Error message for missing Kubeconfig and Non-existent context

[rashedkvm]

Signed-off-by: Rashed Kamal krashed@vmware.com

Pull request

What this PR does / why we need it

This PR fixes the UX error message when kubeconfig is missing or the current context is no longer valid.

Which issue(s) this PR fixes

Fixes #53

Describe testing done for PR

• Unit test
• Local test

Missing Kubeconfig

➜  ~  tanzu apps workload list -n workspace
Error: Unable to connect: no configuration has been found. If a kubeconfig is not set, it can be provided with the --kubeconfig flag or KUBECONFIG environment variable.
Error: exit status 2

✖  exit status 2

Missing Kubeconfig Verbose

➜  ~  tanzu apps workload list -n workspace -v 2
Error: Unable to connect: no configuration has been found. If a kubeconfig is not set, it can be provided with the --kubeconfig flag or KUBECONFIG environment variable.
API Error name:tanzu apps  error:invalid configuration: no configuration has been provided, try setting KUBERNETES_MASTER environment variable
Error: exit status 2

✖  exit status 2

Invalid Context in Kubeconfig

➜  ~  tanzu apps workload list -n workspace
Error: Unable to connect: connection refused. Confirm kubeconfig details and try again.
Error: exit status 2

✖  exit status 2

Invalid Context in Kubeconfig Verbose

➜  ~  tanzu apps workload list -n workspace -v 2
API Request name:tanzu apps  host:https://xx.xx.xx.xxx  action:List
Error: Unable to connect: connection refused. Confirm kubeconfig details and try again.
API Error name:tanzu apps  error:Get "https://xx.xx.xx.xxx/api?timeout=32s": dial tcp xx.xx.xx.xxx:443: i/o timeout
Error: exit status 2

✖  exit status 2

Additional information or special notes for your reviewer