How does Spring Boot 4 support containerised deployments with Docker?

# Option 1: Buildpacks (recommended -- no Dockerfile needed)
# Maven:
./mvnw spring-boot:build-image
# Produces: docker.io/library/order-service:1.0.0

# With custom image name and registry:
./mvnw spring-boot:build-image \
  -Dspring-boot.build-image.imageName=gcr.io/my-project/order-service:1.0.0

# Native image with Buildpacks:
./mvnw spring-boot:build-image -Pnative

# Option 2: Traditional Dockerfile with Layered JAR
# First, enable layered JAR:
<configuration>
    <layers>
        <enabled>true</enabled>
    </layers>
</configuration>

# Dockerfile (multi-stage, layered JAR):
FROM eclipse-temurin:17-jre AS builder
WORKDIR /app
COPY target/*.jar app.jar
RUN java -Djarmode=tools -jar app.jar extract --layers --launcher

FROM eclipse-temurin:17-jre
WORKDIR /app
# Copy layers in order of least-to-most frequently changed:
COPY --from=builder /app/extracted/dependencies ./
COPY --from=builder /app/extracted/spring-boot-loader ./
COPY --from=builder /app/extracted/snapshot-dependencies ./
COPY --from=builder /app/extracted/application ./
EXPOSE 8080
ENTRYPOINT ["java", "-jar", "app.jar"]

# Docker Compose for local development:
# compose.yml (Spring Boot 4 auto-detects compose.yml):
services:
  postgres:
    image: postgres:17
    environment:
      POSTGRES_DB: orders
      POSTGRES_USER: dev
      POSTGRES_PASSWORD: dev
    ports: ["5432:5432"]
  redis:
    image: redis:8
    ports: ["6379:6379"]
# spring.docker.compose.enabled=true (default) auto-starts compose services