How to build docker images in multi-module maven project via spotify plugin?

I have a maven project that consists of 2 modules with the following structure:

pom.xml
  |
  x----module-1
  |      |
  |      x----pom.xml
  |
  x----module-2
         |
         x----pom.xml

I want to build both modules as docker images and push them to a docker registry.

Here's what I have in the child poms:

Module 1

<build>
    <finalName>module-1</finalName>
    <plugins>
        <plugin>
            <groupId>com.spotify</groupId>
            <artifactId>docker-maven-plugin</artifactId>
            <version>1.0.0</version>
            <configuration>
                <imageName>${project.artifactId}</imageName>
                <baseImage>openjdk:8-jre-alpine</baseImage>
                <entryPoint>["java", "-jar", "/opt/${project.build.finalName}.war"]</entryPoint>
                <serverId>docker-hub</serverId>
                <registryUrl>http://10.100.25.216:5000/v2/</registryUrl>
                <resources>
                    <resource>
                        <targetPath>/opt</targetPath>
                        <directory>${project.build.directory}</directory>
                        <include>${project.build.finalName}.war</include>
                    </resource>
                </resources>
            </configuration>
        </plugin>
    </plugins>
</build>

Module 2

<build>
    <finalName>module-2</finalName>
    <plugins>
        <plugin>
            <groupId>com.spotify</groupId>
            <artifactId>docker-maven-plugin</artifactId>
            <version>1.0.0</version>
            <configuration>
                <imageName>${project.artifactId}</imageName>
                <baseImage>openjdk:8-jre-alpine</baseImage>
                <entryPoint>["java", "-jar", "/opt/${project.build.finalName}.war"]</entryPoint>
                <serverId>docker-hub</serverId>
                <registryUrl>http://10.100.25.216:5000/v2/</registryUrl>
                <resources>
                    <resource>
                        <targetPath>/opt</targetPath>
                        <directory>${project.build.directory}</directory>
                        <include>${project.build.finalName}.war</include>
                    </resource>
                </resources>
            </configuration>
        </plugin>
    </plugins>
</build>

But when I build the project with the following command:

mvn clean package docker:build -DpushImage

I get the following error:

[ERROR] Failed to execute goal com.spotify:docker-maven-plugin:1.0.0:build (default) on project spotify: Exception caught: Must specify baseImage if dockerDirectory is null -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

As far as I know, I need to configure parent pom to run the submodule builds, but don't have a clue on how to do it.

P.S. I found solutions that were involving Dockerfile-s to the project, but I would prefer maven only version if possible, using the plugin only. Is there any way?