spring-boot-docker

How to build a docker image for running a spring boot application using the dockerfile-maven-plugin from Spotify, with Docker Toolbox.

We need to have a Dockerfile — for the purpose of demonstration there’s a Dockerfile. Add Dockerfile into our root directory alongside our pom.xml.

Dockerfile

Start with a base image containing Java runtime

FROM dperezcabrera/openjdk11-alpine

Add Maintainer Info

MAINTAINER Zeeshan Alam Khan [email protected]

Add a volume pointing to /tmp

VOLUME /tmp

Make port 8080 available to the world outside this container

EXPOSE 8080

The application's jar file

ARG JAR_FILE=target/docker-example.jar

Add the application's jar to the container

ADD ${JAR_FILE} docker-example.jar

Run the jar file

ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/docker-example.jar"]

Next we will add some configuration into the pom.xml, specifically repository tag and an argument for the JAR_FILE which you can see we reference in the Dockerfile above.

spotify dockerfile maven plugin

 <plugin>
			<groupId>com.spotify</groupId>
			<artifactId>dockerfile-maven-plugin</artifactId>
			<version>1.4.13</version>
			<configuration>
				<repository>zeeshanalamkhan/docker-example</repository>
				<tag>${project.version}</tag>
				<dockerHost>https://192.168.99.100:2376</dockerHost>
				<dockerCertPath>C:/Users/<Your User name>/.docker/machine/machines/default
				</dockerCertPath>
				<buildArgs>
					<JAR_FILE>target/${project.build.finalName}.jar</JAR_FILE>
				</buildArgs>
			</configuration>
			<executions>
				<execution>
					<id>default</id>
					<phase>install</phase>
					<goals>
						<goal>build</goal>
						<goal>push</goal>
					</goals>
				</execution>
			</executions>
		</plugin>

Now run the project as maven build ->goal -> clean package dockerfile:build On completion we should see a message indicating the Docker image has been successfully created.

Once built, we can run our new Docker image as. docker run -p 8080:8080 docker-example:0.0.1-SNAPSHOT

and we can access our application from web browser or postman as 192.168.99.102:8080/hello/{any name}