How to install IPv4/IPv6 Kubernetes Dual Stack Cluster ?

 

   Steps to install Kubernetes Dual Stack Cluster 

Below lists simple steps that can be followed to set up a dual stack cluster using ubuntu VMs. You can set it up in any OS. I have windows machine.

1 master+ 2 node deployment

 Prerequisites

• Oracle VM Virtual Box : Download from https://www.virtualbox.org/
• Turn on hardware virtualization support in BIOS Settings. (Hyper V in windows 10 )

Create VMs

Create 2 VMs for 1 master with 1 worker node cluster with below requirements

• Version: Ubuntu (64-bit)
• Processor: 2 CPU
• 4 GB RAM
• Network : Select NAT as adapter 1 and Host only adapter as adapter 2

Initial setup on all nodes

1. Turn off swap  using  sudo swapoff -a
            Comment the line with swap in /etc/fstab
             nano /etc/fstab  
2. Add IPv6 address on all nodes
           E.g.  master# ifconfig enp0s8 inet6 add 2021::100/64 up
3. Add IP address (including IPv4 and IPv6 address) of all nodes in etc/hosts with details of ip address and hostname.                     

      4.   Run below command on all nodes

    sudo sysctl -w net.ipv6.conf.all.forwarding=1

      5. Install docker

            apt-get update && apt-get install -y docker.io

      6. Install Kubelet, Kubeadm adn Kubectl

          apt-get update && apt-get install -y apt-transport-https curl

          curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -

          cat << EOF >/etc/apt/sources.list.d/kubernetes.list

             deb http://apt.kubernetes.io/ kubernetes-xenial main

           EOF

          apt-get update && apt-get install -y kubelet kubeadm kubectl

    7. Update cgroup-driver in all nodes

            nano /etc/systemd/system/kubelet.service.d/10-kubeadm.conf

 

          Edit kubeadm.conf file and add below variable after the last Environment

           Environment="cgroup-driver=systemd/cgroup-driver=cgroupfs" 

       #Also add below configuration in all worker nodes to connect pods from master

        Environment="KUBELET_EXTRA_ARGS=--node-ip=<worker IP address>"

   8. Create kubeadmin-config.yaml

    #Example config file

        apiVersion: kubeadm.k8s.io/v1beta2

        featureGates:

          IPv6DualStack: true

        kind: ClusterConfiguration

        apiServer:

          extraArgs:

            advertise-address: <API Address>

        networking:

          dnsDomain: cluster.local

          podSubnet: "<IPV4 range>/16, <IPV6 range>/48"

          serviceSubnet: "<IPV4 range>/16,<IPV4 range>/112"  

        ----

        apiVersion: kubeadm.k8s.io/v1beta2

        kind: InitConfiguration

        localAPIEndpoint:

          advertiseAddress: <API Address>

          bindPort: 6443

        ---

     9.  Install K8s using created config file

            kubeadm init --config /home/kubeadm-config.yaml

   10. Install Calico

     wget https://docs.projectcalico.org/v3.17/manifests/calico.yaml

       Edit configuration and enable dual stack as explained under section 'Enable dualstack' in

           https://docs.projectcalico.org/networking/ipv6

        Kubectl apply -f calico.yaml

    11. Deploy and check your application Pods and see if they have received both IP addresses   :)