Deploying TypeScript on Kubernetes: A Basic Guide for Beginners

Deploying TypeScript on Kubernetes: A Basic Guide for Beginners

Modern web development is unthinkable without containerization and orchestration. If you write in TypeScript and want your application to run stably, scale automatically, and be fault-tolerant, Kubernetes (K8s) will become your best friend. In this guide, we will walk through step by step how to package a TypeScript application in Docker and deploy it in a Kubernetes cluster. The material is designed for beginners: no magic, only clear examples and explanations.

1. Preparing the TypeScript Application

Before thinking about Kubernetes, you need to ensure your application is ready to run in a container. Let's create a simple HTTP server using Express with TypeScript.

1.1. Project Initialization

Create a project folder and run the initialization:

mkdir my-ts-app && cd my-ts-app\nnpm init -y\nnpm install express\nnpm install -D typescript @types/node @types/express ts-node nodemon

1.2. TypeScript Configuration

Create a tsconfig.json file:

{\n  "compilerOptions": {\n    "target": "ES2020",\n    "module": "commonjs",\n    "outDir": "./dist",\n    "rootDir": "./src",\n    "strict": true,\n    "esModuleInterop": true,\n    "skipLibCheck": true\n  },\n  "include": ["src/**/*"],\n  "exclude": ["node_modules", "dist"]\n}

1.3. Application Code

Create a src folder and an index.ts file:

import express, { Request, Response } from 'express';\n\nconst app = express();\nconst PORT = process.env.PORT || 3000;\n\napp.get('/', (req: Request, res: Response) => {\n  res.json({ message: 'Hello from TypeScript on Kubernetes!' });\n});\n\napp.listen(PORT, () => {\n  console.log(`Server running on port ${PORT}`);\n});

1.4. Build and Run

Add scripts to package.json:

"scripts": {\n  "build": "tsc",\n  "start": "node dist/index.js",\n  "dev": "ts-node src/index.ts"\n}

Check local startup: npm run dev and open http://localhost:3000.

2. Containerization with Docker

Kubernetes works with containers. We need to create a Docker image of our TypeScript application.

2.1. Dockerfile

Create a Dockerfile in the project root:

FROM node:18-alpine AS builder\nWORKDIR /app\nCOPY package*.json ./\nRUN npm ci\nCOPY . .\nRUN npm run build\n\nFROM node:18-alpine AS production\nWORKDIR /app\nCOPY --from=builder /app/dist ./dist\nCOPY --from=builder /app/package*.json ./\nRUN npm ci --only=production\nEXPOSE 3000\nCMD ["node", "dist/index.js"]

We use multi-stage build: first compile TypeScript, then create a lightweight final image.

2.2. Building the Image

docker build -t my-ts-app:latest .

Check locally:

docker run -p 3000:3000 my-ts-app:latest

2.3. .dockerignore

To avoid copying unnecessary files, create a .dockerignore file:

node_modules\ndist\n.git\n*.md

3. Deploying to Kubernetes

Now that we have a Docker image, we can move on to Kubernetes. For local testing, I recommend Minikube or Kind.

3.1. Starting Minikube

minikube start --driver=docker\nminikube status

3.2. Loading the Image into Minikube

For Kubernetes to find our image, load it into the Minikube environment:

minikube image load my-ts-app:latest

3.3. Creating a Deployment

Create a deployment.yaml file:

apiVersion: apps/v1\nkind: Deployment\nmetadata:\n  name: my-ts-app-deployment\nspec:\n  replicas: 2\n  selector:\n    matchLabels:\n      app: my-ts