k8s.github.io

Demo - Deployment with Kubeadm tool

Apple Silicon

If you have an Apple M1 or M2 (Apple Silicon) machine, then please follow the separate instructions here.

For all other operating systems/hardware including Intel Apple, please remain on this page…

VirtualBox/Vagrant

In this lab, you will build your own 3-node Kubernetes cluster using kubeadm with VirtualBox and Vagrant

Important Note

This lab cannot currently be performed on Apple M1/M2. We are waiting for VirtualBox to release a version that is fully compatible with Apple Silicon.

Changes to Lecture

Since the video was recorded, Kubernetes and Ubuntu have progressed somewhat.

We are now using the latest stable release of Ubuntu - 22.04

Docker is no longer supported as a container driver. Instead we will install the containerd driver and associated tooling.

Lab Instructions

  1. Install required software

    * VirtualBox: https://www.virtualbox.org/ * Vagrant: https://developer.hashicorp.com/vagrant/downloads

  2. Clone this repository

    ``` git clone https://github.com/kodekloudhub/certified-kubernetes-administrator-course.git cd certified-kubernetes-administrator-course ```

  3. Bring up the virtual machines

    ``` vagrant up ``` This will start 3 virtual machines named * `kubemaster` - where we will install the control plane * `kubenode01` * `kubenode02`

  4. Check you can SSH to each VM

    Note: To exit from VM's ssh session, enter `exit` ``` vagrant ssh kubemaster ``` ``` vagrant ssh kubenode01 ``` ``` vagrant ssh kubenode02 ```

  5. Initialize the nodes.

    The following steps must be performed on each of the three nodes, so ssh to kubemaster and run the steps, then to kubenode01, then to kubenode02

    1. Configure kernel parameters

         {
   cat <<EOF | sudo tee /etc/modules-load.d/11-k8s.conf
   br_netfilter
   EOF

   sudo modprobe br_netfilter

   cat <<EOF | sudo tee /etc/sysctl.d/11-k8s.conf
   net.bridge.bridge-nf-call-ip6tables = 1
   net.bridge.bridge-nf-call-iptables = 1
   net.ipv4.ip_forward = 1
   EOF

   sudo sysctl --system
   }

    2. Install containerd container driver and associated tooling

      ```bash { sudo apt update sudo apt install -y apt-transport-https ca-certificates curl sudo curl -fsSLo /usr/share/keyrings/kubernetes-archive-keyring.gpg https://packages.cloud.google.com/apt/doc/apt-key.gpg echo "deb [signed-by=/usr/share/keyrings/kubernetes-archive-keyring.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list sudo apt-get install -y containerd #sudo mkdir -p /opt/cni/bin #wget -q --https-only \ # https://github.com/containernetworking/plugins/releases/download/v0.8.#6/cni-plugins-linux-amd64-v0.8.6.tgz \ # https://github.com/kubernetes-sigs/cri-tools/releases/download/v1.25.0/#crictl-v1.25.0-linux-amd64.tar.gz #sudo tar -xzf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin #sudo tar -xzf crictl-v1.25.0-linux-amd64.tar.gz -C /usr/local/bin } ```

    3. Install Kubernetes software

      This will install the latest version ```bash { sudo curl -fsSLo /usr/share/keyrings/kubernetes-archive-keyring.gpg https://packages.cloud.google.com/apt/doc/apt-key.gpg echo "deb [signed-by=/usr/share/keyrings/kubernetes-archive-keyring.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources. sudo apt update sudo apt-get install -y kubelet kubeadm kubectl sudo apt-mark hold kubelet kubeadm kubectl # Configure crictl so it doesn't print ugly warning messages sudo crictl config \ --set runtime-endpoint=unix:///run/containerd/containerd.sock \ --set image-endpoint=unix:///run/containerd/containerd.sock } ```

  6. Initialize controlplane node

    1. Get the IP address of the `eth0` adapter of the controlplane ``` ip addr show dev enp0s8 ``` Take the value printed for `inet` in the output. This should be: > 192.168.56.11 1. Create a config file for `kubeadm` to get settings from ```yaml kind: ClusterConfiguration apiVersion: kubeadm.k8s.io/v1beta3 kubernetesVersion: v1.25.4 # <- At time of writing. Change as appropriate controlPlaneEndpoint: 192.168.56.11:6443 networking: serviceSubnet: "10.96.0.0/16" podSubnet: "10.244.0.0/16" dnsDomain: "cluster.local" controllerManager: extraArgs: "node-cidr-mask-size": "24" apiServer: extraArgs: authorization-mode: "Node,RBAC" certSANs: - "192.168.56.11" - "kubemaster" - "kubernetes" --- kind: KubeletConfiguration apiVersion: kubelet.config.k8s.io/v1beta1 cgroupDriver: systemd serverTLSBootstrap: true ``` 1. Run `kubeadm init` using the IP address determined above for `--apiserver-advertise-address` ``` sudo kubeadm init \ --apiserver-cert-extra-sans=kubemaster01 \ --apiserver-advertise-address 192.168.56.11 \ --pod-network-cidr=10.244.0.0/16 ``` Note the `kubeadm join` command output at the end of this run. You will require it for the step `Initialize the worker nodes` below 1. Set up the default kubeconfig file ``` { mkdir ~/.kube sudo cp /etc/kubernetes/admin.conf ~/.kube/config sudo chown vagrant:vagrant ~/.kube/config } ```

  7. Initialize the worker nodes

    The following steps must be performed on both worker nodes, so `ssh` to `kubenode01` and run the steps, then to `kubenode02` * Paste the `kubeadm join` command from above step to the command prompt and enter it.