A Maven plugin for building and pushing Docker images.
You can use this plugin to create a Docker image with artifacts built from your Maven project. For example, the build process for a Java service can output a Docker image that runs the service.
You can specify the base image, entry point, cmd, maintainer and files you want to add to your
image directly in the pom, without needing a separate Dockerfile.
If you need VOLUME command(or any other not supported dockerfile command), then you will need
to create a Dockerfile and use the dockerDirectory element.
This example creates a new image named example, copies the project's jar file into the image,
and sets an entrypoint which runs the jar. Change VERSION GOES HERE to the latest tagged version.
<build>
<plugins>
...
<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<version>VERSION GOES HERE</version>
<configuration>
<imageName>example</imageName>
<baseImage>java</baseImage>
<entryPoint>["java", "-jar", "/${project.build.finalName}.jar"]</entryPoint>
<!-- copy the service's jar file from target into the root directory of the image -->
<resources>
<resource>
<targetPath>/</targetPath>
<directory>${project.build.directory}</directory>
<include>${project.build.finalName}.jar</include>
</resource>
</resources>
</configuration>
</plugin>
...
</plugins>
</build>
To use a Dockerfile, you must specify the dockerDirectory element. If specified, the
baseImage, maintainer, cmd and entryPoint elements will be ignored. The contents of the
dockerDirectory will be copied into ${project.build.directory}/docker. Use the resources
element to copy additional files, such as the service's jar file.
<build>
<plugins>
...
<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<version>VERSION GOES HERE</version>
<configuration>
<imageName>example</imageName>
<dockerDirectory>docker</dockerDirectory>
<resources>
<resource>
<targetPath>/</targetPath>
<directory>${project.build.directory}</directory>
<include>${project.build.finalName}.jar</include>
</resource>
</resources>
</configuration>
</plugin>
...
</plugins>
</build>
You can build an image with the above configurations by running this command.
mvn clean package docker:build
To push the image you just built to the registry, specify the pushImage flag.
mvn clean package docker:build -DpushImage
By default the plugin will try to connect to docker on localhost:2375. Set the DOCKER_HOST environment variable to connect elsewhere.
DOCKER_HOST=tcp://<host>:2375
You can also bind the build goal to the package phase, so the container will be built when you run
just mvn package. If you have a multi-module project where a sub-module builds an image, you
will need to do this binding so the image gets built when maven is run from the parent project.
<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<version>VERSION GOES HERE</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>build</goal>
</goals>
</execution>
</executions>
</plugin>
To remove the image named foobar run the following command:
mvn docker:removeImage -DimageName=foobar
For a complete list of configuration options run:
mvn com.spotify:docker-maven-plugin:<version>:help -Ddetail=true
To push an image to a private registry, Docker requires that the image tag
being pushed is prefixed with the hostname and port of the registry. For
example to push my-image to registry.example.com, the image needs to be
tagged as registry.example.com/my-image.
The simplest way to do this with docker-maven-plugin is to put the registry
name in the <imageName> field, for example
<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<configuration>
<imageName>registry.example.com/my-image</imageName>
...Then when pushing the image with either docker:build -DpushImage or
docker:push, the docker daemon will push to registry.example.com.
Alternatively, if you wish to use a short name in docker:build you can use
docker:tag to tag the just-built image with the full registry hostname. For
example:
<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<configuration>
<imageName>my-image</imageName>
...
</configuration>
<executions>
<execution>
<id>build-image</id>
<phase>package</phase>
<goals>
<goal>build</goal>
</goals>
</execution>
<execution>
<id>tag-image</id>
<phase>package</phase>
<goals>
<goal>tag</goal>
</goals>
<configuration>
<image>my-image</image>
<newName>registry.example.com/my-image</newName>
</configuration>
</execution>
</executions>
</plugin>To push to a private Docker image registry that requires authentication, you can put your
credentials in your Maven's global settings.xml file as part of the <servers></servers> block.
<servers>
<server>
<id>docker-hub</id>
<username>foo</username>
<password>secret-password</password>
<configuration>
<email>foo@foo.bar</email>
</configuration>
</server>
</servers>
Now use the server id in your project pom.xml.
<plugin>
<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<version>VERSION GOES HERE</version>
<configuration>
[...]
<serverId>docker-hub</serverId>
<registryUrl>https://index.docker.io/v1/</registryUrl>
</configuration>
</plugin>
</plugins>
<registryUrl></registryUrl> is optional and defaults to https://index.docker.io/v1/ in the
Spotify docker-client dependency.
Credentials can be encrypted using Maven's built in encryption function. Only passwords enclosed in curly braces will be considered as encrypted.
<servers>
<server>
<id>docker-hub</id>
<username>foo</username>
<password>{gc4QPLrlgPwHZjAhPw8JPuGzaPitzuyjeBojwCz88j4=}</password>
</server>
</servers>
Make sure Docker daemon is running and that you can do docker ps. Then run mvn clean test.
Commits to the master branch will trigger our continuous integration agent to build the jar and release by uploading to Sonatype. If you are a project maintainer with the necessary credentials, you can also build and release locally by running the below.
mvn release:clean
mvn release:prepare
mvn release:performBecause the plugin uses Maven properties named like
docker.build.defaultProfile, if you declare any other Maven property with the
name docker you will get a rather strange-looking error from Maven:
[ERROR] Failed to execute goal com.spotify:docker-maven-plugin:0.0.21:build (default) on project <....>:
Exception caught: system properties: docker has type STRING rather than OBJECT
To fix this, rename the docker property in your pom.xml.
Problem: when building the Docker image, Maven outputs an exception with a stacktrace like:
Caused by: com.spotify.docker.client.shaded.javax.ws.rs.InternalServerErrorException: HTTP 500 Internal Server Error
docker-maven-plugin communicates with your local Docker daemon using the HTTP
Remote API and any unexpected errors that the daemon encounters will be
reported as 500 Internal Server Error.
Check the Docker daemon log (typically at /var/log/docker.log or
/var/log/upstart/docker.log) for more details.
One common cause of 500 Internal Server Error is attempting to build an image
with a repository name containing uppercase characters, such as if the
<imageName> in the plugin's configuration refers to ${project.version} when
the Maven project version is ending in SNAPSHOT.
Consider putting the project version in an image tag (instead of repository
name) with the <dockerImageTags> configuration option instead.