code: def run_on_all_sites(self, cmd, *args, **kwargs):
          
          r = self.local_renderer
          for _site, _data in iter_sites():
              r.env.SITE = _site
              with self.settings(warn_only=True):
                  r.run('export SITE={SITE}; export ROLE={ROLE}; '+cmd)
docs: Like run(), but re-runs the command for each site in the current role.