public String content() throws IllegalArgumentException {

        StringBuilder b = new StringBuilder();

        DockerFileKeyword.FROM.addTo(b, baseImage != null ? baseImage : DockerAssemblyManager.DEFAULT_DATA_BASE_IMAGE);
        if (maintainer != null) {
            DockerFileKeyword.MAINTAINER.addTo(b, maintainer);
        }

        addOptimisation();
        addEnv(b);
        addLabels(b);
        addPorts(b);

        addCopy(b);
        addWorkdir(b);
        addShell(b);
        addRun(b);
        addVolumes(b);

        addHealthCheck(b);

        addCmd(b);
        addEntryPoint(b);

        addUser(b);

        return b.toString();
    }
Create a Dockerfile following the format described in the
<a href="http://docs.docker.io/reference/builder/#usage">Docker reference manual</a>

@return the dockerfile create
@throws IllegalArgumentException if no src/dest entries have been added
src/main/java/io/fabric8/maven/docker/assembly/DockerFileBuilder.java