private void setDockerHostAddressProperty(DockerAccessContext dockerAccessContext, String dockerUrl) throws MojoFailureException {
        Properties props = dockerAccessContext.getProjectProperties();
        if (props.getProperty("docker.host.address") == null) {
            final String host;
            try {
                URI uri = new URI(dockerUrl);
                if (uri.getHost() == null && (uri.getScheme().equals("unix") || uri.getScheme().equals("npipe"))) {
                    host = "localhost";
                } else {
                    host = uri.getHost();
                }
            } catch (URISyntaxException e) {
                throw new MojoFailureException("Cannot parse " + dockerUrl + " as URI: " + e.getMessage(), e);
            }
            props.setProperty("docker.host.address", host == null ? "" : host);
        }
    }
Return a list of providers which could delive connection parameters from
calling external commands. For this plugin this is docker-machine, but can be overridden
to add other config options, too.

@return list of providers or <code>null</code> if none are applicable
src/main/java/io/fabric8/maven/docker/service/DockerAccessFactory.java