What Docker base image (`FROM`) for Java Spring Boot?

There's a nice documentation on how to integrate Spring-Boot with Docker: https://spring.io/guides/gs/spring-boot-docker/

Basically you define your dockerfile in src/main/docker/Dockerfile and configure the docker-maven-plugin like this:

<build>
<plugins>
    <plugin>
        <groupId>com.spotify</groupId>
        <artifactId>docker-maven-plugin</artifactId>
        <version>0.4.11</version>
        <configuration>
            <imageName>${docker.image.prefix}/${project.artifactId}</imageName>
            <dockerDirectory>src/main/docker</dockerDirectory>
            <resources>
                <resource>
                    <targetPath>/</targetPath>
                    <directory>${project.build.directory}</directory>
                    <include>${project.build.finalName}.jar</include>
                </resource>
            </resources>
        </configuration>
    </plugin>
</plugins>

Dockerfile:

FROM frolvlad/alpine-oraclejre8:slim
VOLUME /tmp
ADD gs-spring-boot-docker-0.1.0.jar app.jar
RUN sh -c 'touch /app.jar'
ENV JAVA_OPTS=""
ENTRYPOINT [ "sh", "-c", "java $JAVA_OPTS -Djava.security.egd=file:/dev/./urandom -jar /app.jar" ]

Note that in this example FROM frolvlad/alpine-oraclejre8:slim is a small-footprinted image which is based on Alpine Linux.

You should also be able to use the standard Java 8 image (which is based on Debian and might have an increased footprint) as well. An extensive list of available Java Baseimages can be found here: https://github.com/docker-library/docs/tree/master/openjdk.

I am using the fabric plugin which uses the base docker image fabric8/java-alpine-openjdk8-jdk:1.2. There is no need for a Dockerfile, it is created by the plugin.

<build>
    <finalName>${project.artifactId}-${project.version}</finalName>
    <plugins>

        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.3</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>

        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>

        <plugin>
            <groupId>io.fabric8</groupId>
            <artifactId>fabric8-maven-plugin</artifactId>
            <version>3.2.28</version>
        </plugin>

    </plugins>
</build>

Targets are fabric8:build to create docker image and fabric8:push to push docker image registry.

mvn clean install fabric8:build fabric8:push