Merge pull request #102544 from jeremyje/fixnpd

GCE Windows: Only create NPD kubeconfig when the file path is defined.

cluster/gce/windows/k8s-node-setup.psm1

@@ -1719,7 +1719,7 @@ function DownloadAndInstall-NodeProblemDetector {
 }
 
 # Creates the node-problem-detector user kubeconfig file at
-# $env:NODEPROBLEMDETECTOR_KUBECONFIG_FILE.
+# $env:NODEPROBLEMDETECTOR_KUBECONFIG_FILE (if defined).
 #
 # Create-NodePki() must be called first.
 #
@@ -1727,10 +1727,12 @@ function DownloadAndInstall-NodeProblemDetector {
 #   CA_CERT
 #   NODE_PROBLEM_DETECTOR_TOKEN
 function Create-NodeProblemDetectorKubeConfig {
+  if (-not [string]::IsNullOrEmpty(${env:NODEPROBLEMDETECTOR_KUBECONFIG_FILE})) {
     Create-Kubeconfig -Name 'node-problem-detector' `
       -Path ${env:NODEPROBLEMDETECTOR_KUBECONFIG_FILE} `
       -Token ${kube_env}['NODE_PROBLEM_DETECTOR_TOKEN']
   }
+}
 
 # Configures NPD to run with the bundled monitor configs and report against the Kubernetes api server.
 function Configure-NodeProblemDetector {