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Re: [External] Dynamic tasks in a dag?


This isn't needed as the tasks are added to the dag when specified, so they DAG object keeps track of the tasks.

-ash 

> On 14 Sep 2018, at 18:30, Alex Tronchin-James 949-412-7220 <alex.n.james@xxxxxxxxx> wrote:
> 
> Don't you need to preserve the task objects? Your implementation overwrites
> each by the successor, so only the last task would be kept, despite your
> print statements. Try building a list or dict of tasks like:
> 
> tasks =[] #only at the top
> for file in glob('dags/snowsql/create/udf/*.sql'):
> print("FILE {}".format(file))
> tasks.append(
> create_snowflake_operator(file, dag, 'snowflake_default')
> )
> tasks[-1].set_upstream(start)
> 
> On Fri, Sep 14, 2018 at 17:20 Frank Maritato
> <fmaritato@xxxxxxxxxxxxx.invalid> wrote:
> 
>> Ok, my mistake. I thought that command was querying the server for its
>> information and not just looking in a directory relative to where it is
>> being run. I have it working now. Thanks Chris and Sai!
>> 
>> 
>> On 9/14/18, 9:58 AM, "Chris Palmer" <chris@xxxxxxxxxxxx> wrote:
>> 
>>    The relative paths might work from where ever you are evoking 'airflow
>>    list_tasks', but that doesn't mean they work from wherever the
>> webserver is
>>    parsing the dags from.
>> 
>>    Does running 'airflow list_tasks' from some other running directory
>> work?
>> 
>>    On Fri, Sep 14, 2018 at 12:35 PM Frank Maritato
>>    <fmaritato@xxxxxxxxxxxxx.invalid> wrote:
>> 
>>> Do you mean give the full path to the files? The relative path I'm
>> using
>>> definitely works. When I type airflow list_dags, I can see the
>> output from
>>> the print statements that the glob is finding my sql files and
>> creating the
>>> snowflake operators.
>>> 
>>> airflow list_tasks workflow also lists all the operators I'm
>> creating. I'm
>>> just not seeing them in the ui.
>>> 
>>> On 9/14/18, 9:10 AM, "Sai Phanindhra" <phani8996@xxxxxxxxx> wrote:
>>> 
>>>    Hi frank,
>>>    Can you try giving global paths?
>>> 
>>>    On Fri 14 Sep, 2018, 21:35 Frank Maritato, <
>> fmaritato@xxxxxxxxxxxxx
>>> .invalid>
>>>    wrote:
>>> 
>>>> Hi,
>>>> 
>>>> I'm using apache airflow 1.10.0 and I'm trying to dynamically
>>> generate
>>>> some tasks in my dag based on files that are in the dags
>> directory.
>>> The
>>>> problem is, I don't see these tasks in the ui, I just see the
>>> 'start' dummy
>>>> operator. If I type 'airflow list_tasks workflow', they are
>> listed.
>>>> Thoughts?
>>>> 
>>>> Here is how I'm generating the tasks:
>>>> 
>>>> 
>>>> def create_snowflake_operator(file, dag, snowflake_connection):
>>>>    file_repl = file.replace('/', '_')
>>>>    file_repl = file_repl.replace('.sql', '')
>>>>    print("TASK_ID {}".format(file_repl))
>>>>    return SnowflakeOperator(
>>>>        dag=dag,
>>>>        task_id='create_{}'.format(file_repl),
>>>>        snowflake_conn_id=snowflake_connection,
>>>>        sql=file
>>>>    )
>>>> 
>>>> DAG_NAME = 'create_objects'
>>>> dag = DAG(
>>>>    DAG_NAME,
>>>>    default_args=args,
>>>>    dagrun_timeout=timedelta(hours=2),
>>>>    schedule_interval=None,
>>>> )
>>>> 
>>>> start = DummyOperator(
>>>>    dag=dag,
>>>>    task_id="start",
>>>> )
>>>> 
>>>> print("creating snowflake operators")
>>>> 
>>>> for file in glob('dags/snowsql/create/udf/*.sql'):
>>>>    print("FILE {}".format(file))
>>>>    task = create_snowflake_operator(file, dag,
>> 'snowflake_default')
>>>>    task.set_upstream(start)
>>>> 
>>>> for file in glob('dags/snowsql/create/table/*.sql'):
>>>>    print("FILE {}".format(file))
>>>>    task = create_snowflake_operator(file, dag,
>> 'snowflake_default')
>>>>    task.set_upstream(start)
>>>> 
>>>> for file in glob('dags/snowsql/create/view/*.sql'):
>>>>    print("FILE {}".format(file))
>>>>    task = create_snowflake_operator(file, dag,
>> 'snowflake_default')
>>>>    task.set_upstream(start)
>>>> 
>>>> print("done {}".format(start.downstream_task_ids))
>>>> 
>>>> Thanks in advance
>>>> --
>>>> Frank Maritato
>>>> 
>>> 
>>> 
>>> 
>> 
>> 
>>