code: def upgrade(self, full=0):
          
          full = int(full)
          r = self.local_renderer
          packager = self.packager
          if packager == APT:
              r.sudo('DEBIAN_FRONTEND=noninteractive apt-get -yq upgrade')
              if full:
                  r.sudo('DEBIAN_FRONTEND=noninteractive apt-get dist-upgrade -yq')
          elif packager == YUM:
              raise NotImplementedError
          else:
              raise Exception('Unknown packager: %s' % (packager,))
docs: Updates/upgrades all system packages.