'Gets the urls for the packages specified in pkg
:type pkg: KojiPkgSpec
:param pkg: a package specification
:type arch: string
:param arch: packages built for this architecture, but also including
architecture independent (noarch) packages'

def get_pkg_urls(self, pkg, arch=None):

    info = self.get_pkg_info(pkg)
    rpms = self.get_pkg_rpm_info(pkg, arch)
    rpm_urls = []
    base_url = self.get_pkg_base_url()
    for rpm in rpms:
        rpm_name = koji.pathinfo.rpm(rpm)
        url = ('%s/%s/%s/%s/%s' % (base_url, info['package_name'], info['version'], info['release'], rpm_name))
        rpm_urls.append(url)
    return rpm_urls
