Kubernetes Cluster using Multipass

You can use Multipass to create Ubuntu VMs and then set up a Kubernetes cluster. This is useful for studying purposes for example, CKA-CKAD-CKS certifications.

Instructions

These are the links to install and create kubernetes cluster:

1. Install Container runtimes
2. Install kubeadm
3. Create a cluster with kubeadm

Step 1. Multipass

Multipass is a tool to launch and manage VMs with a single command. It’s designed for developers who want a fresh Ubuntu environment with a single command and works on Linux, Windows and macOS.

On Linux it’s available as a snap:

sudo snap install multipass --beta --classic`

See install Multipass for more details.

Step 2. Clone repository

git clone https://github.com/willianccs/multipass-k8s-labs.git
cd multipass-k8s-labs/

Step 3. Create two Ubuntu VMs on you host

./1-multipass-start.sh

Step 4. Creating a cluster

You can override the agents versions with the environment variable: K8S_VERSION

Default: 1.24.6-00

4.1 Setup control-plane node

# default version
multipass exec control-plane -- /tmp/2-install.sh
---
# specific version
multipass exec control-plane -- sh -c 'K8S_VERSION=1.25.2-00 /tmp/2-install.sh'

4.1.2 Copy join command

Copy the output like this, and prepare to run it in Step 4.2.1

kubeadm join 192.168.64.3:6443 --token al0kvi.x60mi1xj4zesqnq3     --discovery-token-ca-cert-hash sha256:f4ff0c7684bbac599a8208b94bb28e451023662ab51bc1ce16f60a855a85e2a5

4.2 Setup worker nodes

# default version
multipass exec worker-01 -- /tmp/2-install.sh
---
# specific version
multipass exec worker-01 -- sh -c 'K8S_VERSION=1.25.2-00 /tmp/2-install.sh'

4.2.1 Joining nodes

Then run what you copied from Step 4.1.2, something like this...

multipass exec worker-01 -- sh -c 'sudo kubeadm join 10.19.157.152:6443 --token 4kar3x.1d85mu95f7v90a08 --discovery-token-ca-cert-hash sha256:d3d8f62c208d515b169730b8ed594231a6659aa42e886548f565ff27bb788f3a'

... if you didn't remember or have copy, create a new token with the command:

multipass exec control-plane -- sh -c 'kubeadm token create --print-join-command'

Step 5 Use an instance

To open a shell prompt on an existing instance, execute the following command: multipass shell <VM_NAME>

Step 5.1 On second window, control-plane

multipass shell control-plane

## Inside VM control-plane
$ kubectl get nodes
NAME            STATUS     ROLES           AGE   VERSION
control-plane   Ready      control-plane   69m   v1.24.6
worker-01       Ready      <none>          21s   v1.24.6

$ kubectl run nginx --image=nginx
pod/nginx created

$ kubectl get pods -w
NAME    READY   STATUS              RESTARTS   AGE
nginx   0/1     ContainerCreating   0          11s
nginx   1/1     Running             0          12s

Step 6. Destroy

After you complete practice, you can delete the VMs. Assume you are still on the same directory as Step 1.

./destroy.sh