[GitHub] [airflow] josh-fell commented on issue #17022: TaskInstance.previous_execution_date_success fails with: 'TaskInstance' object has no attribute 'task'

[GitBox <gi...@apache.org>]

josh-fell commented on issue #17022:
URL: https://github.com/apache/airflow/issues/17022#issuecomment-887959994


   FWIW this is also reproducible in Airflow 2.
   
   **Airflow version**
   2.1.0
   
   Using the DAG below, the `get_previous_execution_date()` call from `TaskInstance` object directly succeeds while the same method call accessing the `TaskInstance` from the `DagRun` object fails for the same exception noted originally.
   
   ```python
   from airflow import DAG
   from airflow.operators.python import PythonOperator
   from airflow.utils.dates import days_ago
   
   dag = DAG("mwe", start_date=days_ago(14))
   
   def some_function(dag_run, ti):
       from airflow.utils.state import State
   
       dag_run_tis = dag_run.get_task_instances()
       print(ti.get_previous_execution_date(state=State.SUCCESS))
       print(dag_run_tis[0].get_previous_execution_date(state=State.SUCCESS))
   
   with dag:
       op = PythonOperator(task_id="op_some_function", python_callable=some_function)
   ```
   
   It appears as though the the `TaskInstance` objects return different sets of attributes when accessing them directly via the "ti" context or the "dag_run" context and indeed, there is no `task` attribute in the `TaskInstance` returned via `DagRun`.
   
   Get Previous Execution Date from TaskInstance | Get Previous Execution Date via DagRun |
   ----------------------------------------------- | ----------------------------------------- |
   `ti.get_previous_execution_date()` | `dag_run.get_task_instances()[0].get_previous_execution_date()` |
   _log | _sa_instance_state |
   _sa_instance_state | _try_number |
   _try_number | dag_id |
   dag_id | duration |
   duration | end_date |
   end_date | execution_date |
   execution_date | executor_config |
   executor_config | external_executor_id |
   hostname | hostname |
   job_id | job_id |
   max_tries | max_tries |
   operator | operator |
   pid | pid |
   pool | pool |
   pool_slots | pool_slots |
   priority_weight | priority_weight |
   queue | queue |
   queued_dttm | queued_by_job_id |
   raw | queued_dttm |
   run_as_user | start_date |
   start_date | state |
   state | task_id |
   task | test_mode |
   task_id | unixname |
   test_mode |
   unixname |
   
   @tsabsch Have you tried directly accessing the `TaskInstance` rather than going through `DagRun` as a workaround?


-- 
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.

To unsubscribe, e-mail: commits-unsubscribe@airflow.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org