Waider's Geek Diary

April 10

Fri, 10 Apr 2026 23:59:59 +0100

Surprisingly, Straight Outta Compton was not completely full of gratuitous nudity, nines, AKs, and 40s. There are apparently some grumblings about details left out, portrayals, etc. but I have to say they really sold the camaraderie in NWA early on and overall I really enjoyed this. I did think their Dre was too skinny, though.

April 7

Tue, 07 Apr 2026 23:59:59 +0100

Looks like I've managed to get the Postfix thing sorted out. Not 100% clear on which specific thing / things did the trick, but possibly leaving "permit" off the smtpd_sender_restrictions completely, and adding smtpd_relay_restrictions and smtpd_sender_login_maps may be key.

April 6

Mon, 06 Apr 2026 23:59:59 +0100

Hurrah, some new version of OpenHAB has implenented an actions menu for Z-Wave devices that provides access to network tools like "Ping" and "Is Node Dead?" but alas they've prematurely gated them on "can't do this to a battery device" which, my friends, may be true if you follow the specs, but the other tool I have for this has no problem with engaging in such activities.

April 3

Fri, 03 Apr 2026 23:59:59 +0100

We'd planned on watching The Lovely Bones but it turned out to be a purchase, not a rental, so we cast about for something else and landed on Mercy which, if you strip off the AI nonsense was actually a pretty decent whodunnit. I did correctly identify the perpetrator early on, but believed their alibi and the misdirection provided; I very much correctly identified the use for the missing chemical way before the plot got to it, and I wasn't taken in by the misdirection on that. And I mostly identified the motive, although didn't catch a minor Chekov's Gun that would've given me the last bit of the puzzle.

(Checkov's Gun seems not quite the right phrase to use here, but essentially, a piece of information was provided almost in passing that was both more or less irrelevant to the story being told and highly relevant to the ending; the only reason to introduce it was so that the attentive viewer would say, "hang on a sec" at the appropriate moment.)

Anyway. Yes, the panopticon is shitty, the "courtroom" visual effects are cute but stupid, and the premise is somewhat laughable (although you never know these days), but the actual puzzle was fun.

March 27

Fri, 27 Mar 2026 23:59:59 +0000

I'm not entirely clear why I added In The Electric Mist to my watchlist, but it was a really enjoyable movie with some excellent music and some perhaps intentional, perhaps unintentional humour.

March 24

Tue, 24 Mar 2026 23:59:59 +0000

Still haven't solved the Postfix config problem. It's nice that I've got debugging and a script to exercise the desired pass/fail scenarios, but it's frustrating that everthing I try to enable one condition breaks the other, and vice versa.

March 21

Sat, 21 Mar 2026 23:59:59 +0000

Well, on the upside, I now know how to do debug logging for a specific sender IP in Postfix. Alas, I have not managed to debug my specific problem: I want allmail@example.com to wind up in the waider mailbox, but I do not want to receive spam where someone purports to be someluser@example.com and thereby bypasses the various hurdles I am attempting to put in the way of this. It seems that as soon as you say "virtual domain goes to mailbox", even sender addresses are rewritten to check against the allowlist which is exactly what I don't want and also seems to contradict what the documentation says.

To be abundantly clear: I'm trying to block envelope-level spoofing. It appears that it will happily iterate over the rules I've provided, and at some point stumble on "oh, someluser@example.com is an example.com address and so maps to waider and is thereby permitted. Yay!" and I toss virtual config out the window again. This says nothing about virtual, canonical, rewrite, or aliases; this suggests that the rewriting only happens after the mail is queued, but the testing I'm doing doesn't even get to the point of submitting the mail, just the envelope headers, and I can see that's returning me a 250 response and the logs show it's done a virtual lookup in order to arrive at this conclusion. In fact I'm looking that page again right now and it says, "Virtual aliasing is applied only to recipient envelope addresses, [...]." (my underlining). Right there in black and white. LIES.

Maybe I'll figure it out tomorrow. Note, this is broken on a live server I own; I'm trying to fix it on the new server I'm setting up so I can never again see a faked-sender-envelope spam.

March 20

Fri, 20 Mar 2026 23:59:59 +0000

Dead of Winter, in which Emma Thomson does a sort of badass Frances McDormand. It's a good movie, with approximately the same sort of pacing as the speech in that part of the world - slow, but relentless. I was calling the shots a bit in places - there are a lot of Chekov's Guns in this movie - but that didn't detract from it.

March 18

Wed, 18 Mar 2026 23:59:59 +0000

Dammit, another one of my scrapers just had the format changed from out under it. Five minutes of hackery verifes that the replacement is parseable, but will need more work than e.g. a trivial renaming of CSS selectors.

March 16

Mon, 16 Mar 2026 23:59:59 +0000

Voyager, in which Star Trek does Stephen King's Christine. Kinda silly.

New mail server is up and configured with DKIM, DMARC and SPF outbound. No idea what's currently enabled inbound beyond Can't Spoof Me. Will find out shortly how regrettable that is, I imagine. I will say it's nice having a more-or-less throwaway domain to test this stuff out on, since if I screw it up it's no big deal.

March 15

Sun, 15 Mar 2026 23:59:59 +0000

Tesco delivery notice format change again. As before it's moving towards cleaner HTML but it doesn't make it any less annoying to have to figure out what they've done and update my scripting accordingly. I do try to make this stuff deal with variations in input, but there's a point at which you have to embrace the crazy and pin down an exact class attribute, or an arbitrary hierarchy, and those are the things that break.

March 14

Sat, 14 Mar 2026 23:59:59 +0000

Beverly Hills Cop? don't mind if I do. It's aged a bit (or I have, or both), but it's still a pretty decent movie.

March 13

Fri, 13 Mar 2026 23:59:59 +0000

Misconduct kept us guessing right to the end who was pulling the strings - and why - but the last scene was, I think, an unnecessary gotcha added to the back of the story. Also the lead character had a worse sense of decision-making than Twilight girl.

March 12

Thu, 12 Mar 2026 23:59:59 +0000

Discovering which bits of my server setup are so stale they no longer have equivalents on new installations. Dammit. Also very cautiously setting up an email server. Which, well, hurdles. Hoops. Flaming barrels.