k3d

k3d is a lightweight wrapper to run k3s (Rancher Lab’s minimal Kubernetes distribution) in docker.

→ k3d.io, docs, code

Installation

• Download & install latest release (ref. k3d.io)

# runs installation script
wget -q -O - https://raw.githubusercontent.com/k3d-io/k3d/main/install.sh | bash

Basic commands

Command	Action
k3d cluster create <mycluster>	Create a cluster
k3d cluster list	List the clusters
k3d cluster stop <mycluster>	Stops a cluster
k3d cluster start <mycluster>	Starts a cluster
k3d cluster delete <mycluster>	Delete a cluster

Getting started

• Create a cluster

# creates a cluster
k3d cluster create mycluster -p "8081:80@loadbalancer" -p "8082:443@loadbalancer" --agents 2

# displays cluster information (kubectl configuration is automatically updated and set to use the new cluster context)
kubectl cluster-info

# ensures coredns and traefik (ingress controller) are deployed by default (k3s behavior)
kubectl get deploy -n kube-system

# (optional) writes and uses specific kubectl configuration
export KUBECONFIG="$(k3d kubeconfig write mycluster)"

• Deploy a basic workflow (ref. k3d Guides > Exposing Services)

# creates a nginx (web server) deployment
kubectl create deployment nginx --image=nginx

# exposes the deployment with a service
kubectl create service clusterip nginx --tcp=80:80

# provides an ingress to the service
cat <<EOF | kubectl apply -f -
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: nginx
  annotations:
    ingress.kubernetes.io/ssl-redirect: "false"
spec:
  rules:
    - host: nginx.dev.local
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: nginx
                port:
                  number: 80
EOF

# checks everything is ok
kubectl get svc,pod,deploy,ingress

# makes sure the website can be reached
curl localhost:8081/

• Update hosts file

127.0.0.1  nginx.dev.local

• Make sure ingress is working

curl nginx.dev.local:8081/

• Clean-up

# deletes the cluster
k3d cluster delete mycluster

Advanced usage

• Kubernetes - K3D with Load Balancer

• CoreDNS configuration

# displays coredns configmap
kubectl -n kube-system get configmap coredns -o yaml