Starting Airflow webserver fails with sqlalchemy.exc.NoInspectionAvailable: No inspection system is available

Question

Installation done properly. db initiated properly and trying to start the webserver shows the following error.

I reinstalled everything but its still not working.

I will appreciate if anyone help me.

Console output:

$:~/airflow# airflow webserver -p 8080
  ____________       _____________
 ____    |__( )_________  __/__  /________      __
____  /| |_  /__  ___/_  /_ __  /_  __ \_ | /| / /
___  ___ |  / _  /   _  __/ _  / / /_/ /_ |/ |/ /
 _/_/  |_/_/  /_/    /_/    /_/  \____/____/|__/
[2020-04-08 13:14:20,573] {__init__.py:51} INFO - Using executor SequentialExecutor
[2020-04-08 13:14:20,574] {dagbag.py:403} INFO - Filling up the DagBag from /home/cato_service/airflow/dags
Traceback (most recent call last):
  File "/usr/local/bin/airflow", line 37, in <module>
    args.func(args)
  File "/usr/local/lib/python3.6/dist-packages/airflow/utils/cli.py", line 75, in wrapper
    return f(*args, **kwargs)
  File "/usr/local/lib/python3.6/dist-packages/airflow/bin/cli.py", line 900, in webserver
    app = cached_app_rbac(None) if settings.RBAC else cached_app(None)
  File "/usr/local/lib/python3.6/dist-packages/airflow/www/app.py", line 233, in cached_app
    app = create_app(config, testing)
  File "/usr/local/lib/python3.6/dist-packages/airflow/www/app.py", line 103, in create_app
    models.Chart, Session, name="Charts", category="Data Profiling"))
  File "/usr/local/lib/python3.6/dist-packages/flask_admin/contrib/sqla/view.py", line 330, in __init__
    menu_icon_value=menu_icon_value)
  File "/usr/local/lib/python3.6/dist-packages/flask_admin/model/base.py", line 818, in __init__
    self._refresh_cache()
  File "/usr/local/lib/python3.6/dist-packages/flask_admin/model/base.py", line 913, in _refresh_cache
    self._search_supported = self.init_search()
  File "/usr/local/lib/python3.6/dist-packages/flask_admin/contrib/sqla/view.py", line 581, in init_search
    if tools.is_hybrid_property(self.model, name):
  File "/usr/local/lib/python3.6/dist-packages/flask_admin/contrib/sqla/tools.py", line 209, in is_hybrid_property
    return last_name in get_hybrid_properties(last_model)
  File "/usr/local/lib/python3.6/dist-packages/flask_admin/contrib/sqla/tools.py", line 190, in get_hybrid_properties
    for key, prop in inspect(model).all_orm_descriptors.items()
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/inspection.py", line 72, in inspect
    "available for object of type %s" % type_
sqlalchemy.exc.NoInspectionAvailable: No inspection system is available for object of type <class 'method'>

Answer 1

Just hit this myself. its an issue with SQLAlchemy dependency

to fix I did the following:

pip3 uninstall SQLAlchemy
pip3 install SQLAlchemy==1.3.15

https://github.com/apache/airflow/issues/8211

Answer 2

Including the instruction pip install SQLAlchemy==1.3.15 in the Dockerfile and rebuilding the image has solved the issue. Thanks a lot @Java Guy!

Answer 3

I faced the above issue. I added below line in Dockerfile

&& pip install SQLAlchemy==1.3.15 \

Build the docker image as

docker build --rm -t <tag> .

Run :

docker run -d -p 8080:8080 <tag>