Technical Ramblings

So, for the first time this weekend, I’m on a network where outgoing mail on port 25 is blocked. How annoying.

I use a number of mail servers in a number of different ways. Typically, when on one of my Linux boxes (zeus or athena) I’ll send mail directly from those servers by using a localhost Postfix installation, and no smart or relay hosts. I don’t really see a need for my ISP to see my mail, and doing it this way is the default setup for most Linux distros that I’m aware of.

If I’m someplace that doesn’t have a mail server (ie the powerbook, creusa, or the mac mini, hermes), I use athena as a mail host, on which I have installed SASL authentication. Athena is set up to accept mail in a couple cases:

1. Mail from local network. This includes all the IPs in my block on Sagonet.
2. SASL Authenticated users: This users password authentication against the local mail database to check users who can login to the server to send mail.

As such, the server is protected against being an open relay (so long as I don’t get a spammer on the local machine, but I don’t think that’s going to be the case), and I like having it there as a backup for when other mail servers fail me. wedu’s mail uses POP before SMTP for authentication, which is all well and good, but can be a pain since the logs are reset at :45 past the hour, and if you try and send mail right after that, you get a nice “Relay denied” message.

In any case, I tried to send mail this morning via crschmidt.net… and got a timeout. Tried getting there from here, no go. Panicked a bit, since this is my main mail server, and if it’s down, that’s a bad thing. Tested it from zeus: no problems. Tested it locally: no problems. Tried going to another port 25… problems. So it’s on the Ameritech end. Great.

Set up an ssh tunnel: ssh -L 25:localhost:25 crschmidt@crschmidt.net. Set up a server in Mail.app as localhost port 25. Forward my mail. Sigh at Ameritech. Bitch in weblog. And the circle of life continues.

I know that I’m far too lazy to actually describe my images. I never do it. I write tools to help me, and I still don’t. So, my goal is to use tools which do it for me. With Masahide’s EXIF tools, flickr, and flickr2rdf, I can do this, with a little fudging to get the output to flow together better.

I have a lot of photos to describe, and I was going to get to work on it, when I reached for my keyboard… and found the cat laying on it. So, I switched to the other computer (zeus, rather than hermes) and got to work, creating a SPARQL interface for my photos. Maybe if I can search them, I’ll actually describe them.

I haven’t done a whole lot yet, but the start of my work is in place, with a nice SPARQL query against it. Of course, so far there’s only one photo, but this example should get you started, and if you care, you can check out the data to get you started.

Search My Photos – the crschmidt.net album organization service.

Recently, I moved most of my serving to a colocated machine, so I finally have a “Testing” machine and a “stable” machine, leaving me more free to play around locally. This has led to me installing a Rasqal nightly release and installing it, in an attempt to get the newer SPARQL query syntax working in my RDF bot, so that I can test query type detection and the like.

I had no problems installing it: very simple, just download the nightly, ./configure, make, make install. I got it working in my local “julietest”, although I’m waiting until the next release before I consider installing it on the remote server.

I got it working in PHP from the command line, no problems.

However, no matter what I do, the web version still seems to be using the old query syntax, and I don’t have any clue why. If you go to http://zeus.crschmidt.net/julie/sparql, you can test it out, and it only returns data if you use the old query format. However, if I copy the same script locally, and run the exact same query, it doesn’t work, requiring the new format.

I don’t understand it, and I don’t know if anyone else does either. The PHP in Apache2 and CLI both have almost exactly the same phpinfo(), they both have the same extension directory, and there isn’t a second copy of redland.so for the Apache version to load anyway! If anyone has run into this problem before and knows how to fix it, I’d appreciate it, because right now I’ve given up and am waiting for a release before I debug further.

(This post brought to you in part by the effort to bump all of Danny’s off of PlanetRDF while he’s on vaccation. ;))

Yesterday, after some discussion regarding Bluemoon (currently offline, LiveJournal syndicated copy available at livejournal temporarily), the idea of a “Planet Swhack” was brought up: an aggregated collection of the weblogs of members of #swhack, much similar to the many other planets run by the Planet Planet software or like Planet RDF, run off the Chumpalogica aggregator.

So, yesterday, I set it up. AaronSw controls Swhack DNS, and wasn’t around at the same time as me at any point, so I set up as a temporary URI to demonstrate it. Picked up some bloggers, and set up the stylesheet to be the same as my other Planet, PlanetMobile. Tonight, as I was preparing to ask AaronSw to set up DNS for Planet Swhack, I noticed that jcowan‘s most reccent entry was messing things up. I looked into the issue a bit more and found out that Planet was using version 2.7 of Mark Pilgrim’s Universal Feed Parser, which barfed quite badly on the XHTML in his Atom content.

So, I looked into it a bit more, and found out that the “nightly tarball” of Planet has not been updated since October. So much for any kind of decent release schedule.

Looking at a mailing list thread on release scheduling, I realized that the issues I was having had been fixed, and set about to check out the latest code from their version control.

Except there’s no instructions on how to do that, just a repository name. And it’s GNU Arch, which I sure as hell don’t know. So, I go to install it… apt-get install tla, on my home machine… apt tells me:

Media change: please insert the disc labeled
‘Ubuntu 5.04 _Hoary Hedgehog_ – Preview i386 Binary-1 (20050310)’
in the drive ‘/cdrom/’ and press enter

Update: Since I get a large number of hits from Google for this issue: The way to fix this is to edit your /etc/apt/sources.list, and remove the first line in it that references the cdrom drive. (You can simply put a # in front of it.) Then type apt-get update. (You’ll have to edit and update as root – type sudo before the commands to do that.) If you need more help, feel free to comment. (2006-01-10)
… right. I’m a 15 minute bike ride from home. Not going to happen. So, I switch from zeus to athena and try it, and get tla installed. Then start looking for instructions on how to check out a repository.

Apparently, the industry standard term “check out” is not part of the Arch repository system. Eventually, I wandered into Logjam’s arch repository, which provides clean instructions for how to get the code out of it:

tla register-archive http://logjam.danga.com/arch/2004
tla get logjam@danga.com–2004/logjam–dev–4.4

I was able to check out the “shiny development branch” of the Planet code, and get it in place on the site, fixing all my issues with Atom and XHTML content. All is well in the world, and Planet Swhack is a go. Never let it be said that checking out code from an arch repository is intuitive though. Anyone who thinks it is is out of their tree.

I was just looking around for a tutorial on working with MySQL in Python, and found a great Into to MySQLdb in Python page. Since I know some of you reading this are fans of Python, and may have to work with MySQL at some point, I thought this might be interesting to those of you who have to look for it.

It’s not advanced, just an intro, but quite useful, in my opinion, for what it is.