Question

我们正在使用Apache 1.9.0。我写了一个雪花钩插件。我已将钩子放在$ AIRFLOW_HOME / plugins目录中。

$AIRFLOW_HOME
  +--plugins
    +--snowflake_hook2.py

snowflake_hook2.py

# This is the base class for a plugin
from airflow.plugins_manager import AirflowPlugin

# This is necessary to expose the plugin in the Web interface
from flask import Blueprint
from flask_admin import BaseView, expose
from flask_admin.base import MenuLink

# This is the base hook for connecting to a database
from airflow.hooks.dbapi_hook import DbApiHook

# This is the snowflake provided Connector
import snowflake.connector

# This is the default python logging package
import logging

class SnowflakeHook2(DbApiHook):
    """
    Airflow Hook to communicate with Snowflake
    This is implemented as a Plugin
    """
    def __init__(self, connname_in='snowflake_default', db_in='default', wh_in='default', schema_in='default'):
        logging.info('# Connecting to {0}'.format(connname_in))
        self.conn_name_attr = 'snowflake_conn_id'
        self.connname = connname_in
        self.superconn = super().get_connection(self.connname) #gets the values from Airflow

        {SNIP - Connection stuff that works}
        self.cur = self.conn.cursor()

    def query(self,q,params=None):
        """From jmoney's db_wrapper allows return of a full list of rows(tuples)"""
        if params == None: #no Params, so no insertion
            self.cur.execute(q)
        else: #make the parameter substitution
            self.cur.execute(q,params)
        self.results = self.cur.fetchall()
        self.rowcount = self.cur.rowcount
        self.columnnames = [colspec[0] for colspec in self.cur.description]
        return self.results
    {SNIP - Other class functions}

class SnowflakePluginClass(AirflowPlugin):
    name = "SnowflakePluginModule"
    hooks = [SnowflakeHook2]
    operators = []

所以我继续在Airflows plugin_manager中添加一些打印语句，以便更好地处理正在发生的事情。重新启动网络服务器并运行气流list_dags后，这些行显示“新模块名称”（并且没有错误

SnowflakePluginModule [<class '__home__ubuntu__airflow__plugins_snowflake_hook2.SnowflakeHook2'>]
hook_module -  airflow.hooks.snowflakepluginmodule
INTEGRATING airflow.hooks.snowflakepluginmodule
snowflakepluginmodule <module 'airflow.hooks.snowflakepluginmodule'>

由于这与文档所说的一致，我应该在我的DAG中使用它：

from airflow import DAG
from airflow.hooks.snowflakepluginmodule import SnowflakeHook2 
from airflow.operators.python_operator import PythonOperator

但网络会抛出此错误

Broken DAG: [/home/ubuntu/airflow/dags/test_sf2.py] No module named 'airflow.hooks.snowflakepluginmodule'

所以问题是，我做错了什么？或者我发现了一个错误？

Answer 1

您需要按以下方式导入：

from airflow import DAG
from airflow.hooks import SnowflakeHook2 
from airflow.operators.python_operator import PythonOperator

OR

from airflow import DAG
from airflow.hooks.SnowflakePluginModule import SnowflakeHook2 
from airflow.operators.python_operator import PythonOperator

Answer 2

我认为气流不会自动通过插件目录中的文件夹并运行其下的所有内容。我成功设置它的方法是在plugins目录下有一个__init__.py，其中包含每个插件类。看看Github中的Astronomer插件，它为如何设置插件提供了一些很好的例子。

特别要看一下他们如何设置mysql插件

https://github.com/airflow-plugins/mysql_plugin

也有人在其中一个更高版本的气流中加入了一个雪花钩，你可能想要利用它：

https://github.com/apache/incubator-airflow/blob/master/airflow/contrib/hooks/snowflake_hook.py

气流插件没有正确拾取

2 个答案: