[Wlug] Automating RPM building

For my btbuilder project, I have a script to automatically tag a new version, put everything into an tgz, cross-compile to windows, and zip that up. Recently I've been building a .src.rpm for Fedora's copr as well. Actually the rpm is for inclusion in Fedora but I haven't gotten a sponsor yet so publishing to copr is best I can do: https://bugzilla.redhat.com/show_bug.cgi?id=1079064 I'd like to automate the building of this .src.rpm. Currently I copy the tgz to makerpm's rpmbuild/SOURCES and use rpmbuild as user makerpm. I'm trying to find a good way to automate that. Suggestions? I could use ssh with ssh-keygen but I'm wondering if there is a better way.