vercel-spring adalah Vercel Community Runtime untuk Spring Boot. Dengan GraalVM Native Image, aplikasi Spring Boot kamu bisa jalan di Vercel sebagai serverless function — cold start di bawah 500ms.

📦 Installation

npm i -g vercel

Tidak perlu install vercel-spring secara lokal. Cukup referensikan di vercel.json.

🚀 Quick Start

1. Struktur project

my-spring-app/
├── api/
│   └── index.java          # Marker entrypoint
├── src/
│   └── main/
│       ├── java/
│       └── resources/
├── pom.xml
├── vercel.json
└── .vercelignore

2. api/index.java (marker file)

// Marker file for Vercel Spring Boot runtime

3. vercel.json

{
  "functions": {
    "api/index.java": {
      "runtime": "[email protected]",
      "memory": 3008,
      "maxDuration": 30
    }
  },
  "routes": [
    { "src": "/(.*)", "dest": "/api/index.java" }
  ]
}

4. pom.xml — tambahkan native profile

<profile>
    <id>native</id>
    <build>
        <plugins>
            <plugin>
                <groupId>org.graalvm.buildtools</groupId>
                <artifactId>native-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <id>build-native</id>
                        <goals><goal>compile</goal></goals>
                        <phase>package</phase>
                    </execution>
                </executions>
                <configuration>
                    <imageName>${project.artifactId}</imageName>
                    <buildArgs>
                        <!--
                          NOTE: --no-fallback is intentionally omitted.
                          It causes native-image to fail if ANY reachability
                          metadata is missing. For serverless deployment, a
                          fallback image is acceptable.
                        -->
                        <buildArg>--enable-url-protocols=http</buildArg>
                    </buildArgs>
                </configuration>
            </plugin>
        </plugins>
    </build>
</profile>

5. Deploy

vercel --prod

Done. 🎉

🔧 How It Works

                          Vercel Platform
                               │
                     ┌─────────▼─────────┐
                     │   HTTP Request     │
                     └─────────┬─────────┘
                               │
                     ┌─────────▼─────────┐
                     │  launcher.mjs      │  (Node.js Lambda handler)
                     │  (keep-alive)      │
                     └─────────┬─────────┘
                               │ spawn / proxy
                     ┌─────────▼─────────┐
                     │ spring-app.bin     │  (GraalVM native image)
                     │ Spring Boot App    │
                     └───────────────────┘

| Tahap | Proses | |---|---| | Build | Deteksi project → install GraalVM → build native image (mvn -Pnative native:compile / gradle nativeCompile) | | Runtime | Node.js launcher spawn native binary, proxy HTTP request, 5 menit keep-alive untuk reuse |

✨ Features

• ✅ Zero configuration — auto-detect Java version & build system (Maven/Gradle)
• ✅ Multi-Java — mendukung Java 17, 21, 22, 23, 24, 25
• ✅ Cold start cepat — ~100-500ms (vs 5-15s di JVM biasa)
• ✅ Auto-download toolchain — GraalVM, Maven, Gradle di-download otomatis
• ✅ H2 friendly — auto-exclude konfigurasi yang bikin warning di native-image

📁 Contoh Project

Lihat example/ untuk project Spring Boot lengkap yang siap deploy.

⚠️ Limitations

| Item | Detail | |---|---| | Cold start | ~100-500ms (native image) | | Package size | ~50-70MB (masih di bawah limit Vercel 250MB) | | Timeout | Atur via maxDuration di vercel.json (maks 900s) | | State | Setiap Lambda instance bersifat ephemeral |

🛠 Development

git clone https://github.com/awand795/vercel-spring.git
cd vercel-spring
npm install
npm run build

🤝 Contributing

Lihat CONTRIBUTING.md untuk panduan kontribusi (tersedia dalam Bahasa Indonesia dan English).

📄 License

MIT