docs: def _discover_ks_version(self, url):
          '''
          Keystone API version discovery
          '''
          result = salt.utils.http.query(url, backend='requests', status=True, decode=True, decode_type='json')
          versions = json.loads(result['body'])
          try:
              links = [ver['links'] for ver in versions['versions']['values'] if ver['status'] == 'stable'][0] \
                      if result['status'] == 300 else versions['version']['links']
              resurl = [link['href'] for link in links if link['rel'] == 'self'][0]
              return self._get_version_from_url(resurl)
          except KeyError as exc:
              raise SaltCloudSystemExit('KeyError: key {0} not found in API response: {1}'.format(exc, versions))