netshoot VS nixery

Now, let's use netshoot, a Docker image equipped with a set of networking troubleshooting tools that can be used for Docker networking.

nicolaka/netshoot for sure. having a preloaded array of networking troubleshooting tools in an image for kubernetes debugging is a godsend.

First off, it seems like getting tcpdump or Wireshark to capture from the container network and dumping to a file will take some extra steps. (A lot of blog posts seem to recommend this Github project - https://github.com/nicolaka/netshoot)

Some hints how to debug such problems in the future: 1. ufw drops/rejections are logged (use dmesg to view them) 2. wireshark shows all connection attempts, even those that are blocked by firewall 3. ss or netstat shows if the server is actually listening for connections 4. netshoot allows to enter docker container network namespace and do pings, curl or telnet from there

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)