KubeEnv var to enable Hyper-V in Windows

cluster/gce/config-default.sh

@@ -560,6 +560,10 @@ export WINDOWS_ENABLE_DSR="${WINDOWS_ENABLE_DSR:-false}"
 export WINDOWS_ENABLE_NODE_PROBLEM_DETECTOR="${WINDOWS_ENABLE_NODE_PROBLEM_DETECTOR:-none}"
 export WINDOWS_NODE_PROBLEM_DETECTOR_CUSTOM_FLAGS="${WINDOWS_NODE_PROBLEM_DETECTOR_CUSTOM_FLAGS:-}"
 
+# Enable Windows Hyper-V
+# sig-storage uses it to create Virtual Hard Disks in tests
+export WINDOWS_ENABLE_HYPERV="${WINDOWS_ENABLE_HYPERV:-false}"
+
 # TLS_CIPHER_SUITES defines cipher suites allowed to be used by kube-apiserver.
 # If this variable is unset or empty, kube-apiserver will allow its default set of cipher suites.
 export TLS_CIPHER_SUITES=""

cluster/gce/util.sh

@@ -1602,6 +1602,7 @@ BOOTSTRAP_KUBECONFIG_FILE: $(yaml-quote "${WINDOWS_BOOTSTRAP_KUBECONFIG_FILE}")
 KUBEPROXY_KUBECONFIG_FILE: $(yaml-quote "${WINDOWS_KUBEPROXY_KUBECONFIG_FILE}")
 WINDOWS_INFRA_CONTAINER: $(yaml-quote "${WINDOWS_INFRA_CONTAINER}")
 WINDOWS_ENABLE_PIGZ: $(yaml-quote "${WINDOWS_ENABLE_PIGZ}")
+WINDOWS_ENABLE_HYPERV: $(yaml-quote "${WINDOWS_ENABLE_HYPERV}")
 ENABLE_NODE_PROBLEM_DETECTOR: $(yaml-quote "${WINDOWS_ENABLE_NODE_PROBLEM_DETECTOR}")
 NODE_PROBLEM_DETECTOR_VERSION: $(yaml-quote "${NODE_PROBLEM_DETECTOR_VERSION}")
 NODE_PROBLEM_DETECTOR_TAR_HASH: $(yaml-quote "${NODE_PROBLEM_DETECTOR_TAR_HASH}")

cluster/gce/windows/configure.ps1

@@ -118,17 +118,32 @@ try {
 
   Dump-DebugInfoToConsole
 
+  $kube_env = Fetch-KubeEnv
+  Set-EnvironmentVars
+
+  # Set to true if there's a feature that needs a reboot
+  $restart_computer = $false
+
+  $should_enable_hyperv = Test-ShouldEnableHyperVFeature
+  $hyperv_feature_enabled = Test-HyperVFeatureEnabled
+  if ($should_enable_hyperv -and -not ($hyperv_feature_enabled)) {
+    Enable-HyperVFeature
+    Log-Output 'Restarting computer after enabling Windows Hyper-V feature'
+    $restart_computer = $true
+  }
+
   if (-not (Test-ContainersFeatureInstalled)) {
     Install-ContainersFeature
     Log-Output 'Restarting computer after enabling Windows Containers feature'
+    $restart_computer = $true
+  }
+
+  if ($restart_computer) {
     Restart-Computer -Force
     # Restart-Computer does not stop the rest of the script from executing.
     exit 0
   }
 
-  $kube_env = Fetch-KubeEnv
-  Set-EnvironmentVars
-
   # Set the TCP/IP Parameters to keep idle connections alive.
   Set-WindowsTCPParameters
 

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

@@ -295,6 +295,7 @@ function Set-EnvironmentVars {
     "MANIFESTS_DIR" = ${kube_env}['MANIFESTS_DIR']
     "INFRA_CONTAINER" = ${kube_env}['WINDOWS_INFRA_CONTAINER']
     "WINDOWS_ENABLE_PIGZ" = ${kube_env}['WINDOWS_ENABLE_PIGZ']
+    "WINDOWS_ENABLE_HYPERV" = ${kube_env}['WINDOWS_ENABLE_HYPERV']
     "ENABLE_NODE_PROBLEM_DETECTOR" = ${kube_env}['ENABLE_NODE_PROBLEM_DETECTOR']
     "NODEPROBLEMDETECTOR_KUBECONFIG_FILE" = ${kube_env}['WINDOWS_NODEPROBLEMDETECTOR_KUBECONFIG_FILE']
 
@@ -1386,6 +1387,24 @@ function Install-ContainersFeature {
   Install-WindowsFeature Containers
 }
 
+# Verifies if Hyper-V should be enabled in the node
+function Test-ShouldEnableHyperVFeature {
+  return "${env:WINDOWS_ENABLE_HYPERV}" -eq "true"
+}
+
+# Check if Hyper-V feature is enabled
+function Test-HyperVFeatureEnabled {
+  return ((Get-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V).State -eq 'Enabled')
+}
+
+# After this function returns, the computer must be restarted to complete
+# the installation!
+function Enable-HyperVFeature {
+  Log-Output "Enabling Windows 'HyperV' feature"
+  Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V -All -NoRestart
+  Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V-Management-PowerShell -All -NoRestart
+}
+
 function Test-DockerIsInstalled {
   return ((Get-Package `
                -ProviderName DockerMsftProvider `