airflow neo4j 源码

airflow neo4j 代码

文件路径：/airflow/providers/neo4j/hooks/neo4j.py

#
# 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.
"""This module allows to connect to a Neo4j database."""
from __future__ import annotations

from neo4j import GraphDatabase, Neo4jDriver, Result

from airflow.hooks.base import BaseHook
from airflow.models import Connection


class Neo4jHook(BaseHook):
    """
    Interact with Neo4j.

    Performs a connection to Neo4j and runs the query.

    :param neo4j_conn_id: Reference to :ref:`Neo4j connection id <howto/connection:neo4j>`.
    """

    conn_name_attr = 'neo4j_conn_id'
    default_conn_name = 'neo4j_default'
    conn_type = 'neo4j'
    hook_name = 'Neo4j'

    def __init__(self, conn_id: str = default_conn_name, *args, **kwargs) -> None:
        super().__init__(*args, **kwargs)
        self.neo4j_conn_id = conn_id
        self.connection = kwargs.pop("connection", None)
        self.client = None

    def get_conn(self) -> Neo4jDriver:
        """
        Function that initiates a new Neo4j connection
        with username, password and database schema.
        """
        if self.client is not None:
            return self.client

        self.connection = self.get_connection(self.neo4j_conn_id)

        uri = self.get_uri(self.connection)
        self.log.info('URI: %s', uri)

        is_encrypted = self.connection.extra_dejson.get('encrypted', False)

        self.client = GraphDatabase.driver(
            uri, auth=(self.connection.login, self.connection.password), encrypted=is_encrypted
        )

        return self.client

    def get_uri(self, conn: Connection) -> str:
        """
        Build the uri based on extras
        - Default - uses bolt scheme(bolt://)
        - neo4j_scheme - neo4j://
        - certs_self_signed - neo4j+ssc://
        - certs_trusted_ca - neo4j+s://

        :param conn: connection object.
        :return: uri
        """
        use_neo4j_scheme = conn.extra_dejson.get('neo4j_scheme', False)
        scheme = 'neo4j' if use_neo4j_scheme else 'bolt'

        # Self signed certificates
        ssc = conn.extra_dejson.get('certs_self_signed', False)

        # Only certificates signed by CA.
        trusted_ca = conn.extra_dejson.get('certs_trusted_ca', False)
        encryption_scheme = ''

        if ssc:
            encryption_scheme = '+ssc'
        elif trusted_ca:
            encryption_scheme = '+s'

        return f"{scheme}{encryption_scheme}://{conn.host}:{7687 if conn.port is None else conn.port}"

    def run(self, query) -> Result:
        """
        Function to create a neo4j session
        and execute the query in the session.

        :param query: Neo4j query
        :return: Result
        """
        driver = self.get_conn()
        if not self.connection.schema:
            with driver.session() as session:
                result = session.run(query)
                return result.data()
        else:
            with driver.session(database=self.connection.schema) as session:
                result = session.run(query)
                return result.data()

相关信息

airflow 源码目录

相关文章

airflow init 源码