Diary of a geek

[debian] Fixing some issues with changelogs.debian.net

Sun, 17 May 2015 14:42:00

I got an email last year pointing out a cosmetic issue with changelogs.debian.net. I think at the time of the email, the only problem was some bitrot in PHP's built-in server variables making some text appear incorrectly.

I duly added something to my TODO list to fix it, and it subsequently sat there for like 13 months. In the ensuing time, Debian changed some stuff, and my code started incorrectly handling a 302 as well, which actually broke it good and proper.

I finally got around to fixing it.

I also fixed a problem where sometimes there can be multiple entries in the Sources file for a package (switching to using api.ftp-master.debian.org would also address this), which caused sometimes caused an incorrect version of the changelog to be returned.

In the resulting tinkering, I learned about api.ftp-master.debian.org, which is totally awesome. I could stop maintaining and parsing a local copy of sid's Sources file, and just make a call to this instead.

Finally, I added linking to CVEs, because it was a quick thing to do, and adds value.

In light of api.ftp-master.debian.org, I'm very tempted to rewrite the redirector. The code is very old and hard for present-day Andrew to maintain, and I despise PHP. I'd rather write it in Python today, with some proper test coverage. I could also potentially host it on AppEngine instead of locally, just so I get some experience with AppEngine

It's also been suggested that I fold the changes into the changelog hosting on ftp-master.debian.org. I'm hesitant to do this, as it would require changing the output from plain text to HTML, which would mess up consumers of the plain text (like the current implementation of changelogs.debian.net)

[tech] LWN Chrome extension published

Wed, 13 May 2015 22:03:00

I finally got around to finishing off and publishing the LWN Chrome extension that I wrote a couple of months ago.

I received one piece of feedback from someone who read my blog via Planet Debian, but didn't appear to email me from a usable email address, so I'll respond to the criticisms here.

I wrote a Chrome extension because I use Google Chrome. To the best of my knowledge, it will work with Chromium as well, but as I've never used it, I can't really say for sure. I've chosen to licence the source under the Apache Licence, and make it freely available. So the extension is available to anyone who cares to download the source and "side load" it, if they don't want to use the Chrome Web Store.

As for whether a userscript would have done the job, maybe, but I have no experience with them.

Basically, I had an itch, and I scratched it, for the browser I choose to use, and I also chose to share it freely.

[tech] Honey, I wrote my first Chrome extension!

Sat, 07 Mar 2015 22:03:00

I love reading Linux Weekly News. It's a great source of high quality Linux and FOSS journalism, and I've been a subscriber for years.

One mild annoyance I have with the site is the way articles are cross-linked. All the article URIs are in the format /Article/531114/, which isn't particularly descriptive about that article's content.

When faced with an article that links to another article, with perhaps a word of anchor text, it's hard to tell if the new article is worth opening in a tab, is indeed already open in a tab, or has been previously read. (Yes, the "visited link" colour can help to a small degree, but even then, it doesn't tell you which previously read article it is).

This is what ~~God~~ the W3C invented the title attribute for.

Back in April 2011, I emailed Jonathan Corbet and asked if his content management system could just do this, but it was apparently a bit tricky, and it got filed in the "feature request" bucket.

I was sufficiently irritated by this deficiency last Monday, when doing some heavy reading on a topic, and so I decided to take matters into my own hands, and also learn how to write a Chrome Extension into the bargain.

I was delighted to have scratched the itch under 24 hours later and developed something that solved my particular problem - lwn4chrome I'm calling it.

I'm just finalising an icon for it, and then I'll have a stab at putting it in the Chrome Web Store as a freebie.

I might even have a crack at writing a Firefox extension as well for completeness, but I suspect the bulk of LWN's readership is using Chrome or Chromium.

[tech] A geek Dad goes to Kindergarten with a box full of Open Source and some vegetables

Mon, 08 Dec 2014 22:03:00

Zoe's Kindergarten encourages parents to come in and spend some time with the kids. I've heard reports of other parents coming in and doing baking with the kids or other activities at various times throughout the year.

Zoe and I had both wanted me to come in for something, but it had taken me until the last few weeks of the year to get my act together and do something.

I'd thought about coming in and doing some baking, but that seemed rather done to death already, and it's not like baking is really my thing, so I thought I'd do something technological. I just wracked my brains for something low effort and Kindergarten-age friendly.

The Kindergarten has a couple of eduss touch screens. They're just some sort of large-screen with a bunch of inputs and outputs on them. I think the Kindergarten mostly uses them for showing DVDs and hooking up a laptop and possibly doing something interactive on them.

As they had HDMI input, and my Raspberry Pi had HDMI output, it seemed like a no-brainer to do something using the Raspberry Pi. I also thought hooking up the MaKey MaKey to it would make for a more fun experience. I just needed to actually have it all do something, and that's where I hit a bit of a creative brick wall.

I thought I'd just hack something together where based on different inputs on the MaKey MaKey, a picture would get displayed and a sound played. Nothing fancy at all. I really struggled to get a picture displayed full screen in a time efficient manner. My Pi was running Raspbian, so it was relatively simple to configure LightDM to auto-login and auto-start something. I used triggerhappy to invoke a shell script, which took care of playing a sound and an image.

Playing a sound was easy. Displaying an image less so, especially if I wanted the image loaded fast. I really wanted to avoid having to execute an image viewer every time an input fired, because that would be just way too slow. I thought I'd found a suitable application in Geeqie, because it supported being out of band managed, but it's problem was it also responded to the inputs from the MaKey MaKey, so it became impossible to predictably display the right image with the right input.

So the night before I was supposed to go to Kindergarten, I was up beating my head against it, and decided to scrap it and go back to the drawing board. I was looking around for a Kindergarten-friendly game that used just the arrow keys, and I remembered the trusty old Frozen Bubble.

This ended up being absolutely perfect. It had enough flags to control automatic startup, so I could kick it straight into a dumbed-down full screen 1 player game (--fullscreen --solo --no-time-limit)

The kids absolutely loved it. They were cycled through in groups of four and all took turns having a little play. I brought a couple of heads of broccoli, a zucchini and a potato with me. I started out using the two broccoli as left and right and the zucchini to fire, but as it turns out, not all the kids were as good with the "left" and "right" as Zoe, so I swapped one of the broccoli for a potato and that made things a bit less ambiguous.

The responses from the kids were varied. Quite a few clearly had their minds blown and wanted to know how the broccoli was controlling something on the screen. Not all of them got the hang of the game play, but a lot did. Some picked it up after having a play and then watching other kids play and then came back for a more successful second attempt. Some weren't even sure what a zucchini was.

Overall, it was a very successful activity, and I'm glad I switched to Frozen Bubble, because what I'd originally had wouldn't have held up to the way the kids were using it. There was a lot of long holding/touching of the vegetables, which would have fired hundreds of repeat events, and just totally overwhelmed triggerhappy. Quite a few kids wanted to pick up and hold the vegetables instead of just touch them to send an event. As it was, the Pi struggled to play Frozen Bubble enough as it was.

The other lesson I learned pretty quickly was that an aluminium BBQ tray worked a lot better as the grounding point for the MaKey MaKey than having to tether an anti-static strap around each kid's ankle as they sat down in front of the screen. Once I switched to the tray, I could rotate kids through the activity much faster.

I just wish I was a bit more creative, or there were more Kindergarten-friendly arrow-key driven Linux applications out there, but I was happy with what I managed to hack together with a fairly minimal amount of effort.

[opinion] On Islamaphobia

Thu, 02 Oct 2014 16:45:00

It's taken me a while to get sufficiently riled up about Australia's current Islamaphobia outbreak, but it's been brewing in me for a couple of weeks.

For the record, I'm an Atheist, but I'll defend your right to practise your religion, just don't go pushing it on me, thank you very much. I'm also not a huge fan of Islam, because it does seem to lend itself to more violent extremism than other religions, and ISIS/ISIL/IS (whatever you want to call them) aren't doing Islam any favours at the moment. I'm against extremism of any stripes though. The Westboro Baptists are Christian extremists. They just don't go around killing people. I'm also not a big fan of the burqa, but again, I'll defend a Muslim woman's right to choose to wear one. They key point here is choice.

I got my carpets cleaned yesterday by an ethnic couple. I like accents, and I was trying to pick theirs. I thought they may have been Turkish. It turned out they were Kurdish. Whenever I hear "Kurd" I habitually stick "Bosnian" in front of it after the Bosnian War that happened in my childhood. Turns out I wasn't listening properly, and that was actually "Serb". Now I feel dumb, but I digress.

I got chatting with the lady while her husband did the work. I got a refresher on where most Kurds are/were (Northern Iraq) and we talked about Sunni versus Shia Islam, and how they differed. I learned a bit yesterday, and I'll have to have a proper read of the Wikipedia article I just linked to, because I suspect I'll learn a lot more.

We briefly talked about burqas, and she said that because they were Sunni, they were given the choice, and they chose not to wear it. That's the sort of Islam that I support. I suspect a lot of the women running around in burqas don't get a lot of say in it, but I don't think banning it outright is the right solution to that. Those women need to feel empowered enough to be able to cast off their burqas if that's what they want to do.

I completely agree that a woman in a burqa entering a secure place (for example Parliament House) needs to be identifiable (assuming that identification is verified for all entrants to Parliament House). If it's not, and they're worried about security, that's what the metal detectors are for. I've been to Dubai. I've seen how they handle women in burqas at passport control. This is an easily solvable problem. You don't have to treat burqa-clad women as second class citizens and stick them in a glass box. Or exclude them entirely.