Docker for Spring Boot Developers

Containerizing your Java applications has never been easier. In this guide we teach you how to do it step by step.

Basic Dockerfile

FROM eclipse-temurin:21-jdk-alpine AS build
WORKDIR /app
COPY . .
RUN ./gradlew bootJar

FROM eclipse-temurin:21-jre-alpine
COPY --from=build /app/build/libs/*.jar app.jar
ENTRYPOINT ["java", "-jar", "/app.jar"]

Multi-stage Build

Using multi-stage builds significantly reduces the final image size.

Benefits

• Portability: Your application works the same in any environment
• Isolation: No dependency conflicts
• Scalability: Easy to replicate in Kubernetes

Conclusion

Docker is essential for any modern Spring Boot project.