WhiteRabbit's braindump

OmniPlugin

Sun, 16 May 2010 16:14:27 GMT

This plugin interfaces TiddlyWiki and OmniComment



config.macros.omni = {};

//

OmniComment

Sun, 02 May 2010 17:59:00 GMT

I am looking to replace Haloscan to have comments on here again. While I am at it I'd like to be able to get comments on any Web page.

After a couple hours of research, I just cannot find software that will do what I want, except one which requires MySQL (and I object to that).

So I'm starting a new project: OmniComment

ViewTemplate

Sun, 02 May 2010 14:11:00 GMT

<div class='toolbar' macro='toolbar -closeTiddler closeOthers +editTiddler permalink references jump'></div>
<div class='title' macro='view title'></div>
<div class='subtitle'><span macro='view modifier link'></span>, <span macro='view modified date DD MMM YYYY'></span> (created <span macro='view created date DD MMM YYYY'></span>)
<div class='tagging' macro='tagging'></div>
<div class='tagged' macro='tags'></div>
<div class='viewer' macro='view text wikified'></div>
</div>

<div class='tagClear'></div>

The problem with externalisation

Sun, 02 May 2010 14:03:00 GMT

I read much concern about how our privacy is threatened by all sorts of companies, such as Google (who knows everything about your secret desires) and Facebook (who knows all of your friends' birthdays).

My biggest concern relating to all these services is externalisation, which comes at the price of loss of control over the service or your data, or both. What happens if tomorrow Facebook decides to charge you 5 euro a month for their service? Chances are there would be an uproar at first, then most users would consider that it's too small a price to pay to worry about it. Yet they'd never have joined in the first place, had the service not been free in the first place.

Something similar happened to me recently: I used Haloscan to manage comments on this blog. Haloscan was free, easy to integrate and convenient: it did everything magically, filtered spam out, provided RSS feeds for comments and so on. And then inevitably one day they ran out of resources and slashed their free offers. I no longer have comments on my blog.

External services are like the dark side of the force: they are easier, faster, but ultimately not as powerful as doing things the right way, which is hosting everything for yourself. Only then do you know your service will surivive the stand of time. Well, as long as you pay for your ISP bill I guess.

Eben Moglen expressed somewhat similar thoughts (although mostly from the point of view of privacy, which is another facet to the control of your own data) in a very interesting, recent interview.

Posting e-mail

Sun, 02 May 2010 14:02:00 GMT

So, recently we ran into a problem at englishintoulouse.com: we have over 500 members, and our ISP, which I used as a smarthost, objects to our sending more than 200 e-mails a day. So, sending a newsletter becomes a two-day job, with the last people on the list getting the newsletter a lot later than they should.

I went through the pain of setting up my own outgoing SMTP server. It was simple 10 years ago when all SMTP servers just accepted your e-mail: thanks to spammers, it's become much harder and your setup needs to be a lot more precise if you want large ISPs to accept mail from your.

Here are the changes I made.

SPF

SPF (Sender Policy Framework) is a DNS record that documents who has the right to send e-mail for your domain. In our case, the IP address documented as A and MX record are allowed to send e-mail for us.

For MaraDNS, you add a line like this:

%       spf     'v=spf1 a mx ~all'
%       txt     'v=spf1 a mx ~all'

More details about SPF, including a script that builds the SPF record for you, are available on the SPF Web site.

ISP setup

Several large ISP (e.g. AOL) filter incoming mail depending on the emitting IP address.

Configure a reverse DNS with your ISP, so the RDNS is consistent with your domain (I am not sure this is totally useful).

Remove your residential IP from SpamHaus PBL: www.spanhaus.org, link "Remove IP Address". This lets most serious ISPs (Yahoo, Gmail, ...) receive your e-mail. Some other ISPs use a blacklist from Trend Micro. You'll also need to request being taken off their list.

AOL still won't listen, so use your ISP as smarthost just for them, adding to /etc/exim4/hubbed_hosts:

aol.com: smtp.free.fr

AOL also lets you set up a spam feedback loop, but I am not done with that yet.

Check your DNS setup

Another goal I had was to pass all of zonecheck(1) tests. This can be either run from their Web site or installed under Debian apt-get install zonecheck.

It pointed out that my DNS setup was klunky at best. So, what I need to do is tell my registrar that each of my domains has two nameservers, ns1.% and ns2.%, with the appropriate addresses. The registrar transmits that to the registry. The thing is, this will only work properly if your DNS is consistent with the registry, i.e. you have ns1.% and ns2.% A and NS records set up. In MaraDNS:

%       NS      ns1.%
%       NS      ns2.%

ns1.%           80.68.89.183
ns2.%           82.235.147.6

Then zonecheck insists that my servers should also serve TCP requests. In MaraDNS, in /etc/mararc:

tcp_convert_acl = "0.0.0.0/0"
tcp_convert_server = "80.68.89.183"

(with the appropriate IP address of course), and restart zoneserver (not maradns!).

Misc

You can test your e-mail system with

telnet relay-test.mail-abuse.org

This runs a series of security tests on the IP you're coming from and tells you the results. Ideal to find if you're accidently set up as an open relay.

O'Sushi Bar

Mon, 28 Sep 2009 10:40:00 GMT

This refers to O'Sushi Bar in town, we haven't tried any of the others, as it seems this actually is a chain.

We had high hopes for O'Sushi when it opened: it was small, and was the first Japanese restaurant that didn't emphasise sushi (which is a small part of Japanese cooking) or skewers (which we're not sure even exists in Japanese cooking :) ). We could get ramen, tonkatsu and few other traditional dishes at very affordable prices.

A year down the line, the restaurant has become quite big, raised its prices on all dishes, and now does a lot more sushi. It's got a cute sushi train that's actually done by boats floating on running water in a gully. Unfortunately, that kind of sushi is only available in a "all you can eat" formula, and is very, very average.

Altogether we've been disappointed.

O Sushi Bar, 30 r Gambetta, 05 61 21 98 64

Multi-criteria sorting in Perl

Fri, 28 Aug 2009 18:36:00 GMT

This is so simple I want to cry.

You know when you need to sort a list following several critiria? "Sort the files by type, then sort those that have the same type by name, then by size".

Perl's sort and comparison operators (cmp and <=>) come in handy:

 @sorted = sort { $a->type cmp $b->type or $a->name cmp $b->name or $a->size <=> $b->size} @list;

Assuming of course the objects in @list have type, name and size methods available.

This reads litteraly as "compare a and b's types, and if they're the same then compare their names, and then compare their sizes".

Of course you should never compare file sizes, because size doesn't matter.

Investing in real estate

Mon, 20 Apr 2009 19:28:00 GMT

A few days ago in a group conversation, there was a discussion on a number of bad things about France, and in particular on how it was a scandal that landlords had such a hard time getting rid of tenants that don't pay. I kind of put a damper on the conversation when I said that financially weak people should not invest in real estate, prompting questions on whether I considered people who are capable of buying a flat are financially weak. Although I felt I knew exactly what I meant, my arguments weren't ready. They are now.

Investment

The foundation of investment is to keep some of your money and lend it to someone else in order to make a profit. The capital you invest may get lost or go down in value, so investors associate a risk with any investment, and ask for higher yields for higher risk investments.

For example, investing in government-guaranteed bonds has a low risk of your capital disappearing, and has a low yield (in the order of 2% in France at the moment). Speculative investing in the Asian stock market can yield phenomenal returns (15%, sometimes more) but with a high risk of losing some of your capital (50% from 2000 to 2001 for example).

One of the basic rules of investing in the stock market (i.e. riskier investments) is that you should only invest money you can afford to lose. These words were actually literaly said by an investment advisor I met a long time ago during the dot-com boom. It sounds like reasonable advice.

Investing in Real estate

There is no reason to treat investing in real-estate any differently. This means that before investing in a flat, you need to assess your risk:

You may not find a tenant (reducing your ROI to 0%)
The tenant may not pay its rent (reducing your ROI to 0%)
The tenant may leave and cause extensive damage to the
flat (sending your ROI in the negative)

It is true that French law is strongly in favour of the tenants. However this is known ahead of time by prospective landlords, and should not come as a surprise.

According to my investment advisor, you should only invest what you can afford to lose. This means that:

if you can't find a tenant, it shouldn't be a problem,
if your tenant doesn't pay rent, it shouldn't be a problem,
if your tenant damages your flat, it shouldn't be a problem.

Basically it means that you can afford to lose the mortgage repayment. Otherwise you're exposing yourself to unacceptable risk (it's like borrowing money to invest in the Asian stock market). Being exposed to unacceptable risk is what I meant by being financially weak.

Converting WMA to OGG

Sat, 14 Mar 2009 09:16:00 GMT

At the moment I have no CD drive in my main Linux computer. As a result I can't use my favourite CD ripping program (which is jack, for the record). I have a CD drive on my work laptop which unfortunately runs WinXP, so it can only produce WMA.

So, I use Windows Media Player to extract the tracks to lossless WMA, then I copy them over to the Linux server and convert them as such:

 for i in * ; do mplayer -ao pcm "$i"; mv audiodump.wav "$i.wav"; done
 oggenc *.wav
 rm *.wma *.wav
 rename s/.wma// *

and I'm left with the same files as OGG instead of WMA. Straightforward, almost.

Securely running Firefox in a chroot

Fri, 13 Mar 2009 19:23:00 GMT

First problem: Debian stable's Firefox is old (2.x). Solution: install a chroot containing Sid, and install the latest version.

Thing is, it's a recurring problem in Debian; I had removed my chroot settings last time Sid turned to Stable, and I forgot how it was done. This time I'll document it.

Second problem: The Web browser is one of the most critical pieces of software you use. The main assets on a computer are its functions (the programs and servers you run) and your data.

My machine acts as a server, so it's got Apache: but Apache can only read files, not normally write to them. So a vulnerability in Apache alone won't compromise my system much.

On the other hand, my Web browser has the same rights as me, which means it can read or write any of my personal files. A vulnerability in Firefox is a threat to all my data.

Solution: run Firefox under a different user ID which has access to nothing.

So, let's do it.

I use schroot as a wrapper to chroot.

# Setup chroot
debootstrap sid sid

# Use same users as main system
cd sid/etc
rm passwd; ln /etc/passwd .
rm shadow; ln /etc/shadow .
rm group; ln /etc/group .
ln /etc/hosts .

# Install Firefox
cd ..
chroot .
apt-get update
apt-get install iceweasel

Now outside the chroot we add the user (which automatically gets added to the chroot as well) and install schroot:

adduser me_www
apt-get install schroot
vi /etc/schoot/schroot.conf
<< configure >>

For some reason X forwarding won't work if the chroot doesn't share the same /tmp as the main system (this doesn't totally make sense to me) so we add this to {/etc/fstab}:

/home           /root/chroot/sid/home/ none bind 0 2
/dev            /root/chroot/sid/dev none bind 0 2
/tmp            /root/chroot/sid/tmp none bind 0 1
/sys            /root/chroot/sid/sys none bind 0 1

Don't forget to mount all that ({mount -a}) then we can start Firefox, in the chroot, under the new user ID:

schroot -u me_www -c sid -- iceweasel --display $DISPLAY

Simple, innit?

On Genetically Modified Organisms

Wed, 14 Jan 2009 14:41:00 GMT

A good article from a genetician commenting on the fears about GMO. Very moderate and reasonable. Except for the fact that it's in French.

Yakiyori

Sun, 16 Nov 2008 09:16:00 GMT

A small japanese restaurant. It's easy to get lost on the way, so make sure you have a map of Colomiers. The service is very slow, so don't plan to go to the movies afterwards. It's the best sushi we've tried in and around Toulouse. Budget about 35EUR a head.

Yakiyori: 14 r Prat, Colomiers, 05 61 15 79 21

Our new address

Sun, 16 Nov 2008 09:12:00 GMT

We have recently moved to the suburbs of Toulouse. At our housewarming party a friend mentionned that my blog wasn't up to date. I guess he meant I said nothing about the move. So there: our new address is 82.235.147.6. Of course if you use DNS, you don't need to know that.

Dalle et Pepie

Sun, 16 Nov 2008 09:10:00 GMT

A pretty little restaurant in Arnaud-Bernard: the room sits about 20 to 30 people. The walls are all bricks and Garonne stones. Service is informal and friendly, and the food comes from Lyon: escargots, boudin, quenelles and so on, all excellent. Dinner will cost you about 25EUR a head.

Dalle et Pepie, 31, rue de la chaine, Toulouse, 05 61 21 55 33

La Forge

Sun, 16 Nov 2008 09:10:00 GMT

La Forge is a restaurant from another world. It's a restaurant set in a pretty red brick building in a small village twenty minutes out of Toulouse. The tables are set around a huge fireplace. It's altogether a rather nice place.

Cooking is very traditional southern French: Expect foie gras, duck, and so on (their foie gras in particular is excellent). Prices are very reasonable, with dinner set menus around 20EUR.

It's only open on friday night, saturaday lunch and dinner, and sunday lunch. Cards are not accepted, so come with cheque books or cash.

La Forge: Lavalette. 05 61 84 76 00

Linutop based computer?

Sat, 13 Sep 2008 12:34:00 GMT

I was telling Narelle about Linutop computers and how they were pretty cool, but too expensive for they are when you can get a big computer for 350EUR, and that Linutop's pretty much force you to have a server of some kind anyway. She came up with an interesting idea: with an external USB disc, you actually have a full computer.

I'll track my research on the topic of 'superlight, super-silent' computers here.

Linutop 1 considered too small (256Mb not really enough for Firefox (what about FF3?))
Linutop 2: 333EUR incl VAT

IDE-USB enclosure: 20USD or 14EUR or a better one at 20EUR
Disc: 500GB for 100EUR

Or:
500GB USB disc: 100EUR or 93EUR

An alternative to the USB enclosure would be to actually get a dedicated disc server such as this Quad-disc NAS. What's interesting here is the ability to scale: get one NAS with 500GB then several Linutops working off the same storage.

EDIT 13SEP2008: An alternative would be a FitPC which has an internal disc for a similar price range.

Reason and Faith

Fri, 12 Sep 2008 06:18:00 GMT

Yesterday I was listening to the radio and heard some goon of the pope talk about his highness' philosophical greatness. Apparently the pope is visiting France and that's worth ignoring all the pledges of laicity written in French law.

So, what's the summary of his highness Palpatine? He seems to be trying to reconcile reason and faith. He reasons that Pure Reason, i.e. reason without faith, leads to scientism and corruption of everything, with, like, the atomic bomb and genetic engineering (and abortion, presumably). Holy crap, isn't that "Science sans conscience n'est que ruine de l'ame" (Rabelais, five centuries ago)? Way to go, thinker!

And at the other end of the spectrum, is Pure Faith, which is also bad because that's what those evil islamists are doing. Lucky catholics don't believe too much, eh?

The argument of reason is laughable. Anyone who exercises reason should see that the atomic bomb is not a good thing, and among the reasons to avoid GMO, none are religious and all are related to actual, reasonable reasons (which are not linked to profit: just because it's outside the scope of capitalist reason, doesn't means it's outside of the scope of Reason).

It just blows my mind that this sort of argument is still going around. Faith, by definition, has nothing to do with reason, and vice-versa: the minute I uncritically believe something that is told to me, I stop using reason. I guess that's just too hard to reconcile in the head of a pope.

La Cabane de L'aiguillon

Tue, 05 Aug 2008 11:17:00 GMT

This is a paradise for the oyster lover: set directly in the production place, a few tables are set under a big vine and you'll get your pick of locally produced oysters. The people there are very nice, and you can see the work of the oyster farm while enjoying them with a glass of white and bread and butter. Among the oysters we tried around Arcachon, theirs also seem to be the best: clear, healthy-looking, appetizing. And cheap. And goooooood.

La Cabane de l'Aiguillon
Boulevard Pierre Loti
33120 Arcachon
05 56 54 88 20

Great Business ideas

Mon, 04 Aug 2008 14:19:00 GMT

I have lots of ideas for businesses, which I usually have no intention of following up (because of lack of ambition, laziness and so on). I'll give them to the world. If you make a fortune using my ideas, consider giving me a bottle of wine or something.

Breakfast delivery route: Most people are too busy/lazy to get up in the morning and get fresh bread rolls or croissants from their local bakeries (this is a problem in France — other countries may not even have bakeries at all). The idea is to get a delivery service to bring fresh croissants to people in the morning. Basically this is the same as the old milk delivery or paper routes. Milk deliveries have disappeared not so much because it's too expensive, but because the availability of fridges has made them useless. Although bread machines do exist, they don't make croissants, and a good baker makes better bread (well, that's not true everywhere — a scary number of bakers make bread that's worse than supermarkets). I reckon it would work.

Wine bank: You bought all that very nice wine from Bordeaux, and you were told it's best to age it another three to ten years. Wine matures best at constant temperature of about 17C, preferably with high humidity. Clearly you can't keep those bottles in your flat (it's clutter, and temperature in flats tend to vary drastically), and so-called wine fridges are not a real solution (you're not going to buy a 100-bottle fridge, put that in your bar, and fill it with bottles you can't touch for three years) (okay, maybe you are going to do that, in which case my service won't interest you). The solution is to take your wine to the bank: it's just like a safe deposit box, you pay a small fee per bottle and per year kept and the temperature and humidity is guaranteed.

13 April 2008

Tue, 15 Apr 2008 09:27:00 GMT

"Your cat fell off the balcony," kids coming up the stairs told us. "What? No, he's right over here." "No, he's down there he fell off!" Our cat comes over to see what's going on. "See, he's right here." "Oh." "Oh, a cat fell off the balcony".

Sure enough, we could see it down there on the floor, laying and looking around. We went downstairs to see if we could help.

It was the cat from the neighbours upstairs, a small, young cat that was into extreme acrobatics. One afternoon I found him in front of our door, and he escaped into our flat. I spent ten minutes trying to get him, as he jumped from the balcony to the office window (we're on the sixth floor) and balanced on the railing, all that in high wind.

On that sunny Sunday, he was laying on the floor, in the corner of a garage door, just under the balconies. He was looking around as we approached. Blood was coming out of his mouth and eyes. After a minute not knowing what to do, Narelle went back up to see if she could find the owners, or call or a vet, or something.

I stayed with him and laid my hand on his neck. He cried blood. He was fighting to breathe for all the blood in his mouth and windpipe and lungs. I felt powerless and sad. I could hear the gurgle of the blood down in his throat. He'd pooed himself. That's the smell of death, a mixture of blood and shit.

Later the owners came and I moved the cat in its carrier. I didn't think he stood a chance after that fall from the 7th floor down on to concrete, but you've got to do what you've got to do.

That night the neighbours came around to let us know the vet gave him morphine, then found he had perforated lungs, perforated palate. He was put to sleep.

Shit.