private File getHostDirectory(String hostPath) {
        File projectBaseDirectory = project.getBasedir();
        if (hostPath == null) {
            return projectBaseDirectory;
        }
        File hostDirectory = new File(hostPath);
        if (hostDirectory.isAbsolute()) {
            return hostDirectory;
        }
        return new File(projectBaseDirectory, hostPath);
    }
Whether to copy from all containers matching configured images or only from the newest ones.
src/main/java/io/fabric8/maven/docker/CopyMojo.java