Kubernetes

This repository contains scripts and instructions to provision local Kubernetes environments.

Kind

Kind allows provisioning multi-node clusters on Docker containers. The advantage of using Kind is that it closely represents production-like environments and it provisions incredibly fast.

Prerequisites

• Kind
• Docker

Step-by-step

1. The Kind cluster runs on a custom Docker network: kind. We require the Kind CIDR in order to allocate a narrow range of IPs to Metallb. Metallb is a layer 7 load balancing solution for bare-metal Kubernetes clusters. Inspect the Kind network to determine the CIDR range.

$ docker network inspect -f '{{range .IPAM.Config}}{{.Subnet}}{{"\n"}}{{end}}' kind | head -n1
172.18.0.0/16

2. From the CIDR range we pick a sensible IP-range for Metallb to use (172.18.255.200-172.18.255.250). These IPs will be dynamically allocated to Kubernetes LoadBalancer services. Update setup/metallb.cm.yaml according to the chosen IP range.

apiVersion: v1
kind: ConfigMap
metadata:
  namespace: metallb-system
  name: config
data:
  config: |
    address-pools:
    - name: default
      protocol: layer2
      addresses:
      - 172.18.255.200-172.18.255.250

3. Spinning up the Kind cluster is as simple as running the Makefile.

$ make cluster
kind create cluster --config=setup/config.yaml
Creating cluster "kind" ...
 ✓ Ensuring node image (kindest/node:v1.21.1) 🖼
 ✓ Preparing nodes 📦 📦 📦  
 ✓ Writing configuration 📜 
 ✓ Starting control-plane 🕹️ 
 ✓ Installing CNI 🔌 
 ✓ Installing StorageClass 💾 
 ✓ Joining worker nodes 🚜 

4. Inspect worker node availability.

$ kubectl get no
NAME                 STATUS   ROLES                  AGE     VERSION
kind-control-plane   Ready    control-plane,master   2m21s   v1.21.1
kind-worker          Ready    <none>                 105s    v1.21.1
kind-worker2         Ready    <none>                 105s    v1.21.1

5. Clean the Kind cluster.

$ make clean
kind delete cluster
Deleting cluster "kind" ...