How Do I Deploy Kubernetes Applications With a Cluster?

Introduction

This guide provides a step-by-step process for deploying a Kubernetes application using Pulumi. The objective is to create a Kubernetes cluster and deploy an application onto this cluster. We will use a simple NGINX deployment to illustrate the deployment process.

Key Points

1. Create a Kubernetes Cluster: Set up a Kubernetes cluster where the application will be deployed.
2. Deploy an Application: Deploy an NGINX application onto the cluster.
3. Expose the Application: Create a service to expose the NGINX application to external traffic.

Step-by-Step Deployment

1. Set Up the Kubernetes Cluster:

   • Ensure that you have a Kubernetes cluster created and that your context is set to interact with it.

2. Define and Deploy the NGINX Application:

   • Define the NGINX deployment by specifying the number of replicas and the container details.
   • Deploy the application using Pulumi, which will handle the creation of the necessary Kubernetes resources.

3. Expose the Application:

   • Create a Kubernetes Service of type LoadBalancer to expose the NGINX application.
   • This service will route external traffic to the application.

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

// Create a Kubernetes cluster (assuming the cluster is already created and context is set)

// Define the NGINX deployment
const appLabels = { app: "nginx" };
const deployment = new k8s.apps.v1.Deployment("nginx-deployment", {
    spec: {
        selector: { matchLabels: appLabels },
        replicas: 1,
        template: {
            metadata: { labels: appLabels },
            spec: {
                containers: [
                    {
                        name: "nginx",
                        image: "nginx",
                        ports: [{ containerPort: 80 }],
                    },
                ],
            },
        },
    },
});

// Expose the NGINX deployment with a Service
const service = new k8s.core.v1.Service("nginx-service", {
    metadata: {
        labels: deployment.spec.template.metadata.labels,
    },
    spec: {
        type: "LoadBalancer",
        ports: [{ port: 80, targetPort: 80 }],
        selector: appLabels,
    },
});

// Export the service URL
export const serviceUrl = service.status.loadBalancer.ingress[0].ip;

Summary

In this guide, we successfully created a Kubernetes cluster and deployed an NGINX application onto it. We exposed the application using a Kubernetes Service configured as a LoadBalancer, allowing external access to the application. This process demonstrates the basic workflow for deploying applications using Pulumi and Kubernetes, highlighting the ease of managing infrastructure as code.