How to Set Up a K3s Cluster With One Server and Two Agents?

To set up a k3s cluster with one server and two agents using Pulumi in TypeScript, we will follow these steps:

1. Introduction: Provide an overview of the solution and the key services involved.
2. Step-by-Step Explanation: Detail the steps required to set up the k3s cluster.
3. Key Points: Highlight the important aspects of the setup.
4. Conclusion: Summarize the solution and its benefits.

Introduction

In this solution, we will set up a lightweight Kubernetes cluster using k3s, which is a minimalistic distribution of Kubernetes. We will use Pulumi, an infrastructure as code tool, to automate the deployment. The key services involved are the k3s server and k3s agents. The server will act as the control plane, while the agents will join the cluster as worker nodes.

Step-by-Step Explanation

1. Install Pulumi and Dependencies: Ensure you have Pulumi and the necessary dependencies installed.
2. Create a New Pulumi Project: Initialize a new Pulumi project in TypeScript.
3. Define Infrastructure: Write the Pulumi code to define the k3s server and agents.
4. Deploy the Infrastructure: Use Pulumi to deploy the k3s cluster.

Key Points

• Lightweight Kubernetes: k3s is a lightweight distribution of Kubernetes, making it ideal for edge and IoT use cases.
• Infrastructure as Code: Pulumi allows us to define and manage our infrastructure using code, enabling version control and automation.
• Scalability: The setup can be easily scaled by adding more agents to the cluster.

Conclusion

By following this guide, we have successfully set up a k3s cluster with one server and two agents using Pulumi in TypeScript. This setup provides a lightweight and scalable Kubernetes environment that can be used for various applications, especially in edge and IoT scenarios.

Full Code Example

import * as pulumi from "@pulumi/pulumi";
import * as k8s from "@pulumi/kubernetes";

// Create a k3s server
const server = new k8s.core.v1.Pod("k3s-server", {
    metadata: { name: "k3s-server" },
    spec: {
        containers: [{
            name: "k3s-server",
            image: "rancher/k3s:v1.21.4-k3s1",
            args: ["server"],
            ports: [{ containerPort: 6443 }],
        }],
    },
});

// Create a service for the k3s server
const serverService = new k8s.core.v1.Service("k3s-server-service", {
    metadata: { name: "k3s-server-service" },
    spec: {
        selector: server.metadata.apply(m => ({ name: m.name })),
        ports: [{ port: 6443, targetPort: 6443 }],
    },
});

// Create k3s agents
const agent1 = new k8s.core.v1.Pod("k3s-agent1", {
    metadata: { name: "k3s-agent1" },
    spec: {
        containers: [{
            name: "k3s-agent1",
            image: "rancher/k3s:v1.21.4-k3s1",
            args: ["agent", "--server", serverService.spec.clusterIP],
        }],
    },
});

const agent2 = new k8s.core.v1.Pod("k3s-agent2", {
    metadata: { name: "k3s-agent2" },
    spec: {
        containers: [{
            name: "k3s-agent2",
            image: "rancher/k3s:v1.21.4-k3s1",
            args: ["agent", "--server", serverService.spec.clusterIP],
        }],
    },
});

export const serverIp = serverService.spec.clusterIP;
export const agent1Ip = agent1.status.podIP;
export const agent2Ip = agent2.status.podIP;