Stefano Rivera (Posts about clug)

Videos up

Stefano Rivera — Fri, 03 Oct 2008 18:43:11 GMT

Administravia: Just uploaded a pile of videos:

Geekdinner Sep 2008
GStreamer CLUG Talk
PEP3118 CTPUG Talk (this one has been sitting around for a while)
Mayavi CTPUG Talk

Also, I changed a few feeds on CLUG Park from RSS to Atom, so sorry about any RSS-reader-spamming.

Political Compass

Stefano Rivera — Wed, 24 Sep 2008 21:02:16 GMT

I'm not an Internet-meme person, but #clug has been rather into the Political Compass Tests recently (Thanks to Michael Gorven's graphing of our scores).

Those of us in the sensible quadrant of the graph are rather worried about the distance that some people are from us. I mean, they must be total nutters :-)

To help them understand the incorrectness of their ways, Jonathan suggested that we write up our choices and reasoning. I haven't read anyone else's reasoning yet, but here is my reasoning for each choice in the test. It might well be different to the last time I did it, but that's probably caused by me thinking about my choices rather than the embarrassment of publishing them. (I'm right, remember). On #clug, we acknowledge that peoples' views change and keep a history of past scores, although the graph doesn't display that (nudge nudge Michael).

If you haven't done this test, and are interested, maybe take it before you read any further. It'll take you less than half an hour, and promises a little food for thought.

Page 1: Just a few propositions to start with, concerning - no less - how you see the country and the world.

If economic globalisation is inevitable, it should primarily serve humanity rather than the interests of trans-national corporations.: Agree - Yes it should, but if globalisation is inevitable, how can we make it serve specific goals. It'll do what it wants to do. I go with agree on principle, but with the understanding that there isn't much we can do to make this a reality.
I'd always support my country, whether it was right or wrong.: Strongly Disagree - No way. While we all have a bit of national pride I make my own decisions. I'd seriously consider emigrating if our government were to go mad and started invading random nations (no Lesotho doesn't count).
No one chooses his or her country of birth, so it's foolish to be proud of it.: Agree - Yes, you're born where you are born, and you are welcome to national pride. The values we hold that lead to such a pride are in a large part determined by our up-bringing, we can't self-bootstrap. I'm an Italian citizen, but I've never spent more than a month in the country (and on that visit, I was barred from leaving the country because they wanted me for national service).
Our race has many superior qualities, compared with other races.: Strongly Disagree - What? Let's leave that one there.
The enemy of my enemy is my friend.: Disagree - I don't pick enemies easily, so the enemy of my enemy is unlikely to be an enemy. I won't align myself with someone unless our disagreements have common ground.
Military action that defies international law is sometimes justified.: Strongly Disagree - It might be justified that doesn't mean I'll agree with it. It's still illegal. If there is cause for such action, International Law should probably be amended.
There is now a worrying fusion of information and entertainment.: Agree - Not a well phrased question. Information and entertainment go hand in hand well, we all know how boring bland writing is. But there is a worrying trend in current media toward sensationalism -- this can readily be considered entertainment.

Page 2: Now, the economy. We're talking attitudes here, not the FTSE index.

People are ultimately divided more by class than by nationality.: Strongly Agree - Nationality doesn't matter that much these days. Class still appears to.
Controlling inflation is more important than controlling unemployment.: Agree - I stand under correction here, I'm not an economist. I'd imagine that they both need to be kept under control, but that letting inflation get out of control will quickly lead to bigger unemployment problems.
Because corporations cannot be trusted to voluntarily protect the environment, they require regulation.: Strongly Agree - Most large corporations care a lot more about their shareholders returns than the environment. And many of the worst environmental disasters can be pinned on corporations chasing profit.
"from each according to his ability, to each according to his need" is a fundamentally good idea.: Disagree - It's a nice thought, but actually getting this out of people is non-trivial. It requires more trust than free market does.
It's a sad reflection on our society that something as basic as drinking water is now a bottled, branded consumer product.: Agree - I never have a water bottle on me when I need it, and drinking fountains are way too scarce. Dare I even question how one gets brand loyalty in that market?
Land shouldn't be a commodity to be bought and sold.: Strongly Disagree - Well how should it be worked then? Considering the current housing market, land is really important to people.
It is regrettable that many personal fortunes are made by people who simply manipulate money and contribute nothing to their society.: Agree - Regrettable, but inevitable. Whatever works for them. Fortunately they can do that and still be interesting people.
Protectionism is sometimes necessary in trade.: Strongly Agree - I think history shows that. "Sometimes" is a useful qualifier there :-)
The only social responsibility of a company should be to deliver a profit to its shareholders.: Strongly Disagree - How is that a social responsibility? That's a financial responsibility.
The rich are too highly taxed.: Disagree - Again, IANAE. The rich are pretty good at dodging tax anyway, but high tax on the rich is bad for the economy.
Those with the ability to pay should have the right to higher standards of medical care.: Strongly Agree - Why not? Worst case scenario, it can help subsidise health-care and inject money into the system.
Governments should penalise businesses that mislead the public.: Strongly Agree - People trust large companies. Sad but true.
A genuine free market requires restrictions on the ability of predator multinationals to create monopolies.: Strongly Agree - Monopolies don't help anyone but themselves (and that only in the short-term). They certainly don't lead to a free-er market.
The freer the market, the freer the people.: Disagree - To a small extent, yes. highly controlled markets are don't give their citizens much choice in business, beyond that, I disagree.

Page 3: Now a look at some of your personal social values …

Abortion, when the woman's life is not threatened, should always be illegal.: Strongly Disagree- No need to compound already-painful mistakes.
All authority should be questioned.: Strongly Agree - We had a big argument about this one at CLUG dinner this week. I think Jeremy (who was arguing against me) was interpreting this question incorrectly.
An eye for an eye and a tooth for a tooth.: Strongly Disagree - How does that help anyone?
Taxpayers should not be expected to prop up any theatres or museums that cannot survive on a commercial basis.: Strongly Disagree - Many things that are supported by the treasury aren't commercially viable. Of course some unprofitable theatres and museums aren't worth propping-up, but we trust that such decisions can be made.
Schools should not make classroom attendance compulsory.: Strongly Disagree - Children cannot be expected to make such a decision for themselves, and there are some screwed-up parents out there who shouldn't be given such a powerful way to disadvantage their children.
All people have their rights, but it is better for all of us that different sorts of people should keep to their own kind.: Strongly Disagree - If, as a nation, we give people rights then we have to respect those rights. Otherwise emigrate.
Good parents sometimes have to spank their children.: Agree - IANAP. I think this is true, although it can be kept down to a very small value of sometimes.
It's natural for children to keep some secrets from their parents.: Strongly Agree - It's a nasty world out there, and people have to learn how to protect themselves. Also, this goes both ways, parents keep secrets from their children. Quite simply I think it would be unhealthy not to agree with this statement.
Possessing marijuana for personal use should not be a criminal offence.: Agree - Illegalising drugs doesn't help anything, although like many legal things marijuana can be harmful.
The prime function of schooling should be to equip the future generation to find jobs.: Disagree - Call me an idealist, but I'd like to think of schooling as more than that. It should teach you how to be a human (by our definition), and should give you the tools to discover and reach for ambitions. These may lead to jobs.
People with serious inheritable disabilities should not be allowed to reproduce.: Strongly Disagree - I don't think the argument for this is remotely compelling enough to impose such a restriction.
The most important thing for children to learn is to accept discipline.: Strongly Disagree - What an awful summary of childhood. Anyway, I don't know if I did learn that.
There are no savage and civilised peoples; there are only different cultures.: Agree - I can only agree with this, not strongly, as our civilisation rests on a certain amount of "civilisation" in the population. So we have to draw lines somewhere. We call the other side of that line "savages".
Those who are able to work, and refuse the opportunity, should not expect society's support.: Agree - Depends on what they are doing (persuits of knowledge have to be exempted), but our society does require that, yes. Personally, when I'm not working on something I feel unhappy so I'm biased towards working.
When you are troubled, it's better not to think about it, but to keep busy with more cheerful things.: Agree - Very loaded question, entirely depends on what the trouble is. For me, it's often procrastination which requires work to push through it.
First-generation immigrants can never be fully integrated within their new country.: Disagree - This is quite possibly true for many migrants, but there are many counter-examples. Many countries are very similar, and migration doesn't necessarily mean that much change.
What's good for the most successful corporations is always, ultimately, good for all of us.: Strongly Disagree - Corporations are successful in their own niches, such things are usually heavily biased towards the situation and against the general good.
No broadcasting institution, however independent its content, should receive public funding.: Strongly Disagree - The achievements of the BBC (for all its foibles) are a great counter-example here.

Page 4: … and how you see the wider society.

Our civil liberties are being excessively curbed in the name of counter-terrorism.: Strongly Agree - And it doesn't seem to be helping, either. Fortunately this hasn't reared its head too much in South Africa yet.
A significant advantage of a one-party state is that it avoids all the arguments that delay progress in a democratic political system.: Disagree - We've seen in South Africa that a virtually one-party state can still have such arguments, they don't delay progress, and the arguers quickly get branded as whiners. (Btw, I support the DA)
Although the electronic age makes official surveillance easier, only wrongdoers need to be worried.: Strongly Disagree - History shows this to be incorrect. Such powers get abused.
The death penalty should be an option for the most serious crimes.: Strongly Disagree - No matter how bad the prison system is, lets assume that everyone has the possibility of rehabilitation, unless there is something very psychologically wrong with them (in which case they probably wouldn't and shouldn't be eligible anyway).
In a civilised society, one must always have people above to be obeyed and people below to be commanded.: Disagree - The people who are to be obeyed must be subject to the same law.
Abstract art that doesn't represent anything shouldn't be considered art at all.: Disagree - "But is it art?" Why should art involve representations. Music doesn't. There comes a point when art stops, but we all draw that line in different places.
In criminal justice, punishment should be more important than rehabilitation.: Strongly Disagree - People are remarkably resilient to punishment, and no it doesn't seem to help, only the threat of it helps.
It is a waste of time to try to rehabilitate some criminals.: Disagree - It probably is, but can you pick those criminals out for me?
The businessperson and the manufacturer are more important than the writer and the artist.: Strongly Disagree - Not in my books.
Mothers may have careers, but their first duty is to be homemakers.: Strongly Disagree - I'm happy with a father being a home-maker. And I'm happy with working parents, although obviously they shouldn't neglect their children.
Multinational companies are unethically exploiting the plant genetic resources of developing countries.: Agree - Yes some are, although this is a very broad statement.
Making peace with the establishment is an important aspect of maturity.: Agree - I don't know if it's important so much as inevitable. Certain parts of the establishment are welcome to be overthrown in my books.

Page 5: If you got through that okay, you'll find these propositions on religion a breeze.

Astrology accurately explains many things.: Strongly Disagree - Not sufficiently for me.
You cannot be moral without being religious.: Strongly Disagree - This one probably depends on definitions.
Charity is better than social security as a means of helping the genuinely disadvantaged.: Disagree - I don't really know what to say here, but I can't support that statement.
Some people are naturally unlucky.: Agree - Some people have really bad things happen to them. It sucks. That doesn't mean that they attract bad luck.
It is important that my child's school instills religious values.: Strongly Disagree - No thanks.

Page 6: Finally, a look at sex.

Sex outside marriage is usually immoral.: Strongly Disagree - Definitions strike again.
A same sex couple in a stable, loving relationship, should not be excluded from the possibility of child adoption.: Strongly Agree - Why not? There are many things that can be bad for a child's childhood, the lack of a specific gender in a parental role is common already. What other arguments are there against this?
Pornography, depicting consenting adults, should be legal for the adult population.: Strongly Agree - I've got nothing against this.
What goes on in a private bedroom between consenting adults is no business of the state.: Strongly Agree - I don't think there is one set of morals that fits all.
No one can feel naturally homosexual.: Strongly Disagree - I wouldn't know, I'm under guidance on this one.
These days openness about sex has gone too far.: Disagree - In many areas it probably hasn't gone far enough.

The end: My current political compass:

Economic Left/Right: -4.62
Social Libertarian/Authoritarian: -6.26

I've moved fractionally up since I last took the test (-4.62, -6.41) that's it. Now I can go and read other peoples' justifications for their choices.

Aggregator noise and growth

Stefano Rivera — Mon, 21 Jan 2008 11:23:53 GMT

For the bloggers on Clug Park, who don't deign to follow clug-chat or #clug, there have been recent discussions about creating a separate, filtered park for readers with less free time.

The problem is basically that some people post a lot of posts. Sometimes as much as half of the park is dominated by one poster. While this isn't a problem per se (some people clearly have more blogging time), it means readers have more to wade through, and can feel swamped my the prolific posters. Many would prefer something with a higher signal-to-noise ratio, and lower volume.

As communities grow, the signal-to-noise ratio often suffers, and the higher volume is too much for some readers. Rather than lose the readers, we'd like to provide an alternative, filtered park. It's currently being prepared here. Personally, I'll still use the old park, as will many other prolific RSS-feed-followers.

What we need is for all the CLUG Parkers to create a "technical" tag, and tag all relevant posts as such. Then send me the URL of your new tag, and I'll include it in the "park-tech". (Or assure me that you don't post too prolifically, and only tech-related posts, and we'll carry your entire feed).

Lets see if we can make it work.

Some Wiki Updates

Stefano Rivera — Sat, 05 Jan 2008 20:55:05 GMT

I've just spent an afternoon and evening on the local wikis I look after: CLUG, Freedom Toaster, and GeekDinner.

They've all been upgraded to MediaWiki 1.11.0, with reCAPTCHA on sign-ups, and OpenID support.

If you are a user of one of these wikis, you can go to Special:OpenIDConvert (CLUG, FT, GeekDinner) to add OpenID to your account.

In the past, the CLUG wiki has had minimal wikispam, because we thought up some clever regexes, that blocked spammers from editing. However spammers would still sign up, before they tried to edit. This has left the wiki with over a thousand bogous users. Not that that is a problem in itself, but it becomes a bore when you want to guess somebody's wikiname to give them "Bureaucrat" status for example.

So jerith talked himself into coding up a quick SQL query to find all these bogus users, and a python script to remove them. Any history they've had has been assigned to the "Spammer" user, and they have been wiped from the wiki. If, in our zealousness, we've deleted any legitimate users who've simply never edited the wiki, we apologise. Maybe if you contribute something, it won't happen again... :-)

And I thought our Ubuntu mirroring was a success

Stefano Rivera — Fri, 19 Oct 2007 13:41:42 GMT

Due to archive.ubuntu.com's saturated links atm, I switched to using mirror.ac.za as our upstream, but forgot to take their different URL scheme into account. We don't use rsync's --max-delete option on debian mirrors, so voom, our entire ubuntu archive mirror vanished. I'm resyncing it UWC, who we have a 10Mbps wireless link to...

CLUG Talk videos

Stefano Rivera — Wed, 10 Oct 2007 11:22:24 GMT

CLUG is one of the more active LUGs around, and has had fortnightly meetings with technical talks consistently since at least 1999 (the extent of our records, and my involvement).

While this heritage is a testament to a strong LUG, there are only about 20 people who regularly attend meetings, and thus get the benefit of these talks. With a LUG membership of around 800 (my best estimate from mailing list figures), this is a tiny fraction of our community. People who can't make it have been requesting videos of talks for a while, and recently Jonathan Carter brought his camera, and we started playing with videoing them. He has been stuck in Johannesburg for a few weeks and left me his camera, so I've been playing around with encoding.

So far, the lessens learned:

Video quality: A camera, high up at the back of the room produces reasonable, compressible video without having to have someone pan around following the presenter.
But the built-in microphones on a cheap camera just aren't effective at that range (especially when you've got a quiet speaker).
Audience questions are hard to record.
Audio editing is do-able, and necessary. But so far, we haven't ventured into video editing (on linux, this isn't trivial).
You can't normally read all the slides (or demos) with SD video. At full PAL resolution, most slides are legible. Screen-capture is an option, but most presenters make their slides available, which is far more bandwidth efficient.

Our progress so far is these procedures, and these videos: UK, ZA. We are using Ogg/Vorbis/Theora, and 3 different qualities of video. The three qualities are overkill, but I'm still experimenting with settings. I'd like some feedback - especially from a codec expert :-)

PHP4 for feisty - pbuilder for beginners

Stefano Rivera — Sun, 10 Jun 2007 20:40:36 GMT

I helped Robbster out on #clug today, building php4 for feisty (it's been dropped after edgy, in favour of php5). If you want to install it, don't care about security holes, and want to use the debs I created, add this line to your apt sources list, and go wild:

deb http://ftp.leg.uct.ac.za/pub/stuff/tmp/php4-feisty ./

If on the other hand you want to know how to do it (so when the next PHP security hole appears tomorrow, you can build the latest version yourself), read on:

I've never used pbuilder before, so it was fun:

# aptitude install pbuilder

Edit /etc/pbuilderrc to point to your closest mirror, and uncomment the COMPONENTSline (so that you get universe included)

# pbuilder create

Now pbuilder is ready for work. Get the latest sources from debian (Download those 3 files at the end, dsc, orig.tar.gz and diff)

# pbuilder build *.dsc

Sit back and watch...

When it's done, you probably want to create a trivial repository of your debs:

# cd /var/cache/pbuilder/result/; dpkg-scanpackages . /dev/null | gzip -c -9 > Packages.gz

Then add this to your sources.list

deb file:///var/cache/pbuilder/result/ ./

Wohoo. Remember to watch out for those security holes...

Sarge -> Etch Upgrade and apache2

Stefano Rivera — Fri, 04 May 2007 20:28:49 GMT

Thanks to Debian bug 407171, if you had mod_proxy installed in apache2, and upgrade to etch, it'll also install mod_disk_cache, which means your /var partition is going to fill up quite quickly.

This happened to 2 CLUG servers.

I don't think this is the correct behaviour, and I'm even more suprised to see that it the appearance of the bug is documented in a bug-report.

etch upgrades

Stefano Rivera — Tue, 10 Apr 2007 12:37:56 GMT

I've done etch upgrades in the past (i.e. before etch came out), and they were sometimes quite hairy. Especially the transition from ssh to openssh-server and openssh-client. I had a few broken upgrades...

Since etch has come out, I've been upgraded a few machines, and it's a piece of cake. In fact the CLUG webserver and backup-server have been upgraded.

My servers tend to use custom kernels without initrds, so upgrading is quite simple. The release notes seem to cover it pretty well. There are only a couple of gotchas I've had:

Upgrade vim with an aptitude install vim before you do any dist-upgrading. Personally, I like to use vimdiff for configuration file changes. This means I can keep the configuration file format and comments of the latest package, and my configuration changes from when the machine was originally set up. If vim is half installed, you can't run vimdiff...

When you are done, you might need to purge hotplug:

# aptitude purge hotplug

You can also remove non-US from your sources.list.

CLUG Park

Stefano Rivera — Tue, 13 Mar 2007 15:00:26 GMT

I've spent some time beefing up CLUG Park.

All the people who seem clueless about making avatars of the correct dimensions (ahem Rafiq), or cropping all the uncessary transparency around their avatar, I've sorted them out.

I've also switched us from Planet 2.0, to Planet Venus. This allows us to do funky things like filters (for you geeks with nasty RSS feeds). It also partitions out the theme far better, and above all does multi-threaded RSS harvesting.

Is anyone is keen on a tech-only (or CLUG-only) CLUG park, where we limit the subscriptions down to posts about CLUG or technology (using category RSS feeds), let me know, we can easily do this. While some of us like to read all about what CLUG Park members are up to, others probably only want to read tech-related articles?