beibootctl crashes when invalid kubeconfig is set

[tschale]

I deleted a cluster/context/user from my kubeconfig, but still had it as the current context. beibootctl version yielded following output:

Traceback (most recent call last):
  File "cli.__main__", line 29, in cli
  File "kubernetes.config.kube_config", line 813, in load_kube_config
  File "kubernetes.config.kube_config", line 773, in _get_kube_config_loader
  File "kubernetes.config.kube_config", line 206, in __init__
  File "kubernetes.config.kube_config", line 259, in set_active_context
  File "kubernetes.config.kube_config", line 660, in get_with_name
kubernetes.config.config_exception.ConfigException: Invalid kube-config file. Expected object with name deleted-cluster in /home/gutschi/.kube/config/contexts list

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "cli.__main__", line 67, in main
  File "click.core", line 1130, in __call__
  File "click.core", line 1055, in main
  File "click.core", line 1654, in invoke
  File "click.core", line 1404, in invoke
  File "click.core", line 760, in invoke
  File "click.decorators", line 26, in new_func
  File "cli.__main__", line 31, in cli
RuntimeError: Could not load KUBECONFIG: Invalid kube-config file. Expected object with name deleted-cluster in /home/gutschi/.kube/config/contexts list

It's certainly not a big deal, however I'm a little bit surprised that beibootctl needs a valid kubeconfig to print out its version.

[tschale]

This comes from the method cli in cli.__main__.py, which serves as a base for the other commands. As most of the other commands need a kubeconfig, this currently stays at it is. We might think about not raising the complete stacktrace though. In my opinion that seems like something broke and not like an expected error.