Kube API server connection indicator on UI

[christophenne]

Is your feature request related to a problem? Please describe.
While using the UI, the connection to the API server (especially in the watch loops) could be lost. I had this issue recently when using glasskube in my OVH cluster, and then running a security patch of the kubernetes cluster, where the watch loop seems to have been disturbed at least:

W0423 13:21:29.949641   75118 reflector.go:462] pkg/mod/k8s.io/client-go@v0.29.4/tools/cache/reflector.go:229: watch of *v1alpha1.Package ended with: Internal error occurred: rpc error: code = Unknown desc = context canceled
W0423 13:30:29.677213   75118 reflector.go:462] pkg/mod/k8s.io/client-go@v0.29.4/tools/cache/reflector.go:229: watch of *v1alpha1.Package ended with: an error on the server ("unable to decode an event from the watch stream: http2: client connection lost") has prevented the request from succeeding
W0423 13:30:29.677265   75118 reflector.go:462] pkg/mod/k8s.io/client-go@v0.29.4/tools/cache/reflector.go:229: watch of *v1alpha1.PackageInfo ended with: an error on the server ("unable to decode an event from the watch stream: http2: client connection lost") has prevented the request from succeeding

Interestingly, it seems that afterwards the connection has come back up automatically. Either way, we should investigate this (maybe there are also other cases where the watch loop is cancelled / terminated) and find a way to show this information and how to resolve it to the user on the UI, e.g. "It seems that your Kubernets API server is not reachable – please check again and restart with glasskube server".

Describe alternatives you've considered

Additional context