Compatibility issue between K8s v1.9 and python client v5.0

[huang195]

I used kubeadm to install a k8s cluster:

root@haih2:~# kubectl version
Client Version: version.Info{Major:"1", Minor:"9", GitVersion:"v1.9.3", GitCommit:"d2835416544f298c919e2ead3be3d0864b52323b", GitTreeState:"clean", BuildDate:"2018-02-07T12:22:21Z", GoVersion:"go1.9.2", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"9", GitVersion:"v1.9.3", GitCommit:"d2835416544f298c919e2ead3be3d0864b52323b", GitTreeState:"clean", BuildDate:"2018-02-07T11:55:20Z", GoVersion:"go1.9.2", Compiler:"gc", Platform:"linux/amd64"}

I used pip to install kubernetes python client version 5.0.

root@haih2:~# pip show kubernetes
---
Metadata-Version: 2.0
Name: kubernetes
Version: 5.0.0
Summary: Kubernetes python client
Home-page: https://github.com/kubernetes-client/python
Author: Kubernetes
Author-email: UNKNOWN
Installer: pip
License: Apache License Version 2.0
Location: /usr/local/lib/python2.7/dist-packages
Requires: ipaddress, six, requests-oauthlib, pyyaml, python-dateutil, certifi, websocket-client, google-auth, setuptools, urllib3, requests
Classifiers:
  Development Status :: 5 - Production/Stable
  Topic :: Utilities
  Intended Audience :: Developers
  Intended Audience :: Information Technology
  License :: OSI Approved :: Apache Software License
  Operating System :: OS Independent
  Programming Language :: Python
  Programming Language :: Python :: 2
  Programming Language :: Python :: 2.7
  Programming Language :: Python :: 3
  Programming Language :: Python :: 3.4
  Programming Language :: Python :: 3.5
  Programming Language :: Python :: 3.6

Per README, K8s python client v5.0 is compatible with K8s v1.9, but a simple program like the following doesn't work:

from kubernetes import client, config, watch
import sys

config.load_kube_config(config_file='./config')
a = client.CoreV1Api()
w = watch.Watch()
for event in w.stream(a.list_event_for_all_namespaces, resource_version=1):
    print (event)

The error message I got is:

Traceback (most recent call last):
  File "test.py", line 8, in <module>
    for event in w.stream(a.list_event_for_all_namespaces, resource_version=1):
  File "/usr/local/lib/python2.7/dist-packages/kubernetes/watch/watch.py", line 127, in stream
    yield self.unmarshal_event(line, return_type)
  File "/usr/local/lib/python2.7/dist-packages/kubernetes/watch/watch.py", line 86, in unmarshal_event
    js['object'] = self._api_client.deserialize(obj, return_type)
  File "/usr/local/lib/python2.7/dist-packages/kubernetes/client/api_client.py", line 239, in deserialize
    return self.__deserialize(data, response_type)
  File "/usr/local/lib/python2.7/dist-packages/kubernetes/client/api_client.py", line 279, in __deserialize
    return self.__deserialize_model(data, klass)
  File "/usr/local/lib/python2.7/dist-packages/kubernetes/client/api_client.py", line 625, in __deserialize_model
    instance = klass(**kwargs)
  File "/usr/local/lib/python2.7/dist-packages/kubernetes/client/models/v1_event.py", line 107, in __init__
    self.involved_object = involved_object
  File "/usr/local/lib/python2.7/dist-packages/kubernetes/client/models/v1_event.py", line 266, in involved_object
    raise ValueError("Invalid value for `involved_object`, must not be `None`")
ValueError: Invalid value for `involved_object`, must not be `None`

[howardshaw]

I encount the same issue with you in k8s 1.9.3.

>>> for event in w.stream(a.list_event_for_all_namespaces, resource_version=1):
...   print (event)
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.6/site-packages/kubernetes/watch/watch.py", line 125, in stream
    yield self.unmarshal_event(line, return_type)
  File "/usr/lib/python3.6/site-packages/kubernetes/watch/watch.py", line 84, in unmarshal_event
    js['object'] = self._api_client.deserialize(obj, return_type)
  File "/usr/lib/python3.6/site-packages/kubernetes/client/api_client.py", line 236, in deserialize
    return self.__deserialize(data, response_type)
  File "/usr/lib/python3.6/site-packages/kubernetes/client/api_client.py", line 276, in __deserialize
    return self.__deserialize_model(data, klass)
  File "/usr/lib/python3.6/site-packages/kubernetes/client/api_client.py", line 622, in __deserialize_model
    instance = klass(**kwargs)
  File "/usr/lib/python3.6/site-packages/kubernetes/client/models/v1_event.py", line 107, in __init__
    self.involved_object = involved_object
  File "/usr/lib/python3.6/site-packages/kubernetes/client/models/v1_event.py", line 266, in involved_object
    raise ValueError("Invalid value for `involved_object`, must not be `None`")
ValueError: Invalid value for `involved_object`, must not be `None

pip info as below

# pip3 show kubernetes
Name: kubernetes
Version: 5.0.0
Summary: Kubernetes python client
Home-page: https://github.com/kubernetes-client/python
Author: Kubernetes
Author-email: UNKNOWN
License: Apache License Version 2.0
Location: /usr/lib/python3.6/site-packages
Requires: google-auth, python-dateutil, certifi, ipaddress, setuptools, websocket-client, urllib3, requests-oauthlib, six, requests, pyyaml

[roycaihw]

The problem is that API server returns 410 when the resource version is too old (resource_version=1):

{"type":"ERROR","object":{"kind":"Status","apiVersion":"v1","metadata":{},"status":"Failure","message":"The resourceVersion for the provided watch is too old.","reason":"Expired","code":410}}

And the python client code tries to validate the error object as an event object, and reports a validation error. I would suggest that when API server responds with an error, we should raise it before parsing it into a regular API object.

If you modify the parameter to be resource_version=0 (return what we currently have in cache) or remove the parameter (defaults to changes from the beginning of history) it will work.