Docker on Gentoo

Finally got Docker running on my Gentoo desktop, after a couple of days of futzing with the kernel configuration. The most valuable information I found along the way was this blog post, which covered most of the kernel configuration. Small differences due to the passage of time: the main portage tree is at docker 0.7.1 and go 1.2 now. Small difference due to my following the path of least resistance: I built an AUFS kernel. Everything seems to be working smoothly, though I haven't pushed hard yet.

I hope I'm wrong about this

I've been spending a lot of time lately writing C (yay!) to be called from MATLAB (boo!). Something deep in my code was seg faulting, but I couldn't get close to it because MATLAB's got signal handlers set. Okay, fine, I'll set the handler for SIGSEGV to SIG_DFL and then I can look at the core file.

Getting rid of MATLAB's SIGSEGV handler leads to crash and dump within seconds, even if my code is just the signal() call. Which makes me think that there's something in MATLAB that's seg faulting more or less continuously, and they're putting the train back on the tracks every few seconds.

The grass is so very much greener over in NumPy/SciPy/NiPy land.

Punk languages, my ass

Something about this made me want to punch the guy in the face. I should be a sympathetic audience: C is always my second-favorite language (after the best available Lisp, whatever that is at the moment) and it's often exactly the right tool, because C is all about your being responsible for everything. (Kinda. Sorta. Less responsible for everything than you think, really.) But the argument here is so weak, and depends on such a weird view of what makes a language good, that my knuckles get to itching.

Also, assuming that there's something punk about C, anyone who thinks that ObjC (or, gods help us, C++) is punk too is the same sort of person who would call Green Day punk. Don't even get me started on f'n JavaScript.

Pushing square Java into a round hole

I don't know just what the Java gnomes were thinking the language would be good for, but it's clear that desktop applications was not on the list. One of my smaller complaints: the system/user preferences system is borked on Linux.

The general problem is that the JDK installer doesn't set up the preferences folder. There are a variety of symptoms and an assortment of cures posted around the intertubes. I don't know that I've completely solved the problem, but here's my best shot:

sudo mkdir /opt/sun-jdk-1.6.0.21/jre/.systemPrefs
sudo touch /opt/sun-jdk-1.6.0.21/jre/.systemPrefs/.system.lock
sudo touch /opt/sun-jdk-1.6.0.21/jre/.systemPrefs/.systemRootModFile
sudo chmod 666 /opt/sun-jdk-1.6.0.21/jre/.systemPrefs/.*
sudo chmod 777 /opt/sun-jdk-1.6.0.21/jre/.systemPrefs

I'm sure this could be smarter about security. Maybe in a later post.