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@aojea aojea released this 19 Apr 13:22
· 714 commits to dualstack since this release
dualstack
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How to create a K8s Dual Stack cluster with KIND

For the Impatient

  1. Download the KIND binary corresponding to your OS
wget https://github.com/aojea/kind/releases/download/dualstack/kind.linux
mv kind.linux kind
chmod +x kind
  1. Create your KIND configuration and store it in a file, i.e. dual-stack.yaml:
# a dual-stack cluster
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
networking:
  disableDefaultCNI: true
  ipFamily: DualStack
nodes:
- role: control-plane
- role: worker
- role: worker
  1. Create your cluster (KIND default CNI plugin does not support dual stack):
./kind create cluster --config dual-stack.yaml
  1. Install a CNI with dual stack support, :
kubectl apply -f https://raw.githubusercontent.com/aojea/kindnet/master/install-kindnet.yaml

For the Curious

  1. Create a KIND binary with dual-stack support:
# clone the fork
git clone [email protected]:aojea/kind.git
# cd into the repository
cd kind
# switch to the dualstack branch
git checkout dualstack
# and build it
go build
  1. Create your node image with dual stack support (https://kind.sigs.k8s.io/docs/user/quick-start/#building-images)
./kind build node-image --image kindest/kindnode:dualstack
  1. Create the cluster using the node-image that you just built with the following configuration:
# a dual-stack cluster
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
networking:
  ipFamily: DualStack
nodes:
- role: control-plane
- role: worker
- role: worker

./kind create cluster --image kindest/kindnode:dualstack --config config-kind.yaml -v3

Check your cluster is really working in Dual Stack

  1. Check that pods have both IPv4 and IPv6 addresses:
kubectl run -i --tty busybox --image=busybox -- ip a
kubectl run --generator=deployment/apps.v1 is DEPRECATED and will be removed in a future version. Use kubectl run --generator=run-pod/v1 or kubectl create instead.
If you don't see a command prompt, try pressing enter.
Error attaching, falling back to logs: unable to upgrade connection: container busybox not found in pod busybox-86c4cfd46-hbd44_default
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
3: eth0@eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
    link/ether 5e:20:cb:df:76:0e brd ff:ff:ff:ff:ff:ff
    inet 10.244.2.3/24 brd 10.244.2.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fd00:10:244:0:2::3/80 scope global
       valid_lft forever preferred_lft forever
    inet6 fe80::5c20:cbff:fedf:760e/64 scope link
       valid_lft forever preferred_lft forever
  1. If everything went well, you can create a deployment:

kubectl apply -f https://k8s.io/examples/application/deployment.yaml

  • We configured the cluster to use IPv4 as the default family, so we can create an IPv4 service with

kubectl expose deployment.apps/nginx-deployment

  1. We can create an IPv6 service using the following yaml
apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    run: nginx
spec:
  ipFamily: IPv6
  ports:
  - port: 80
    protocol: TCP
  selector:
    run: nginx
  1. Check services are created:
kubectl get svc
NAME               TYPE        CLUSTER-IP         EXTERNAL-IP   PORT(S)   AGE
kubernetes         ClusterIP   10.96.0.1          <none>        443/TCP   74m
nginx              ClusterIP   fd00:10:96::3cd7   <none>        80/TCP    7s
nginx-deployment   ClusterIP   10.107.244.181     <none>        80/TCP    27m
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