I’d been looking for a way to renew my Let’s Encrypt TLS/SSL certificates via AWS Lambda (using DNS authentication by updating Route 53) rather than web authentication. This project started since I wanted to separate out my mail server from my web server, and while I suppose I could run Apache (or whatever) on the mail server just to be able to request certificates it seems kind of silly, and this sort of automatic run-a-piece-of-code-occasionally scenario seemed like the perfect chance to use AWS Lambda.

I expected this to be a common & solved problem, but in my searching around the Internet I didn’t really see exactly what I was looking for. There were some solutions out there, but they seemed overly complicated for just “renew my certificates every two months”, and some were out of date (not even updated to the ACME v2 protocol). So I figured I’d need to write at least some code myself.

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Are you sure?


I wish that when computers ask “Are you sure?” that there were a response available for “No, I’m not sure, but I’d like you to proceed anyway. But thanks for asking!”

Tip of the Day: Dust is bad for computers

When your computer’s fan seems to be louder and come on more often than usual, it probably means it’s a good idea to open it up and blow the dust out.

Our main living room HTPC, an Intel NUC6i7KYK, was seeming really loud, even when not under load. Looking back, it was clearly one of those things where it must have been getting steadily worse over time, but so gradually that I hadn’t actually noticed just how much louder it was and how much more often the fan was at high speeds than when we first got it. Opening it up and blowing the dust out (and it really didn’t seem like that much dust at the time) substantially improved things.

The CPU was running around 70°C even with no load, and pushing 80°C with the fan on full speed when under load. After blowing out the dust, it’s now around 50°C or even less, and even under load I haven’t seen it over 60°C and the fan is still quiet enough to not really be noticeable. It’s just such a small computer that even just a bit of dust can make a big impact. I clearly should have been monitoring it more carefully, I just hadn’t even thought to do so until it had gotten so bad that we noticed a problem and I started taking measurements.

Recurse as needed


Staples “Brighton Professional” brand hand soap has, like most commercial products that have any sort of chemicals in them, a Material Safety Data Sheet stating important stuff like a list of the chemicals in it, so that it’s documented what chemicals are in the workplace. It also includes First Aid information, just because one wants every product to have clear instructions about what to do if swallowed or whatnot.

One of the First Aid instructions is “In case of skin contact”. So, just in case this hand soap for some reason ends up touching your skin, here’s what you should do:

“In case of skin contact : Wash with water and soap as a precaution”

Quote of the Day


I am starting to think that the right way to think about blockchain and cryptocurrencies and tokens might be the way you’d think about stocks, if stocks had just been invented. Here in 2017, it is uncontroversial to say that the invention of limited-liability joint stock companies utterly changed how humans organized their economic activities, and had huge impacts on economic productivity and on society as a whole. But it is also fair to say that the first few hundred years of stocks were mostly fraud and irrational speculation. Similarly with cryptocurrencies and initial coin offerings, it is possible both that proponents’ grandiose claims about how they will transform finance and society will turn out to be true, and that most crypto stuff in our lifetimes will be nonsense.

— Matt Levine, “Money Stuff”, July 11, 2017

GUID as a Service

I’m pleased to announce the creation of GUID as a Service, bringing creation of Globally Unique Identifiers into the “cloud” era. This has been a fun hobby project to learn about AWS API Gateway and Lambda, and so I figured I’d make a little thing and share it with the world, just because I can.