Lesson 40 • Advanced

Deployment & Packaging

Your code is only useful when it's running in production. This lesson covers the entire path from source code to live application — creating executable JARs, containerizing with Docker, deploying to cloud platforms, and setting up CI/CD pipelines that ship code automatically.

Before You Start

You should know Maven & Gradle (build tools create your JARs) and Modular Java (jlink for slim runtimes). Basic command-line familiarity is assumed.

What You'll Learn

✅ Fat JARs and executable JARs with Maven/Gradle
✅ Docker containerization for Java apps
✅ Multi-stage Docker builds for smaller images
✅ Cloud deployment: AWS, GCP, Azure
✅ CI/CD pipelines with GitHub Actions
✅ Health checks and monitoring in production

1️⃣ Deployment Options

Analogy: Deploying is like shipping a package. A JAR is the product. Docker puts it in a standardized container. Kubernetes is the fleet of trucks managing delivery. CI/CD is the automated assembly line.

Method	Pros	Best For
JAR on VM	Simple, direct	Small apps
Docker	Consistent, portable	Most production apps
Kubernetes	Auto-scaling, self-healing	Microservices at scale
GraalVM Native	10ms startup, low memory	Serverless, CLIs

Try It: Docker Multi-Stage Build

Try it Yourself »

JavaScript

// 💡 Try modifying this code and see what happens!
// Docker multi-stage build simulation

console.log("=== Docker Multi-Stage Build ===\n");

// 1. The problem with single-stage
console.log("1. THE PROBLEM — Single Stage:");
let singleStage = { jdk: 400, maven: 200, source: 5, deps: 150, total: 755 };
console.log("  JDK:       " + singleStage.jdk + "MB");
console.log("  Maven:     " + singleStage.maven + "MB");
console.log("  Source:    " + singleStage.source + "MB");
console.log("  Deps:     
...

2️⃣ CI/CD Pipelines

Analogy: CI/CD is like a factory assembly line. Every time a developer pushes code, it automatically gets compiled, tested, packaged, and deployed. No manual steps, no "works on my machine" — if the pipeline passes, the code is production-ready.

CI (Continuous Integration): Compile → Test → Code quality check (every push)

CD (Continuous Delivery): Build artifact → Deploy to staging → Manual approval

CD (Continuous Deployment): Same, but deploys to production automatically

Try It: CI/CD Pipeline Simulation

Try it Yourself »

JavaScript

// 💡 Try modifying this code and see what happens!
// CI/CD Pipeline simulation

console.log("=== CI/CD Pipeline ===\n");

// Simulate pipeline stages
function runStage(name, durationMs, successRate) {
  let success = Math.random() < successRate;
  return { name, duration: durationMs, success, 
    message: success ? "✅ passed" : "❌ failed" };
}

// Pipeline definition
console.log("1. GITHUB ACTIONS PIPELINE:");
console.log(`  name: Java CI/CD
  on: [push, pull_request]
  jobs:
    build:
     
...

Common Mistakes

⚠️ Not using multi-stage Docker builds: Build image is 800MB, runtime should be 80MB
⚠️ Secrets in Dockerfiles: Use environment variables, Docker secrets, or a vault
⚠️ No health checks: Without /actuator/health, orchestrators can't restart crashed services
⚠️ No graceful shutdown: Configure server.shutdown=graceful for in-flight requests

Production Checklist

💡 ✅ Health endpoint configured (/actuator/health)
💡 ✅ Environment-specific configs via Spring Profiles
💡 ✅ Structured JSON logging for log aggregation
💡 ✅ Graceful shutdown enabled
💡 ✅ Resource limits set in Docker/K8s
💡 ✅ Secrets in environment variables, never hardcoded

Try It: Production Health & Monitoring

Try it Yourself »

JavaScript

// 💡 Try modifying this code and see what happens!
// Production health checks and monitoring

console.log("=== Production Health & Monitoring ===\n");

// 1. Health check endpoint
console.log("1. SPRING BOOT ACTUATOR HEALTH:");
let health = {
  status: "UP",
  components: {
    db: { status: "UP", details: { database: "PostgreSQL", validationQuery: "isValid()" } },
    diskSpace: { status: "UP", details: { total: "500GB", free: "320GB", threshold: "10MB" } },
    redis: { status: "UP", details
...

📋 Quick Reference

Task	Command	Notes
Package	mvn clean package	Creates JAR in target/
Run JAR	java -jar app.jar	Executable fat JAR
Docker build	docker build -t app .	Multi-stage builds
GraalVM	native-image -jar app.jar	~10ms startup
jlink	jlink --add-modules	Custom slim JRE

🎉 Lesson Complete!

You can now deploy Java apps from local development to production cloud environments! Next: Logging — professional logging with SLF4J and Logback.

Deployment & Packaging

Before You Start

What You'll Learn

1️⃣ Deployment Options

Try It: Docker Multi-Stage Build

2️⃣ CI/CD Pipelines

Try It: CI/CD Pipeline Simulation

Common Mistakes

Production Checklist

Try It: Production Health & Monitoring

📋 Quick Reference

🎉 Lesson Complete!

Cookie & Privacy Settings