[Release-1.31] - The "Standalone"-mode of oidc-login in the wrapped kubectl library fails, with: no Auth Provider found for name "oidc"

[brandond]

Backport fix for The "Standalone"-mode of oidc-login in the wrapped kubectl library fails, with: no Auth Provider found for name "oidc"

• The "Standalone"-mode of oidc-login in the wrapped kubectl library fails, with: no Auth Provider found for name "oidc" #11268

[mdrahman-suse]

Validated on release-1.31 with commit 53d4dd8

NOTE: No real OIDC provider has been used

Environment, Cluster config

Ubuntu 24.04
Single server

Testing steps:

• Install k3s
• Ensure cluster is up
• Append /etc/rancher/k3s/k3s.yaml (Default kubeconfig location) with below under users:

- name: keycloak
  user:
    auth-provider:
      config:
        client-id: YOUR_CLIENT_ID
        client-secret: YOUR_CLIENT_SECRET
        idp-issuer-url: https://issuer.example.com
      name: oidc

• Update user under context in /etc/rancher/k3s/k3s.yaml with below:

- context:
    cluster: default
    user: keycloak
...

• Run kubectl auth whoami
• Ensure the error below is NOT observed

error: no Auth Provider found for name "oidc"

Replication

$ k3s -v
k3s version v1.31.2+k3s1 (6da20424)
go version go1.22.8

## Update kubeconfig file
$ sudo vi /etc/rancher/k3s/k3s.yaml

## Error is observed
$ kubectl auth whoami
error: no Auth Provider found for name "oidc"

Validation

$ k3s -v
k3s version v1.31.2+k3s-53d4dd85 (53d4dd85)
go version go1.22.8

## Update kubeconfig
$ sudo vi /etc/rancher/k3s/k3s.yaml

## Error is NOT observed, this is expected with dummy auth provider 
$ kubectl auth whoami
Unable to connect to the server: No valid id-token, and cannot refresh without refresh-token