idea with this is that if you type in your name and you’re not a user, the next screen you see will be a register screen.

I selected my name from the list and then entered my passphrase:

Then it will log you in exactly as it should. Have a look at the code and see if you can hack on the gdm, it’s really very easy if you know a bit of python and gtk.

Comment if you do anything interesting.

PJ of Groklaw is shuttering groklaw, so there’ll be no more new content on the website. Groklaw has been a fantastic reference, both in following the SCO saga and with learning more about copyright and other legal issues. The newspicks were some of the best selected of any linux related website I know and they will be missed.

For you PJ, a cartoon that took me all day to draw:

Thanks for all the fish. Can’t wait to see what your next case is!

In Ubuntu we use Gnome and the GDM (Gnome Display Manager) login screen called gdm-simple-greeter. This program is fairly fully featured for a normal Ubuntu install and even has a configuration in /etc/gdm/custom.conf which you can play around with.

But, I want to do something special, I’m making a computer lab with a registration screen and other fun stuff. I’ll blog about the designs and code for that in a future blog post. Today I’m going to talk about how I made a gdm greeter in python despite the lack of documentation and the round-about API challenges.

First thing to realise is that GDM 2.30 which shipped with Ubuntu 10.10 has a rich and full service/client API via DBus. This allows me to do what I’m going to do because it allows my program to act just like the shipped simple greeter. Only a single greeter can talk over the DBus API and it’s worth noting that the API isn’t over the normal System or Session Dbus, it’s over a private dbus unix socket to prevent all sorts of security issues with passing passwords around.

I first deactivated the GDM greeter: `mv /usr/share/gdm/autostart/LoginWindow/gdm-simple-greeter.desktop ~/Desktop/` this will now not allow you to log into Ubuntu!

Next I developed a script which uses python’s DBus lower layers to connect over the private dbus address. The address is given to us via an environment variable ‘GDM_GREETER_DBUS_ADDRESS’ and we just feed that in as it’s randomly generated. Fill in the PASSWORD and USERNAME variables to have GDM handle the communication and log in, this is certainly not a script you should leave installed and I have written a better one with a gui now, just use it as an example.

Finally I developed a .desktop file which will autoload the example script when the login is ready. Copying that into the directory `/usr/share/gdm/autostart/LoginWindow/`.

To restart GDM I used this command as root: `service gdm stop && sleep 1 && service gdm start`

I used a VirtualBox machine which I communicated over via SSH in order to test this out, over and over, hacking away at how this could be done. You can try the same. The log files you should be watching are in `/var/log/gdm/:0-greeter.log` you’ll get all the stderr messages from your login screen in there as well as all the errors.

You can use DBus System connections on org.gnome.DisplayManager.Display to control the display and org.gnome.DisplayManager.UserManager to get lists of users, user information and events for when users are added and removed from the system, same goes for network manager and a bunch of other services running during the login session.

I’ll blog more, and perhaps video when I’m finished. For now, if you’re interested in login screen development for Gnome2 (I don’t know what they’re doing for Gnome3) then this will interest you.

I blogged last week about some of the issues with classic ubuntu in the up and coming Natty Narwhal release.

I’m happy to report that all the bugs were considered, well received and fixed. Happily for all of us who are stuck without unity because of GFX issues and all those who need a little more time to get comfortable. The alternative desktop is more classically classical than it was in the previous alpha release:

A big thank you to the developers for taking the bugs and getting them fixed before release. Also *huggles* and ice-cream.

I’ve been highly critical¹ of corporate copyright assignment policies, especially those that effect me personally. Canonical, one of those I’ve complained about, has been working to try and standardise the wording and formation of the contracts that you have to sign in order to assign copyright over.

This is called Project Harmony and it kicked off today an alpha release, which we can get involved with and try and fix and bug report.

To be fair to the process (and in hope that it can fix Canonical’s current utterly ghastly wording) I’ve put together a diagram so you can understand what the options are in the new alpha contract:

What is interesting is that while diagramming² , I could see the difference between the FSF’s³ assignment agreement (2.1 > iv) and Canonical current agreement (2.2 > v) and they do show up in stark contrast.

What are your thoughts on this project? Will it improve the situation with contributing to Canonical’s Unity, Mozilla’s Firefox or even the FSF’s Gnu project?

¹I’ve likened it to corporate theft, misappropriation of volunteer work and powerful coercion from the project maintainers project’s coherence. Similar to an optional serfdom.
²This isn’t a legal diagram, just an illustration to aid comprehension. I am not a lawyer, please check with your legal council on these matters.
³Interestingly I’ve just signed two FSF copyright assignment forms, hopefully I’ll be able to blog about what I’ve been up to with them soon.

Here we go, got the photos for the jam, look at how happy everyone is:

To celebrate the release of revision 16 of my Free Culture Tabloid sided poster, I’ve put together each section into it’s own US letter poster so that a multi-poster display can be created using all of the pieces.

Do you like the edits that have gone into each revision? Is the wording easy to understand and direct enough for public consumption? Please give me your thoughts in the comments below.

It looks like the Dell USA website has been updated and is now selling 2 models of Ubuntu laptop. The first is a 10 inch almost netbook which ships with Ubuntu 10.10 (so it’s likely to be a recent addition) and an older Latitude 13-N which comes with Ubuntu 9.10 (which shows it’s likely to be an older model that might not have been properly advertised on the website previously)

What is interesting is that while there are 2 models of Ubuntu laptop, there are 86 models of Windows 7 computer. Clearly showing how far we have to go in order to convince Dell to be more serious about it’s Ubuntu sales and perhaps how far we have to go to cross the chasm.

Your thoughts?