kopf is incompatible with aiohttp 4.x

[kopf-archiver]

An issue by pshchelo at 2019-11-20 09:29:33+00:00
Original URL: zalando-incubator/kopf#246
 

No urgency, consider it as an early warning.

Installing kopf and dependencies with pip install --pre

Expected Behavior

kopf-based controller starts

Actual Behavior

kopf-based controller crashes

Traceback (most recent call last):                                                                                                                                                                                   
  File "/home/ubuntu/kopf-debug/.tox/resume-master/bin/kopf", line 5, in <module>                                                                                                                                    
    from kopf.cli import main                                                                                                                                                                                        
  File "/home/ubuntu/kopf-debug/.tox/resume-master/lib/python3.7/site-packages/kopf/__init__.py", line 9, in <module>                                                                                                
    from kopf import (                                                                                                                                                                                               
  File "/home/ubuntu/kopf-debug/.tox/resume-master/lib/python3.7/site-packages/kopf/on.py", line 18, in <module>                                                                                                     
    from kopf.reactor import handling                                                                                                                                                                                
  File "/home/ubuntu/kopf-debug/.tox/resume-master/lib/python3.7/site-packages/kopf/reactor/handling.py", line 23, in <module>                                                                                       
    from kopf.clients import patching                                                                                                                                                                                
  File "/home/ubuntu/kopf-debug/.tox/resume-master/lib/python3.7/site-packages/kopf/clients/patching.py", line 5, in <module>                                                                                        
    from kopf.clients import auth                                                                                                                                                                                    
  File "/home/ubuntu/kopf-debug/.tox/resume-master/lib/python3.7/site-packages/kopf/clients/auth.py", line 75, in <module>                                                                                           
    class APISession(aiohttp.ClientSession):                                                                                                                                                                         
  File "/home/ubuntu/kopf-debug/.tox/resume-master/lib/python3.7/site-packages/aiohttp/client.py", line 266, in __init_subclass__                                                                                    
    "is forbidden".format(cls.__name__))                                                                                                                                                                             
TypeError: Inheritance class APISession from ClientSession is forbidden                    

Steps to Reproduce the Problem

1. pip install --pre kopf
2. run any controller based on kopf

Specifications

• Platform: Ubuntu 18.04
• Kubernetes version: 1.14
• Python version: 3.7
• Python packages installed: relevant ones are aiohttp==4.0.0a1, kopf==0.23rc5

Reason

aiohttp 4.x will forbid inheritance from ClientSession class, possibly due to turning it into slots-based class (for performance reasons?)
aio-libs/aiohttp@df77ea7