K3D Load Balancing — MetalLB on Mac

8 minute read Published

How to workaround the Docker host network limitation on macOS using Kubernetes in Docker with K3s and MetalLB.

In this post I’m going to show you a neat little hack to get a bare metal load balancer called MetalLB working in K3s under Docker Desktop for Mac. Before you get started please follow the steps to set-up K3s using k3d with Rancher if this is your first time using Kubernetes. If you already have a K3D cluster running, we’ll be creating a new one for experimentation.

This hack allows Mac users running Kubernetes locally via Docker have it provide EXTERNAL-IP addresses from a pool of addresses so multiple K8s services can be run on the same port, namely 80 (http) and 443 (https), at the same time. Effectively this is a workaround for docker/for-mac/issues/155. Without this hack LoadBalancer IP addresses will show as <pending> or <none> in kubectl.

Let’s see how it works.