Init the connection to the InfluxDB server.

def init(self):
        """Init the connection to the InfluxDB server."""
        if not self.export_enable:
            return None

        try:
            db = InfluxDBClient(host=self.host,
                                port=self.port,
                                username=self.user,
                                password=self.password,
                                database=self.db)
            get_all_db = [i['name'] for i in db.get_list_database()]
        except InfluxDBClientError as e:
            logger.critical("Cannot connect to InfluxDB database '%s' (%s)" % (self.db, e))
            sys.exit(2)

        if self.db in get_all_db:
            logger.info(
                "Stats will be exported to InfluxDB server: {}".format(db._baseurl))
        else:
            logger.critical("InfluxDB database '%s' did not exist. Please create it" % self.db)
            sys.exit(2)

        return db