Hiding the port number on SchoolBell using mod_rewrite
I've just set up the Shuttleworth Foundation's slick little calendar server, SchoolBell. It runs on port 7180 by default, but I didn't want to my colleagues (that's what you call everyone else if you work at a school) to have to remember that. Digging around in the README file for a related program, SchoolTool, I found a suggestion that mod_rewrite would help me out.
In the end, this worked on Ubuntu 5.10, Breezy Badger:
(lang=apache)
ServerName calendar.chewonki.org
RewriteEngine On
RewriteRule ^/(.*) http://calendar.chewonki.org:7180
Note that I'm mapping most of our hosts (like "calendar") using our internal DNS server, so all you wandering internet folks can't resolve the URLs above. I also had to enable the mod_rewrite module with the a2enmod command.
We'll see how SchoolBell works. I suspect we'll have 15 excited users, 10 people who think it's a pain in the ass to use computers for calendaring, and everyone else (from the set of all colleagues) won't even know it exists.
Update: I just upgraded Breezy to use SchoolBell 1.2.2 from 1.2.1. The performance difference is shocking. From my little bit of experimenting, it's 5-10 times faster. The slowest task was viewing a whole year at once. It previously took 15-20 seconds to load; now it's 2-3 seconds, and the server is still configuring packages to complete the update, and the server sucks. Well done and thank you, Tom Hoffman, Mark Shuttleworth, and co.
Hybrid vs. Gas-only pricing: Joe White gets it wrong.
The inestimable Ben Harris just alerted me to a little interview with Joe White, the Wall Street Journal's man in Detroit, about the costs of hybrid cars. The ~4 minute interview is available in Realplayer and Windows Media formats.
Maybe I'm crazy, but I think Joe White may have made a mathematical error. He says that he would save $746 in gas per year if he bought a Prius instead of a comparable gas-only car. He also says that the hybrid technology raises the cost of a car by $7000-$8000 by comparing the Prius to a Honda Civic. The Prius is selling for around $21K right now, and only the extreme low-end Civics sell for $7000-$8000 less than that, so it's not a great comparison, but even using his numbers, don't you win with a hybrid in year 11? I'm thinking that $746 per year * 10 years = $7460. That's assuming that you don't get any tax breaks and the price of gas stays constant in the next 10 years. I am ignoring the interest you'd get on your $7000-$8000 in the bank for 10 years-- at 3% interest compounded annually, that's about $2500, but Joe White claims he was ignoring that too. (That's still a simplification, as it assumes that you're paying cash for either car, which people rarely do.)
As a realistic assessment, you break even after maybe 13 years if you buy a hybrid Prius in the US in 2005, assuming you get a $2000 tax deduction, have a tax rate of 30%, would have invested your savings at 3% for those 13 years, and the price of gas doesn't rise. Plus, you get to drive a car that looks like a spaceship and can drive silently at low speeds.
The interviewer, Steve Inskeep, does a reasonable job of pressing Joe White. Inskeep asks something like "Aren't there other reasons that people buy hybrids, though?" White's reply is that buying a hybrid car is "making a statement" that you value, "supporting the development of new kind of technology."
From my perspective, buying a hybrid is putting value on keeping our planet livable for the future. To me, it's a moral judgment-- I think I shouldn't ruin resources that we hold in common, e. g. our atmosphere, just because it's cheaper for me today. If we rule out moral considerations, White's still wrong. A $13,000 Honda Civic might be cheap, but a stolen Honda Civic is free!
Anyway, enough of this-- I have to get back to my regular Friday morning routine of watching street performers in Harvard Square, but ducking out before they pass the hat. Then I'm going to shoplift 4 packs of Reese's Peanut Butter Cups from the Brooks Pharmacy on Mass Ave, eat all 7 cups, and throw the wrappers in the street. Ah, what a life!
Am I in over my head?
Here is a conversation I had today, shortened for humorous effect:
"Are we using the new server yet?"
"We don't know."
"Well, I was thinking about installing some network monitoring software on it, you know, maybe make a map of the network."
"Oh, we have that. We have an inventory. It's part of our technology plan."
"Great! Is the technology plan on the server somewhere?"
"I don't know. . . . I have a paper copy."
