Set the deletion grace period to 1 on forced VM restarts

In order to allow a swift and safe restart, set the deletion grace
period to 1 on the pod delete when a force restart is requested.

One is the shortest safe restart period where we don't risk a
split-brain scenario for VMs, since Zero effectively deletes the pod
right away.

This leads to the following outcome:
 * If a guest OS is stuck, people get a swift restart.
 * Users don't risk data corruption.
 * Reserving a force pod delete for situations where the cluster is
   unhealthy.

Signed-off-by: Roman Mohr <rmohr@google.com>

pkg/virt-api/rest/BUILD.bazel

@@ -53,6 +53,7 @@ go_library(
         "//vendor/k8s.io/client-go/kubernetes/typed/authorization/v1:go_default_library",
         "//vendor/k8s.io/client-go/rest:go_default_library",
         "//vendor/k8s.io/client-go/util/flowcontrol:go_default_library",
+        "//vendor/k8s.io/utils/pointer:go_default_library",
         "//vendor/kubevirt.io/containerized-data-importer-api/pkg/apis/core/v1beta1:go_default_library",
     ],
 )

pkg/virt-api/rest/subresource.go

@@ -41,6 +41,7 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/json"
 	"k8s.io/apimachinery/pkg/util/yaml"
+	"k8s.io/utils/pointer"
 
 	"kubevirt.io/kubevirt/pkg/util/status"
 
@@ -439,8 +440,8 @@ func (app *SubresourceAPIApp) RestartVMRequestHandler(request *restful.Request,
 				response.WriteHeader(http.StatusAccepted)
 				return
 			}
-			// set terminationGracePeriod and delete the VMI pod to trigger a forced restart
-			err = app.virtCli.CoreV1().Pods(namespace).Delete(context.Background(), vmiPodname, k8smetav1.DeleteOptions{GracePeriodSeconds: bodyStruct.GracePeriodSeconds})
+			// set terminationGracePeriod to 1 (which is the shorted safe restart period) and delete the VMI pod to trigger a swift restart.
+			err = app.virtCli.CoreV1().Pods(namespace).Delete(context.Background(), vmiPodname, k8smetav1.DeleteOptions{GracePeriodSeconds: pointer.Int64(1)})
 			if err != nil {
 				if !errors.IsNotFound(err) {
 					writeError(errors.NewInternalError(err), response)