bug: kflex fails when kflex-initial-ctx-name is invalid

[francostellari]

Describe the bug

kflex create cp1 fails when the kubeconfig contains a kflex-initial-ctx-name pointing to an invalid contexts

kflex create cp1
✔ Checking for saved initial context...
✔ Switching to initial context...
Error getting client: error building kubeconfig: invalid configuration: [context was not found for specified context: kind-kubeflex, cluster has no server defined]

Steps To Reproduce

1. kflex init -c
2. kind delete clusters --all
3. oc login ....
4. helm upgrade --install kubeflex-operator chart/ --namespace kubeflex-system --set isOpenShift=true

the kubeconfig still contains something like:

preferences:
  extensions:
  - extension:
      data:
        kflex-initial-ctx-name: kind-kubeflex
      metadata:
        creationTimestamp: null
        name: kflex-config-extension-name
    name: kflex-config-extension-name

Then

kflex create cp1
✔ Checking for saved initial context...
✔ Switching to initial context...
Error getting client: error building kubeconfig: invalid configuration: [context was not found for specified context: kind-kubeflex, cluster has no server defined]

Expected Behavior

kflex should check on the validity of kflex-initial-ctx-name before using it.
If it is not valid, ignore it, assume that it was not enetered before

Additional Context

No response

[MikeSpreitzer]

I find that with KubeFlex 0.6.3, if the extension stores the name of a context that exists but is not working, this is an unrecoverable state: no kflex ctx command will fix it. For example, I set the extension to say the hosting context is "kscore-stage" at a time when that context exists but is unusable. Then:

mspreitz@mjs13 kubestellar % kubectl config use-context kind-kubeflex
Switched to context "kind-kubeflex".

mspreitz@mjs13 kubestellar % kflex ctx wds1
kubeconfig context wds1 not found (context wds1 not found), trying to load from server...
◐ Switching to context wds1...Error getting kf client: error creating NewDiscoveryRESTMapper: Get "https://c115-e.us-south.containers.cloud.ibm.com:30486/api": dial tcp 50.22.129.34:30486: connect: connection refused

mspreitz@mjs13 kubestellar % kflex ctx
✔ Checking for saved hosting cluster context...
✔ Switching to hosting cluster context...

mspreitz@mjs13 kubestellar % kubectl config current-context
kscore-stage

mspreitz@mjs13 kubestellar % yq .preferences ${KUBECONFIG:-$HOME/.kube/config}
extensions:
  - extension:
      data:
        kflex-initial-ctx-name: kscore-stage
      metadata:
        creationTimestamp: null
        name: kflex-config-extension-name
    name: kflex-config-extension-name

[MikeSpreitzer]

Note also that https://docs.kubestellar.io/release-0.24.0/direct/get-started/ does not invoke kflex init or kflex create, it only has kflex ctx commands.