In the previous post, we end up abusing subnets and routing to get Calico to exist on the correct subnet, but what if we could get rid of Calico’s duplicate IPAM system and just depend on our existing DHCP server to handle reservations? In this post, we’re going to prototype a cluster that uses DHCP + layer 2 Linux bridging to avoid the complications outlined in Part 3.
The official CNI documentation describes two plugins that could be relevant.
The Problem
In my previous post series, I described how I installed my Kubernetes Home Lab using Calico and MetalLB. This worked great up until I started installing smart home software that expected to be able to do local network discovery. For example, Home Assistant and my Sonos control software both attempted to do subnet local discovery using mDNS or broadcast packets. This did not work because the pods were running on a 192.168.4.0/24 subnet, but all of my physical devices were on 192.168.2.0/24.
Next up in the series, we’re going to manually configure all of the network settings to get our flat network home lab. Our flat network should not use any packet encapsulation with all pods and services fully routable to and from the existing network.
Detailed in the previous post, I want a so-called flat network because packet encapsulation tunnels IP packets inside of other IP packets and creates a separate IP network that runs on-top of my existing network.) I wanted all nodes, pods, and services to be fully routable on my home network. Additionally, I had several Sonos speakers and other smart-home devices that I wanted to be control from my k8s cluster which required pods that ran on the same subnet as my other software.
I recently setup a Kubernetes cluster home lab and wanted to do it the hard-way and share it with you. I setup a home lab so I could run my smart home software and learn more about different Kubernetes networking technologies.
This blog post is broken up into several sections. Feel free to skip directly to the section that applies to you.
When I started I had a few things already:
This project is still a work in progress, so this article serves as an introduction to the problem space and walks through how the code works.
In the past when I wrote different web applications, I used Ruby on Rails combined with the HAML template language. HAML is my favorite way to write HTML because it is an abstract representation of an HTML DOM combined with a hint of Python syntax.