kube_config.py is unable to merge configs when one of configs has removed all contexts

[matihost]

  File \"/home/myuser/.local/lib/python3.6/site-packages/kubernetes/config/kube_config.py\", line 664, in load_kube_config
    persist_config=persist_config)
  File \"/home/myuser/.local/lib/python3.6/site-packages/kubernetes/config/kube_config.py\", line 620, in _get_kube_config_loader_for_yaml_file
    kcfg = KubeConfigMerger(filename)
  File \"/home/myuser/.local/lib/python3.6/site-packages/kubernetes/config/kube_config.py\", line 574, in __init__
    self.load_config(path)
  File \"/home/myuser/.local/lib/python3.6/site-packages/kubernetes/config/kube_config.py\", line 592, in load_config
    self._merge(item, config.get(item, {}), path)
  File \"/home/myuser/.local/lib/python3.6/site-packages/kubernetes/config/kube_config.py\", line 597, in _merge
    for new_item in add_cfg:
TypeError: 'NoneType' object is not iterable

when:

KUBECONFIG=/home/myuser/.kube/config:/home/myuser/.kube/microk8s.config

and for example one of them defines null contexts:

contexts: null

It happens when

kubectl config delete-context microk8s 

is invoked and there is no context left in kube config file.

Fix proposal add if:

    def _merge(self, item, add_cfg, path):
        if add_cfg is not None:
          for new_item in add_cfg:

around

python-base/config/kube_config.py

Line 596 in a2d1024

for new_item in add_cfg:

[roycaihw]

/assign @palnabarun

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[weininghu1012]

Hi, I also encounter this issue with error like:

  File "/Users/weininghu/.pyenv/virtualenvs/kafka-topic-manager/3.7.8/lib/python3.7/site-packages/kubernetes/config/kube_config.py", line 672, in _merge
    for new_item in add_cfg:
TypeError: 'NoneType' object is not iterable

Is this issue being working on?

[mohammedi-haroune]

I'm also getting this error

    def _merge(self, item, add_cfg, path):
>       for new_item in add_cfg:
E       TypeError: 'NoneType' object is not iterable

../../venv/lib/python3.7/site-packages/kubernetes/config/kube_config.py:672: TypeError