setup-springboot

Spring Boot 3.5.9 — Build and Deploy

Build and deploy a Spring Boot 3.5.9 REST API application. Provides the foundation for Datadog APM instrumentation (see springboot-dd-tracer skill).

The sample application provides three REST API endpoints with different logging destinations and random HTTP status codes (30% 2XX, 40% 4XX, 30% 5XX). See ../springboot-dd-tracer/README.md for the full application documentation.

Prerequisites

• Java 17 or Docker
• kubectl (for Kubernetes deployment)
• A Kubernetes cluster (see aws-ec2 or gcp-gke plugins)

Instructions

The full application source and documentation is in ../springboot-dd-tracer/references/. Key steps:

Option A: Maven (local development)

cd ../springboot-dd-tracer/references/
./mvnw clean package
./mvnw spring-boot:run

The application starts on http://localhost:8080.

Option B: Docker

cd ../springboot-dd-tracer/references/
docker build -t springboot3dot5dot9-sandbox:0.0.1-SNAPSHOT .
docker run -p 8080:8080 springboot3dot5dot9-sandbox:0.0.1-SNAPSHOT

Option C: Kubernetes (production)

cd ../springboot-dd-tracer/references/

# Build for linux/amd64 and push to registry
docker buildx build --platform linux/amd64 \
  -t <REGISTRY>/springboot3dot5dot9-sandbox:0.0.1-SNAPSHOT --push .

# Deploy
kubectl apply -f k8s/
kubectl rollout status deployment/springboot3dot5dot9-sandbox

Test the endpoints

# GET endpoint
curl http://localhost:8080/api/data

# POST endpoint
curl -X POST http://localhost:8080/api/submit \
  -H "Content-Type: application/json" \
  -d '{"key": "test"}'

# PUT endpoint
curl -X PUT http://localhost:8080/api/update -v

Validation

# Verify app is running
curl -s -o /dev/null -w "%{http_code}" http://localhost:8080/actuator/health
# Expected: 200

# Verify all three endpoints respond
curl -s http://localhost:8080/api/data | head -1
# Expected: JSON response with randomNumber, loremIpsum, statusCode

# For Kubernetes: verify pods are ready
kubectl get pods -l app=springboot3dot5dot9-sandbox
kubectl rollout status deployment/springboot3dot5dot9-sandbox

Troubleshooting

Port 8080 already in use

Cause: Another process is using port 8080. Fix: lsof -i :8080 to find it, then kill or change port in application.properties.

Maven build fails

Cause: Wrong Java version or corrupted cache. Fix: Verify java -version shows 17.x, then ./mvnw clean and retry.

Kubernetes pods stuck in CrashLoopBackOff

Cause: JVM startup exceeds probe timeout, or image pull failure. Fix: Check logs: kubectl logs -l app=springboot3dot5dot9-sandbox. The startup probe allows up to 70s for JVM boot.