@QueryParameter URL serverUrl
) throws IOException, ServletException, DockerException {
DockerClient dc = DockerClient.builder().withUrl(serverUrl.toString()).build();
Version version = dc.system().version();
if( version.getVersionComponents()[0] < 1 )
return FormValidation.error("Docker host is " + version.getVersion() + " which is not supported.");
return FormValidation.ok("Version = " + version.getVersion());
}