k3s VS Portainer

K3s is another compact Kubernetes distribution. Developed by SUSE, it's packaged as a single binary that comes in at less than 70MB. Despite this tiny footprint, K3s is certified as compatible with upstream Kubernetes, is ready for production use, and supports high availability.

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.

Portainer is a container management platform that provides a powerful web interface to administer your workloads. It natively supports Kubernetes environments to help you manage your Pods, Deployments, Helm charts, and other cluster resources. Portainer also provides robust RBAC capabilities and an external authentication layer, letting you grant team members access to Kubernetes through Portainer without directly exposing your cluster.

This episode is actually why I started this series in the first place. I am an active Docker user and Docker fan, but I like containers and DevOps topics in general. I am a moderator on the official Docker forums and I see that people often struggle with the installation process of Docker CE or Docker Desktop. Docker Desktop starts a virtual machine, and the GUI is to manage the Docker CE inside the virtual machine even on Linux. Even though I prefer not to use a GUI for creating containers, I admit it can be useful in some situations, but you always need to be ready to use the command line where all the commands are available. In this episode I will use Ansible to install Docker CE in the previously created virtual machine, and I will also install a web-based graphical interface, Portainer.

Portainer

> Any tips on the minimum hardware or VPS's needed to get a small swarm cluster setup?

From my testing, Docker Swarm is very lightweight, uses less memory than both Hashicorp Nomad and lightweight Kubernetes distros (like K3s). Most of the resource requirements will depend on what containers you actually want to run on the nodes.

You might build a cluster from a bunch of Raspberry Pis, some old OptiPlex boxes or laptops, or whatever you have laying around and it's mostly going to be okay. On a practical level, anything with 1-2 CPU cores and 4 GB of RAM will be okay for running any actually useful software, like a web server/reverse proxy, some databases (PostgreSQL/MySQL/MariaDB), as well as either something for a back end or some pre-packaged software, like Nextcloud.

So, even 5$/month VPSes are more than suitable, even from some of the more cheap hosts like Hetzner or Contabo (though the latter has a bad rep for limited/no support).

That said, you might also want to look at something like Portainer for a nice web based UI, for administering the cluster more easily, it really helps with discoverability and also gives you redeploy web hooks, to make CI easier: https://www.portainer.io/ (works for both Docker Swarm as well as Kubernetes, except the Kubernetes ingress control was a little bit clunky with Traefik instead of Nginx)

In this section, we will add Portainer to help us in managing our Docker containers. You can find more details about it here. To integrate Portainer into our EC2 project, we can follow these steps:

Git issues pointing to: https://docs.portainer.io/v/ce-2.9/start/install/agent/swarm/linux gives a ERR_TOO_MANY_REDIRECTS.

I am currently running Portainer, but webhooks (GitOps) appear to be broken ( [2.19.0] GitOps Updates not automatically polling from git · Issue #10309 · portainer/portainer · GitHub ) and so I cannot send webhook to redeploy a stack. So, looking for alternatives. Using this as a good excuse to learn more about docker and CI/CD etc.

A Synology NAS running Portainer (https://www.portainer.io/) running Paperless NGX (https://github.com/paperless-ngx/paperless-ngx)

This works better than I can possibly tell you.

I have an Epson WorkForce ES-580W that I bought when my mother passed away to bulk scan documents and it scans everything, double-sided if required, multi-page PDFs if required, at very high speed and uploads everything to OneDrive, at which point I drag and drop everything into Paperless.

I could, thinking about it, have the scanner email stuff to Paperless. Might investigate that today.

Paperless will OCR it and make it all searchable. This setup is amazing, I love living in the future.

> I've come to the conclusion (after trying kops, kubespray, kubeadm, kubeone, GKE, EKS) that if you're looking for < 100 node cluster, docker swarm should suffice. Easier to setup, maintain and upgrade.

Personally, I'd also consider throwing Portainer in there, which gives you both a nice way to interact with the cluster, as well as things like webhooks: https://www.portainer.io/

With something like Apache, Nginx, Caddy or something else acting as your "ingress" (taking care of TLS, reverse proxy, headers, rate limits, sometimes mTLS etc.) it's a surprisingly simple setup, at least for simple architectures.