Setup and Teardown a local Kubernetes Cluster with a Load Balancer, so that you can deploy to a local environment for local development.
- docker - https://docs.docker.com/get-docker/
- k3d - (v5.0.0) - https://github.com/rancher/k3d/releases
- jq - https://stedolan.github.io/jq/
- kubectls - https://kubernetes.io/docs/tasks/tools/
Create the Cluster and validate it's creation:
# create the k3d cluster
k3d cluster create local-k8s --servers 1 --agents 3 --k3s-arg "--disable=traefik@server:0" --wait
# validate the cluster master and worker nodes
kubectl get nodesDeploy the Load Balancer:
for cluster_name in $(docker network list --format "{{ .Name}}" | grep k3d); do
cidr_block=$(docker network inspect $cluster_name | jq '.[0].IPAM.Config[0].Subnet' | tr -d '"')
cidr_base_addr=${cidr_block%???}
ingress_first_addr=$(echo $cidr_base_addr | awk -F'.' '{print $1,$2,255,0}' OFS='.')
ingress_last_addr=$(echo $cidr_base_addr | awk -F'.' '{print $1,$2,255,255}' OFS='.')
ingress_range=$ingress_first_addr-$ingress_last_addr
# switch context to current cluster
kubectl config use-context $cluster_name
# deploy metallb
kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.10.2/manifests/namespace.yaml
kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.10.2/manifests/metallb.yaml
# configure metallb ingress address range
cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: ConfigMap
metadata:
namespace: metallb-system
name: config
data:
config: |
address-pools:
- name: default
protocol: layer2
addresses:
- $ingress_range
EOF
done
Create an Nginx test deployment and expose via a Load Balancer. If the Load Balancer is working correctly, an external ip address should be assigned by Metallb.
# create a deployment (i.e. nginx)
kubectl create deployment nginx --image=nginx
# expose the deployments using a LoadBalancer
kubectl expose deployment nginx --port=80 --type=LoadBalancer
# obtain the ingress external ip
external_ip=$(kubectl get svc nginx -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
# test the loadbalancer external ip
curl $external_ipExpected Output:
# expected output:
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
body {
width: 35em;
margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif;
}
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>Destroy the cluster
k3d cluster delete local-k8s
