05-Practice-Test-Deploy-Kubernetes-Cluster-using-Kubeadm

Practice Test - Install kubernetes cluster using kubeadm tool

If you want to build your own cluster, check these out:

• Kubeadm Clusters
• Managed Clusters

Solutions for KodeKloud lab practice test - Install Using Kubeadm

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In this practice lab, the container runtime (containerd) has already been installed. We only need to focus on the remaining node configuration, that is the kernel module and parameter settings, and installing the kubeadm cluster itself.

Note that the video preceding this lab is out of date and is still using docker container driver and an out of date Kubernetes version. The lab is up to date.

1. Install the kubeadm, kubelet and kubectl packages at exact version 1.24.0 on the controlplane and node01.

   Run the following two steps on both controlplane and node01 (use ssh node01 to get to the worker node).

   1. Configure kernel parameters

      cat <<EOF | tee /etc/modules-load.d/k8s.conf
      overlay
      br_netfilter
      EOF
      
      cat <<EOF | tee /etc/sysctl.d/k8s.conf
      net.bridge.bridge-nf-call-ip6tables = 1
      net.bridge.bridge-nf-call-iptables = 1
      net.ipv4.ip_forward = 1
      EOF
      
      sysctl --system
      

   2. Install kubernetes binaries

      Note that because you are logged into the lab as root, the use of sudo is not required.

      apt-get update
      apt-get install -y apt-transport-https ca-certificates curl
      
      mkdir -m 755 /etc/apt/keyrings
      
      curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.27/deb/Release.key | gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
      
      echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.27/deb/ /' | tee /etc/apt/sources.list.d/kubernetes.list
      
      apt-get update
      
      # To see the new version labels
      apt-cache madison kubeadm
      
      apt-get install -y kubelet=1.27.0-2.1 kubeadm=1.27.0-2.1 kubectl=1.27.0-2.1
      
      apt-mark hold kubelet kubeadm kubectl
      

2. What is the version of kubelet installed?

   kubelet version
   

   You will get an error message because the cluster isn’t installed yet, but it will tell you its version.

3. How many nodes are part of kubernetes cluster currently?

   Are you able to run kubectl get nodes? Have you run kubeadm init yet?

   No, so there are no nodes.

   0

4. Information only

5. Initialize Control Plane Node (Master Node).

   Use the following options:

   • apiserver-advertise-address - Use the IP address allocated to eth0 on the controlplane node
   • apiserver-cert-extra-sans`` - Set it to controlplane`
   • pod-network-cidr - Set to 10.244.0.0/16

   Once done, set up the default kubeconfig file and wait for node to be part of the cluster.

   1. Get the IP address of the eth0 adapter of the controlplane

      ifconfig eth0
      

      Take the value printed for inet in the output. This will be something like the following, but can be different each time you run the lab.

      10.13.26.9

   2. Run kubeadm init using the IP address determined above for --apiserver-advertise-address

      kubeadm init \
         --apiserver-cert-extra-sans=controlplane \
         --apiserver-advertise-address 10.13.26.9 \
         --pod-network-cidr=10.244.0.0/16
      

   3. Set up the default kubeconfig file

      mkdir ~/.kube
      cp /etc/kubernetes/admin.conf ~/.kube/config
      

6. Generate a kubeadm join token

   You can copy the join command output by kubeadm init which looks like

   kubeadm join 10.13.26.9:6443 --token cpwmot.ldhadf3cokvyyx60 \
     --discovery-token-ca-cert-hash sha256:ea3a622922315b14b289c6efd7b1a77cbf81d29f6ddaf03472c304b6d3228c06
   

   Note it will be different each time you do the lab.

7. Join node01 to the cluster using the join token

   1. ssh onto node01 and paste the join command from above
   2. Return to the controlplane node
   3. Run kubectl get nodes. Note that both nodes are NotReady. This is OK because we have not yet installed networking.
8. Install a Network Plugin

   1. Install flannel

      Click on “Install Netowrk Plugin” tab above the terminal. Find the link to Flannel in the page that comes up

      kubectl apply -f https://github.com/flannel-io/flannel/releases/latest/download/kube-flannel.yml
      

   2. Wait 30 seconds or so, then run kubectl get nodes. Nodes should now be ready.