kubernetes: kubectl --request-timeout (or any other client configuration flag) prevents use of in-cluster configuration

What happened: When running a pod within the cluster, using the --request-timeout option always fails instantly

What you expected to happen: It should respect --request-timeout (or, at a minimum, give a better error message). The real issue is that one can not make sure that kubectl will timeout.

We expect to need to timeout under adverse conditions but kubectl in-cluster never times out and thus we have to do process-level timeouts and kill operations.

How to reproduce it (as minimally and precisely as possible): Create a trivial container that can run kubectl and give the pod a service role to access “kubectl get pods” (for the example below). It does not matter if you give full access or limited access roles - the --request-timeout option always causes kubectl to fail when run within the cluster.

Anything else we need to know?:

Environment:

• Kubernetes version (use kubectl version): Client Version: version.Info{Major:“1”, Minor:“18”, GitVersion:“v1.18.4”, GitCommit:“c96aede7b5205121079932896c4ad89bb93260af”, GitTreeState:“clean”, BuildDate:“2020-06-17T15:57:19Z”, GoVersion:“go1.13.6”, Compiler:“gc”, Platform:“linux/amd64”} Server Version: version.Info{Major:“1”, Minor:“18”, GitVersion:“v1.18.4”, GitCommit:“c96aede7b5205121079932896c4ad89bb93260af”, GitTreeState:“clean”, BuildDate:“2020-06-17T15:57:19Z”, GoVersion:“go1.13.6”, Compiler:“gc”, Platform:“linux/amd64”}

• Cloud provider or hardware configuration: Azure

• OS (e.g: cat /etc/os-release): ubuntu 18.04.4 LTS

• Kernel (e.g. uname -a): Linux k8s-master-18861755-2 5.3.0-1031-azure #32~18.04.1-Ubuntu SMP Mon Jun 22 15:27:23 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

• Install tools: aks-engine 0.53.0

• Network plugin and version (if this is a network-related bug): Azure CNI

• Others:

In a cluster, on a pod, I can issue kubectl get pods without trouble but if it includes --request-timeout it instantly fails:

# kubectl version
Client Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.4", GitCommit:"c96aede7b5205121079932896c4ad89bb93260af", GitTreeState:"clean", BuildDate:"2020-06-17T15:57:19Z", GoVersion:"go1.13.6", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.4", GitCommit:"c96aede7b5205121079932896c4ad89bb93260af", GitTreeState:"clean", BuildDate:"2020-06-17T15:57:19Z", GoVersion:"go1.13.6", Compiler:"gc", Platform:"linux/amd64"}
# kubectl get pods --request-timeout 30
The connection to the server localhost:8080 was refused - did you specify the right host or port?
# kubectl get pods
NAME                                                              READY   STATUS      RESTARTS   AGE
acr-transformer-6f497d647c-5rx7d                                  1/1     Running     0          18m
acr-transformer-6f497d647c-d9j2s                                  1/1     Running     0          18m
. . . .