keppel VS nixery

Even if you have your prod database on RDS, you might be able to spin up a local instance for testing. My Postgres-using applications have a script that sets up and runs a local Postgres instance for the duration of the test. It takes about 2 seconds on first run, and less than noticeable time when the DB has already been initialized.

https://github.com/sapcc/keppel/blob/master/testing/with-pos...

The ones from https://nixery.dev/

You can build your own with https://nixery.dev/

I built a service for doing this ad-hoc via image names a few years ago and it enjoys some popularity with CI & debugging use-cases: https://nixery.dev/

name is eerily similar to `nixpkgs`, i.e. the monorepo that defines all packages and one of the underlying technologies here. i get the play on buildpacks, but still, as a nix user it makes me do a double take reading the name

this is neat though, and in political terms, the elevator pitch mentions nix itself as an implementation detail in passing. hopefully, if this catches on, it'll function as a non-threatening gateway drug to nix itself, when users inevitably go digging into the weeds

for anyone interested, prior art on the nix container front: https://nixery.dev

Wow, this is excellent! At a previous job, we had been using k8s + knative to spin up containers on demand, and likewise were unhappy with the delays. Spawner seems excellent.

One question: have you had to do any custom container builds on demand, and if so, have you had to deal with large containers (e.g. a Python base image with a few larger packages installed from PyPI)? We would run up against extremely long build image times using tools like kaniko, and caching would typically have only a limited benefit.

I was experimenting using Nix to maybe solve some of these problems, but never got far enough to run a speed test, and then left the job before finishing. But it seems to me some sort of algorithm like Nixery uses (https://nixery.dev) to generate cacheable layers with completely repeatable builds and nothing extraneous would help.

Maybe that's not a problem you had to solve, but if it is, I'd love your thoughts.

Nixery – Docker images on the fly with Nix\ (38 comments)