KubernetesClientConfiguration.IsInCluster() not working when automountServiceAccountToken=false

[zhiweiv]

In KubernetesClientConfiguration.IsInCluster, it uses service account token file as one check condition.

 var tokenPath = Path.Combine(ServiceAccountPath, ServiceAccountTokenKeyFileName);
 if (!FileSystem.Current.Exists(tokenPath))
 {
     return false;
 }

When set automountServiceAccountToken false(https://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/#opt-out-of-api-credential-automounting), there is no token file injected to container, KubernetesClientConfiguration.IsInCluster doesn't work correctly.

[tg123]

any alternative way to know if the app is running inside k8s?
this is designed to use incluster auth

[zhiweiv]

In client-go, seems there is no public IsInCluster method, it suggests checking return value of InClusterConfig(https://github.com/kubernetes/client-go/blob/master/examples/in-cluster-client-configuration/main.go#L42).

We used IsInCluster beyond auth purpose, plan to remove them.

[tg123]

i believe the ask is
reband IsInCluster -> HasInClusterToken ?

[brendandburns]

I don't think that IsInCluster is intended to test whether or not the container is running inside a cluster. We could make that name change to make it more clear, but honestly I'm not sure if it's worth it.