Enable DownwardMetrics FeatureGate (#1503)

github.com/kubevirt/kubevirt/pull/5502
introduced a new Kubevirt feature named
downwardMetrics to expose host metrics
to guests.
The feature is controlled by a feature
gate named "DownwardMetrics".
Enable it in the list of HCO
opinionated feature gates.

Fixes: https://bugzilla.redhat.com/1991691

Signed-off-by: Simone Tiraboschi <stirabos@redhat.com>

Co-authored-by: Simone Tiraboschi <stirabos@redhat.com>

pkg/controller/hyperconverged/hyperconverged_controller_test.go

@@ -172,7 +172,7 @@ var _ = Describe("HyperconvergedController", func() {
 				Expect(kvList.Items).Should(HaveLen(1))
 				kv := kvList.Items[0]
 				Expect(kv.Spec.Configuration.DeveloperConfiguration).ToNot(BeNil())
-				Expect(kv.Spec.Configuration.DeveloperConfiguration.FeatureGates).To(HaveLen(12))
+				Expect(kv.Spec.Configuration.DeveloperConfiguration.FeatureGates).To(HaveLen(13))
 
 				Expect(kv.Spec.Configuration.DeveloperConfiguration.FeatureGates).To(ContainElements(
 					"DataVolumes",
@@ -185,7 +185,9 @@ var _ = Describe("HyperconvergedController", func() {
 					"GPU",
 					"HostDevices",
 					"WithHostModelCPU",
-					"HypervStrictCheck"),
+					"HypervStrictCheck",
+					"DownwardMetrics",
+				),
 				)
 				Expect(kv.Spec.Configuration.DeveloperConfiguration.FeatureGates).To(ContainElement("WithHostPassthroughCPU"))
 			})

pkg/controller/operands/kubevirt.go

@@ -82,6 +82,9 @@ const (
 
 	// Allow assigning host devices to virtual machines
 	kvHostDevicesGate = "HostDevices"
+
+	// Add downwardMetrics volume to expose a limited set of host metrics to guests
+	kvDownwardMetricsGate = "DownwardMetrics"
 )
 
 var (
@@ -95,6 +98,7 @@ var (
 		kvHotplugVolumesGate,
 		kvGPUGate,
 		kvHostDevicesGate,
+		kvDownwardMetricsGate,
 	}
 
 	// holds a list of mandatory KubeVirt feature gates. Some of them are the hard coded feature gates and some of