Single Stage Dockerfile With Maven Spring Boot

A single-stage Dockerfile uses one image for everything: building the application and running it.

This is easy to understand, so it is a good first step before learning multi-stage Dockerfiles.

Single-stage example

FROM maven:3.9-eclipse-temurin-17
WORKDIR /app
COPY . .
RUN mvn clean package
EXPOSE 8080
CMD ["java", "-jar", "target/app.jar"]

This Dockerfile copies the source code, builds the project inside the image, and starts the generated JAR.

What happens during build

When you run:

docker build -t spring-single-stage:1.0 .

Docker:

1. Starts from a Maven image
2. Copies the full project
3. Runs Maven inside the image
4. Stores the built JAR in the image
5. Keeps Maven and build files in the final image

Why it is beginner friendly

Single-stage Dockerfiles are simple because everything happens in one place.

You do not need to install Maven locally. Docker uses the Maven base image to build the application.

The problem

The final image includes more than it needs.

It contains:

• Maven
• Source code
• Build cache
• Test files
• The final JAR

For running a Spring Boot app, you only need Java runtime and the JAR.

When to use it

Use single-stage builds for learning, experiments, and quick demos.

For production images, use multi-stage builds.

Written By: Shiva Srivastava