Kombu version issue

[dafrenchyman]

FYI - I'm not sure if this issue was specific to just me, as I've modified this repository to install everything:

    && pip install apache-airflow[all]==$AIRFLOW_VERSION \
    && pip install airflow-plugins \

But, I ran into an issue with Kombu==4.4.0 This basically broke Celery on the worker nodes on my Kubernetes cluster. I found others that had a similar issue: cookiecutter/cookiecutter-django#1954

I ended up fixing it by running

   && pip install kombu==4.3.0 \

Before installing airflow.

[sdwa0]

I ran into the same issue too (VersionMismatch for redis-py). I think it is due to the new version of kombu too, more specifically the following change that was released on kombu v4.4.0:
celery/kombu@eb6e4c8

I fixed with a similar change like @dafrenchyman did.
&& pip install 'kombu>=4.2.0,<4.4.0' \