s6-overlay VS k3s

FROM docker.io/grafana/grafana-oss:9.5.12-ubuntu # Set USER to root escalating priviliges to perform installation of litestream and s6-overlay USER root RUN apt-get -qq update && \ apt-get -qq install -y xz-utils \ && rm -rf /var/libs/apt/lists/* # https://github.com/benbjohnson/litestream-s6-example/blob/main/Dockerfile # Download the static build of Litestream directly into the path & make it executable. ADD https://github.com/benbjohnson/litestream/releases/download/v0.3.11/litestream-v0.3.11-linux-amd64.tar.gz /tmp/litestream.tar.gz RUN tar -C / -xvzf /tmp/litestream.tar.gz ARG S6_OVERLAY_VERSION="3.1.5.0" # Download the s6-overlay for process supervision. ADD https://github.com/just-containers/s6-overlay/releases/download/v${S6_OVERLAY_VERSION}/s6-overlay-noarch.tar.xz /tmp RUN tar -C / -Jxpf /tmp/s6-overlay-noarch.tar.xz ADD https://github.com/just-containers/s6-overlay/releases/download/v${S6_OVERLAY_VERSION}/s6-overlay-x86_64.tar.xz /tmp RUN tar -C / -Jxpf /tmp/s6-overlay-x86_64.tar.xz # Copy s6 init & service definitions. COPY etc/s6-overlay /etc/s6-overlay # Copy Litestream configuration file. COPY etc/litestream.yml /etc/litestream.yml # The kill grace time is set to zero because our app handles shutdown through SIGTERM. ENV S6_KILL_GRACETIME=0 # Sync disks is enabled so that data is properly flushed. ENV S6_SYNC_DISKS=1 # Reset USER to 472 to reset the escalated privileges USER 472 # # Run the s6 init process on entry. ENTRYPOINT [ "/init" ]

Learn S6-Overlay that allows to have one docker container for multiple processes... make immich docker compose not a two page 8 containers long? But just one clean container with healthcheck. Convince the devs to switch to it.

Custom base docker image with S6 overlay (for more details : just-containers/s6-overlay)

https://github.com/just-containers/s6-overlay can do what you need.

Used s6-overlay[1] to start a lot daemons in a docker-image for demo purposes - postgres, tomcat, mysql, php-fpm, apache (don't ask why ;) - s6 worked really well and was reliable and stable - I enjoyed it very much. It was also possible to reliable pass SIGTERM to the daemons in the image for clean shutdown and it was easily possible to configure logging to stdout with a prefix. Modelling dependencies (waiting on database before starting app etc.pp) is possible via shell-scripts. It's super flexible but out of the box it's more like a collection of powerful tools not a complete package - but that's good. It's in the tradition of djb daemontools and is very unix - as in doesn't talk a lot and you better know how each part works but - and that's really cool - it's modular and simple and once you get a grip on it you can easily reason about it. systemd takes a completely different approach and also solves a kind of differnt problem - this is like small pieces of lego that compose well instead of one big chunk of glib/dbus/glibc only c-code.

1: https://github.com/just-containers/s6-overlay

Every container has some entrypoint, whether it launches a single binary, runs a "process supervisor" like s6, or does some pre-setup before running a service, like a database.

If you *really* want to make your own containers with PUID/PGID support checkout "S6-overlay" and the linuxserver "baseimage". Somewhere in the startup they end up running:

FROM ubuntu:20.04 ARG S6_OVERLAY_VERSION=3.1.0.1 ARG DEBIAN_FRONTEND=noninteractive ENV TZ="America/New_York" RUN apt-get update && apt-get install -y xz-utils ADD https://github.com/just-containers/s6-overlay/releases/download/v${S6_OVERLAY_VERSION}/s6-overlay-noarch.tar.xz /tmp RUN tar -C / -Jxpf /tmp/s6-overlay-noarch.tar.xz ADD https://github.com/just-containers/s6-overlay/releases/download/v${S6_OVERLAY_VERSION}/s6-overlay-x86_64.tar.xz /tmp RUN tar -C / -Jxpf /tmp/s6-overlay-x86_64.tar.xz RUN apt-get autoclean && rm -rf /tmp/* ENTRYPOINT ["/init"]

Not sure about unbound or what have inside the pihole base image, you may try to run the service in foreground or use some tiny init service for that container (I just learnt that s6 may work for that, but you must be aware how it should be used)

Opinionated meaning it picks, install, patches your CNI/Ingress/Load Balancer/DNS Server/Metrics Server/Monitoring Setup.

k3s is probably most well known as it ships with bunch of preinstall software: https://github.com/k3s-io/k3s so you can just start throwing yaml files at cluster and handling workloads. It's what I use for my homelab.

Paid things I've heard of include OpenStack and SideroLabs. Haven't used personally by SRE coworkers say good things about them.

For self-hosting I've found https://k3s.io to be really good from the SUSE people. Works on basically any Linux distro and makes self-hosting k8s not miserable.

Yes it’s going to depend on which k8s distribution you’re using. We have work in-progress for k3s to natively support nix-snapshotter: https://github.com/k3s-io/k3s/pull/9319

For other distributions, nix-snapshotter works with official containerd releases so it’s just a matter of toml configuration and a systemd unit for nix-snapshotter.

We run Kubernetes outside of NixOS, but yes the NixOS modules provided by the nix-snapshotter certainly make it simple.

K3S: is a lightweight distribution of Kubernetes that is designed for resource-constrained environments. It is an excellent option for running Kubernetes on a virtual machine or cloud server.

I recently purchased a used Lenovo M900 Think Centre (i7 with 32GB RAM) from eBay to expand my mini-homelab, which was just a single Synology DS218+ plugged into my ISP's router (yuck!). Since I've been spending a big chunk of time at work playing around with Kubernetes, I figured that I'd put my skills to the test and run a k3s node on the new server. While I was familiar with k3s before starting this project, I'd never actually run it before, opting for tools like kind (and minikube before that) to run small test clusters for my local development work.

Kubernetes - k3s distribution

I’ve created a local cluster with K3S and installing Windmill could not be simpler with just one chart to configure, which already has sane defaults to get started. For this demo we will also configure workers to passthrough environment variables to our scripts so that they have access to the Kubernetes API server for later.

You should be familiar with Kubernetes and have set up a Kubernetes cluster. I recommend k3s.