Here are some of the things I learned this week, in the order I’ve noted them down. Starting this week, each item will have its own headline to keep things tidy and easily linkable.

# Prima facie

• A Latin expression that means on the first impression or on the face of it (wiki, via this article on Daring Fireball).

# Docker, Nginx, and Let’s Encrypt

• This weekend I wrote a tiny Express.js app to use as a POSSE server for this website. After learning the hard way about the difference between CMD and RUN in a Dockerfile, I ran into an issue with my nginx-proxy and Let’s Encrypt setup on the VPS. After several hours of poking around, I found an outdated version of this Docker image to be the culprit, which will make me think twice before version-locking security dependencies like this one.

# The Walrus Operator

• The assignment operator := in Python is called the walrus operator (via this episode of the Lex Fridman podcast). Simply brilliant; I mean, look at it!