Setting Up a k3s Cluster on Multipass
This guide will walk you through the process of setting up a k3s Kubernetes cluster on Multipass, from creating the virtual machines to deploying k3s and joining the worker nodes to the control plane. The goal is to have an Kubernetes cluster that you can experiment and break without consequence.
Introduction
After encountering issues with network configurations using Minikube inside Multipass, I decided to explore an alternative lightweight Kubernetes setup using k3s. The following sections detail a step-by-step guide on setting up a k3s cluster using Multipass as the virtualization platform.
Initial Setup with Multipass
Finding Images
Before creating virtual machines, it’s useful to know what images are available:
multipass find
Image Aliases Version Description
20.04 focal 20240408 Ubuntu 20.04 LTS
22.04 jammy,lts 20240319 Ubuntu 22.04 LTS
23.10 mantic 20240410 Ubuntu 23.10
Blueprint Aliases Version Description
anbox-cloud-appliance latest Anbox Cloud Appliance
charm-dev latest A development and testing environment for charmers
docker 0.4 A Docker environment with Portainer and related tools
jellyfin latest Jellyfin is a Free Software Media System that puts you in control of managing and streaming your media.
minikube latest minikube is local Kubernetes
ros-noetic 0.1 A development and testing environment for ROS Noetic.
ros2-humble 0.1 A development and testing environment for ROS 2 Humble.
Creating VMs
Create one control node and two worker nodes using Ubuntu 23.10:
# Create the control node
multipass launch -c 1 -m 1g -d 4g -n k3s-control 23.10
# Create worker nodes
multipass launch -c 1 -m 1g -d 4g -n k3s-worker-1 23.10
multipass launch -c 1 -m 1g -d 4g -n k3s-worker-2 23.10
Flags Explanation:
-c: Number of CPUs-m: Amount of memory-d: Disk space-n: Name of the node
Verify Node Status
Ensure all nodes are running:
multipass list
Name State IPv4 Image
k3s-control Running 192.168.64.16 Ubuntu 23.10
k3s-worker-1 Running 192.168.64.17 Ubuntu 23.10
k3s-worker-2 Running 192.168.64.19 Ubuntu 23.10
Deploying k3s
Install k3s on the Control Node
Run the k3s installation script on the control node:
multipass exec k3s-control -- bash -c "curl -sfL https://get.k3s.io | sh -"
Set Up Node Token and IP Environment Variables
Retrieve and save the node token and IP address of the control node:
# Save the token
TOKEN=$(multipass exec k3s-control sudo cat /var/lib/rancher/k3s/server/node-token)
# Save the IP address
IP=$(multipass info k3s-control | grep IPv4 | awk '{print $2}')
Configure Worker Nodes
Create a bash script to join the worker nodes to the cluster:
#!/bin/bash
# Assign passed arguments to variables
IP=$1
TOKEN=$2
for f in 1 2; do
multipass exec k3s-worker-$f -- bash -c "curl -sfL https://get.k3s.io | K3S_URL='https://${IP}:6443' K3S_TOKEN='${TOKEN}' sh -" &
done
wait
Run the script with IP and token:
./install_k3s_workers.sh $IP $TOKEN
Verifying the Cluster
Log in to the control node and check the cluster nodes:
multipass exec k3s-control -- bash
sudo kubectl get nodes
Clean Up
When done, you can stop and delete your instances:
# Stop instances
multipass stop k3s-control k3s-worker-1 k3s-worker-2
# Delete instances
multipass delete k3s-control k3s-worker-1 k3s-worker-2
multipass purge
Where to Go From Here
Now that you have a k3s cluster running on Multipass, there are several exciting directions you can take to expand your knowledge and utilization of your new Kubernetes environment:
1. Deploy Real-World Applications
Experiment by deploying real-world applications into your cluster. This could range from simple web applications to more complex multi-tier applications involving databases, caching, and front-end services. You can use existing Docker images or create your own.
2. Explore Kubernetes Features
Dive deeper into Kubernetes functionalities such as:
- Ingress Controllers: Set up an Ingress controller like Traefik or Nginx to manage access to the services in your cluster from outside.
- Persistent Volumes: Implement persistent storage solutions to understand how data can be managed and persisted in Kubernetes.
- Advanced Scheduling: Learn about pod affinity, taints, and tolerations for advanced scheduling of workloads.
3. Implement DevOps Practices
Utilize your cluster to implement full CI/CD pipelines which could help in automating the deployment of applications directly from source control:
- Continuous Integration Tools: Set up Jenkins or GitLab CI to automate the building and testing of your applications.
- Continuous Deployment: Use Argo CD or Flux for GitOps-based deployments to continuously deploy updates to your applications.
4. Monitoring and Logging
Set up monitoring and logging to maintain the health of your cluster:
- Monitoring: Install Prometheus and Grafana for monitoring the performance of your cluster and applications.
- Logging: Set up a stack like ELK (Elasticsearch, Logstash, Kibana) or Loki to aggregate and analyze logs from your cluster.
5. Learning and Experimentation
- Security Practices: Implement network policies, manage secrets effectively, and use service accounts to improve the security of your cluster.
- Simulate Failures: Use tools like Chaos Mesh to introduce failures into the cluster to learn how Kubernetes and your applications respond to unexpected disruptions.
Conclusion
Setting up a k3s cluster on Multipass provides a lightweight and flexible development environment suitable for various use cases, from learning Kubernetes to developing cloud-native applications. It’s the perfect environment to fail safely in.