tsh logout does not remove kubeconfig contexts

[aberoham]

What happened:

tsh logout does not remove live kubeconfig key & cert

What you expected to happen:

tsh logout would remove all key material

How to reproduce it (as minimally and precisely as possible):

➜  ~ rm -rf ~/.kube ~/.tsh ; tsh login --proxy=[redacted] --auth=[redacted]
If browser window does not open automatically, open it by clicking on the link:
 http://127.0.0.1:56436/[redacted]
> Profile URL:  https://[redacted]:3080
  Logged in as: [redacted]
  Roles:        admin*
  Logins:       root, [redacted]
  Valid until:  2018-09-29 11:06:12 -0400 EDT [valid for 1h0m0s]
  Extensions:   permit-agent-forwarding, permit-port-forwarding, permit-pty


* RBAC is only available in Teleport Enterprise
  https://gravitaitonal.com/teleport/docs/enteprise

➜  ~ kubectl config view
apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: REDACTED
    server: [redacted]:3026
  name: [redacted]
contexts:
- context:
    cluster: [redacted]
    user: [redacted]
  name: [redacted]
current-context: [redacted]
kind: Config
preferences: {}
users:
- name: [redacted]
  user:
    client-certificate-data: REDACTED
    client-key-data: REDACTED

➜  ~ tsh logout
Logged out all users from all proxies.

➜  ~ kubectl config view
apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: REDACTED
    server: [redacted]:3026
  name: [redacted]
contexts:
- context:
    cluster: [redacted]
    user: [redacted]
  name: [redacted]
current-context: [redacted]
kind: Config
preferences: {}
users:
- name: [redacted]
  user:
    client-certificate-data: REDACTED
    client-key-data: REDACTED

➜  ~ kubectl get nodes
NAME                            STATUS    ROLES     AGE       VERSION
[redacted]   Ready     <none>    17d       v1.10.5

➜  ~ tsh ls
error: No proxy address specified, missed --proxy flag?

➜  ~ kubectl get pods
NAME                        READY     STATUS    RESTARTS   AGE
nginx-65899c769f-c5vq5      1/1       Running   0          4d
teleport-6bd9b6c7d9-m828p   1/1       Running   0          3d

Environment:

• Tsh version (use tsh version): Teleport v3.0.0-rc.3 git:v3.0.0-rc.3-0-g5bf50d83

[kontsevoy]

@klizhentas is this just an omission, or is there a real difficulty of doing this? I actually bumped into this when doing a demo recently.