Cassandra DS for redash

cassandra.py

import sys
import logging

from redash.query_runner import *

logger = logging.getLogger(__name__)

class Cassandra(BaseQueryRunner):
    @classmethod
    def configuration_schema(cls):
        return {
            'type': 'object',
            'properties': {
                'host': {
                    'type': 'string',
                },
                'port': {
                    'type': 'number',
                    'default': 9042,
                },
                'Keyspace': {
                    'type': 'string',
                    'title': 'Keyspace name'
                }
            },
            'required': ['Keyspace']
        }

    @classmethod
    def name(cls):
        return "cassandra"

    @classmethod
    def enabled(cls):
        try:
            from cassandra.cluster import Cluster
        except ImportError:
            return False

        return True

    def _get_tables(self, schema):
        query = """
        select columnfamily_name from system.schema_columnfamilies where keyspace_name = '{}';
        """.format(self.configuration['Keyspace'])

        results, error = self.run_query(query)
        return results

    def run_query(self, query):
        from cassandra.cluster import Cluster
        connection = None
        try:
            connection = Cluster([self.configuration.get('host', '')])
            session = connection.connect()
            logger.debug("Cassandra running query: %s", query)
            row = session.execute(query)

            CF = []
            count = 0
            for _ in row:
                CF.append(row[count[0]])
                couny += 1

                error = "No data was returned."

            session.close()
        except cassandra.cluster.Error, e:
            error = e.args[1]
        except KeyboardInterrupt:
            error = "Query cancelled by user."
        except Exception as e:
            raise sys.exc_info()[1], None, sys.exc_info()[2]
        finally:
            if connection:
                connection.close()

        return CF

register(Cassandra)