kenshoo/gradle-fpm-plugin — pull request #7 by pepov (2013-09-05 13:55:31+00:00)
Title: Add support for fpm --force option. 

Available since 0.4.32 https://github.com/jordansissel/fpm/commit/05dceea5f623d9feac9c27cd046809eaf36ea904

Note:
afaik @Input and @OutputDirectory annotations work only on tasks, not extensions.