Saturday, April 29, 2017


In Tribblix, it's a basic principle that I ship upstream software unmodified. I don't impose my own views on installation layout, nor do I customize it. Generally, I apply patches only to make stuff compile.

This means that what you see in Tribblix is exactly what the upstream author intended, and not some distro-specific bastardization of it.

It also makes my life easier, I don't have to maintain patches, and updating software is much easier if it's unmodified.

In particular, I use an absolutely vanilla illumos-gate. (For a long time it differed only in that I had the fix for 5188 applied, relevant because Tribblix actually uses SVR4 packaging, but now that's integrated I don't even need to do that.)

Again, this makes my life easier. (When you're maintaining a distro on your own in your spare time, making decisions that simplify your job is essential.)

But it also has another benefit: because I have no "special" features that I've added, I'm not tied to one particular version or variant or commit of illumos. Any version of illumos-gate will do just fine. When it comes time to make a release, I just clone the gate, build, and go.

What I could do, then, is build an instance of Tribblix atop some other fork of the gate. For example, illumos-omnios.

I did just that, built the gate (it needed a couple of changes to Makefiles because of the way that perl and snmp are slightly different in OmniOS than it is in Tribblix), created packages, built an ISO, booted and installed it in VirtualBox.

As expected, it just works.

But just demonstrating that it works isn't really the reason I wanted to do this. What I'm really after is the LX brand, which has been integrated into current OmniOS.

Installing an LX zone requires a Linux image. The original (Joyent) work was for their own deployment mechanism, using ZFS images. As soon as it was available in OmniOS the first thing I did was use tarballs, which OmniOS now supports. The easiest way to create a Linux image is to create a Docker container the way you like it, and then export it to a tarball. I did that for Alpine and installed a zone based on that.

Then you can do very simple things like:

# zlogin lx1 /bin/uname -a 
Linux lx1 4.4 BrandZ virtual linux x86_64 Linux

It's an attractive idea to simply use this as the base for the next Tribblix release. However, that requires illumos-omnios to be supported in the long term, which is currently at risk.

Wednesday, April 12, 2017

Noisy Tribblix

I've had a couple of Tribblix users ask me why audio doesn't work.

This was something I had noticed myself, and the reason was not that audio was in some way broken, but that the permissions on the audio devices were wrong - owned and only writeable by root.

Now I only wanted to actually get any audio out on fairly rare occasions, so a quick chown wasn't that much of an imposition. But it obviously needed fixing properly.

My assumption here is that most desktop users will be logging in through the SLiM login manager. So all I need to do is fix the permissions just before it calls setuid() to the logged in user. And then reset them back once the user is done.

Now, I could have made up a bunch of chowns myself, or written a helper. There's actually code in SLiM to call ConsoleKit - but I don't have ConsoleKit, and don't really see the need to maintain a port of it just for this.

But illumos already has the capability to do this, and the normal login mechanisms use it. There's code in libdevinfo that sets the permissions according to the rules laid out in the /etc/logindevperm file. So the code is really just a call to di_devperm_login() and di_devperm_logout(), and all is well.

This also fixed another irritating bug - I can now eject memory sticks as myself, without needing to be root.

The next thing that happens, of course, is that it doesn't take very long to realise that Twitter has a lot of videos that play automatically. So I'm sitting there and I can hear either the internal loudspeaker or my headphones warbling away.

So the next thing I need is a way to shut the thing up. Historically, I used the old CDE sdtaudiocontrol, which was pretty good. (In general, I detested CDE as a desktop, the mailer and calendar were decent enough for their time, and the audio control was the only other thing I used much.) I use Xfce as my desktop, it used to have xfce4-mixer but that's now unmaintained and deprecated (and I removed that as part of the migration from gstreamer-0.10 to gstreamer1). Which pretty much leaves the command line audio utilities in illumos, specifically audioctl. I've added the package so users who update will automatically get that as well.

The command

audioctl set-control volume 0

silences things, while

audioctl set-control volume 75

puts the volume back to normal. I've created aliases mute and unmute for those. A more sophisticated approach would be to save the volume and restore it afterwards, but this is enough for now.