Merge pull request #499 from alexanderlz/master

Feature: Support Impala as DataSource

redash/query_runner/impala_ds.py

@@ -0,0 +1,159 @@
+import json
+import logging
+import sys
+
+from redash.query_runner import *
+from redash.utils import JSONEncoder
+
+logger = logging.getLogger(__name__)
+
+try:
+    from impala.dbapi import connect
+    from impala.error import DatabaseError, RPCError
+    enabled = True
+except ImportError, e:
+    logger.exception(e)
+    logger.warning("Missing dependencies. Please install impyla.")
+    logger.warning("You can use pip: pip install impyla")
+    enabled = False
+
+COLUMN_NAME = 0
+COLUMN_TYPE = 1
+
+types_map = {
+    'BIGINT': TYPE_INTEGER,
+    'TINYINT': TYPE_INTEGER,
+    'SMALLINT': TYPE_INTEGER,
+    'INT': TYPE_INTEGER,
+    'DOUBLE': TYPE_FLOAT,
+    'DECIMAL': TYPE_FLOAT,
+    'FLOAT': TYPE_FLOAT,
+    'REAL': TYPE_FLOAT,
+    'BOOLEAN': TYPE_BOOLEAN,
+    'TIMESTAMP': TYPE_DATETIME,
+    'CHAR': TYPE_STRING,
+    'STRING': TYPE_STRING,
+    'VARCHAR': TYPE_STRING
+}
+
+
+class Impala(BaseQueryRunner):
+    @classmethod
+    def configuration_schema(cls):
+        return {
+            "type": "object",
+            "properties": {
+                "host": {
+                    "type": "string"
+                },
+                "port": {
+                    "type": "number"
+                },
+                "protocol": {
+                    "type": "string",
+                    "title": "Please specify beeswax or hiveserver2"
+                },
+                "database": {
+                    "type": "string"
+                },
+                "use_ldap": {
+                    "type": "boolean"
+                },
+                "ldap_user": {
+                    "type": "string"
+                },
+                "ldap_password": {
+                    "type": "string"
+                },
+                "timeout": {
+                    "type": "number"
+                }
+            },
+            "required": ["host"]
+        }
+
+    @classmethod
+    def type(cls):
+        return "impala"
+
+    def __init__(self, configuration_json):
+        super(Impala, self).__init__(configuration_json)
+
+    def _run_query_internal(self, query):
+        results, error = self.run_query(query)
+
+        if error is not None:
+            raise Exception("Failed getting schema.")
+        return json.loads(results)['rows']
+
+    def get_schema(self):
+        try:
+            schemas_query = "show schemas;"
+
+            tables_query = "show tables in %s;"
+
+            columns_query = "show column stats %s;"
+
+            schema = {}
+            for schema_name in map(lambda a: a['name'], self._run_query_internal(schemas_query)):
+                for table_name in map(lambda a: a['name'], self._run_query_internal(tables_query % schema_name)):
+                    columns = map(lambda a: a['Column'], self._run_query_internal(columns_query % table_name))
+
+                    if schema_name != 'default':
+                        table_name = '{}.{}'.format(schema_name, table_name)
+
+                    schema[table_name] = {'name': table_name, 'columns': columns}
+        except Exception, e:
+            raise sys.exc_info()[1], None, sys.exc_info()[2]
+        return schema.values()
+
+    def run_query(self, query):
+
+        connection = None
+        try:
+            connection = connect(**self.configuration)
+
+            cursor = connection.cursor()
+
+            cursor.execute(query)
+
+            column_names = []
+            columns = []
+
+            for column in cursor.description:
+                column_name = column[COLUMN_NAME]
+                column_names.append(column_name)
+
+                columns.append({
+                    'name': column_name,
+                    'friendly_name': column_name,
+                    'type': types_map.get(column[COLUMN_TYPE], None)
+                })
+
+            rows = [dict(zip(column_names, row)) for row in cursor]
+
+            data = {'columns': columns, 'rows': rows}
+            json_data = json.dumps(data, cls=JSONEncoder)
+            error = None
+            cursor.close()
+        except DatabaseError as e:
+            logging.exception(e)
+            json_data = None
+            error = e.message
+        except RPCError as e:
+            logging.exception(e)
+            json_data = None
+            error = "Metastore Error [%s]" % e.message
+        except KeyboardInterrupt:
+            connection.cancel()
+            error = "Query cancelled by user."
+            json_data = None
+        except Exception as e:
+            logging.exception(e)
+            raise sys.exc_info()[1], None, sys.exc_info()[2]
+        finally:
+            connection.close()
+
+        return json_data, error
+
+register(Impala)

redash/query_runner/pg.py

@@ -93,7 +93,7 @@ def get_schema(self):
         results, error = self.run_query(query)
 
         if error is not None:
-           raise Exception("Failed getting schema.")
+            raise Exception("Failed getting schema.")
 
         results = json.loads(results)
 

redash/settings.py

@@ -101,6 +101,7 @@ def parse_boolean(str):
     'redash.query_runner.url',
     'redash.query_runner.influx_db',
     'redash.query_runner.presto',
+    'redash.query_runner.impala_ds',
 ])))
 
 # Features:

requirements.txt

@@ -29,4 +29,4 @@ click==3.3
 RestrictedPython==3.6.0
 wtf-peewee==0.2.3
 pysaml2==2.4.0
-pycrypto==2.6.1
+pycrypto==2.6.1