Greetings guys! I want to start a discussion about deprecation cli configuration options https://airflow.apache.org/docs/apache-airflow/stable/configurations-ref.html#cli as well as `airflow/api/client` in upcoming minor/feature release of Airflow (2.9 or 2.10 depends on).
This options control how end users retrieve information from the Database, there is two kind provided classes `airflow.api.client.api_client.Client` - direct access to DB, `airflow.api.client.json_client.Client` - access through Experimental API However internal clients cover only this cli commands: - trigger_dag: airflow dags trigger - delete_dag: airflow dags delete - get_pool: airflow pool get - get_pools: airflow pool list and airflow pool export - create_pool: airflow pool set and airflow pool import - pool_delete: airflow pool delete - get_lineage: doesn't use anywhere in CLI and Airflow codebase As a result, implementation of CLI spread across different modules / subpackages and in some cases could use experimental API. Seems like it is an abandoned implementation which comes from pre Airflow 2 and we have to support it nowadays. *My proposal*: 1. Copy implementation from `airflow.api.client.local_client.Client` into the the code from appropriate modules into the airflow/cli/commands 2. Set default value for `[cli] api_client` to None. In case if values set in airflow.cfg (e.g. from the previous version of Airflow), raise future warning and update it to None if it set to `airflow.api.client.local_client.Client` in other cases do not touch 3. Set default value for `[cli] endpoint_url` to None. In case if values set in airflow.cfg raise future warning, and do not update value. 4. `airflow.api.client.get_current_api_client` should able to return None, if it return None, then it should use implementation from the airflow/cli/commands, otherwise use deprecated client, with raising RemovedInAirflow3Warning WDYT?
