code: def es_version(self, url):
          
  
          try:
              res = self.grimoire_con.get(url)
              res.raise_for_status()
              major = res.json()['version']['number'].split(".")[0]
          except Exception:
              logger.error("Error retrieving Elasticsearch version: " + url)
              raise
          return major
docs: Get Elasticsearch version.
  
          Get the version of Elasticsearch. This is useful because
          Elasticsearch and Kibiter are paired (same major version for 5, 6).
  
          :param url: Elasticseearch url hosting Kibiter indices
          :returns:   major version, as string