nuclearpinguin commented on a change in pull request #6604: [AIRFLOW-5920] *DRAFT* Neo4j operator and hook URL: https://github.com/apache/airflow/pull/6604#discussion_r349943509
########## File path: airflow/contrib/hooks/neo4j_hook.py ########## @@ -0,0 +1,93 @@ +# -*- coding: utf-8 -*- +# +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. + +from airflow.exceptions import AirflowException +from airflow.hooks.base_hook import BaseHook +from neo4j import GraphDatabase + + +class Neo4JHook(BaseHook): + """ + Interact with Neo4J. + This class is a thin wrapper around the neo4j python library. + """ + _n4j_conn_id = None + + def __init__(self, n4j_conn_id='n4j_default', *args, **kwargs): + super().__init__() + self._n4j_conn_id = n4j_conn_id + + @staticmethod + def get_config(n4j_conn_id): + """ + Obtain the Username + Password from the Airflow connection definition + Store them in _config dictionary as: + credentials = a tuple of username/password eg. ("username", "password") + host = String for Neo4J URI eg. "bolt://1.1.1.1:7687" + :return: dictionary with configuration values + """ + config = {} + if n4j_conn_id: + # Initialize with empty dictionary + connection_object = Neo4JHook.get_connection(n4j_conn_id) + if connection_object.login and connection_object.host: + config['credentials'] = connection_object.login, connection_object.password + config['host'] = "bolt://{0}:{1}".format(connection_object.host, connection_object.port) + else: + raise AirflowException("No Neo4J connection: {}".format(n4j_conn_id)) + + return config + + @staticmethod + def get_driver(config): + """ + Establish a TCP connection to the server + """ + # Check if we already have a driver we can re-use before creating a new one + return GraphDatabase.driver( + uri=config['host'], + auth=config['credentials'] + ) + + @staticmethod + def get_session(driver): + """ + Get a neo4j.session from the driver. + """ + # Check if we already have a session we can re-use before creating a new one + return driver.session() + + def run_query(self, cypher_query, parameters=None): + """ + Uses a session to execute submit a query for execution + :param cypher_query: Cypher query eg. MATCH (a) RETURN (a) + :param parameters: Optional list of parameters to use with the query + :return: neo4j.BoltStatementResult see https://neo4j.com/docs/api/python-driver/current/results.html + """ + a = Neo4JHook.get_config(self._n4j_conn_id) + b = Neo4JHook.get_driver(a) + c = Neo4JHook.get_session(b) Review comment: Please use more meaningful variables' names. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
