Building Docker image using Spring Boot code

Dockerfile.springboot

## JDK
FROM eclipse-temurin:21-alpine AS builder

## install maven CLI
RUN apk add --no-cache maven

## container directory
WORKDIR /app

## copy the pom.xml and download the dependencies
COPY pom.xml .
RUN mvn dependency:go-offline -B

## copy the source code and build the application
COPY src ./src
RUN mvn package -DskipTests

## run the application
FROM eclipse-temurin:21-alpine

## set the working directory inside the container
WORKDIR /app

## copy the JAR file from the builder stage
COPY --from=builder /app/target/spring-docker-0.0.1.jar app.jar

## expose service port
EXPOSE 8080

## start service
ENTRYPOINT ["java","-jar","app.jar"]

Keep the above file in root directory of your Spring Boot project.

To build Docker image, execute the below command:

docker build -t <your_docker_image_name> .

To create a container out of it

docker run -p 8080:8080 <your_docker_image_name>