Deprecate node-local-dns annotations (gardener#8067)

* Deprecate `node-local-dns` annotations

* Add warning for `node-local-dns` annotations

* Add TODO

* Address review

* Address review

pkg/api/core/shoot/warnings.go

@@ -24,6 +24,7 @@ import (
 
 	"github.com/gardener/gardener/pkg/apis/core"
 	"github.com/gardener/gardener/pkg/apis/core/helper"
+	v1beta1constants "github.com/gardener/gardener/pkg/apis/core/v1beta1/constants"
 	versionutils "github.com/gardener/gardener/pkg/utils/version"
 )
 
@@ -39,6 +40,9 @@ func GetWarnings(_ context.Context, shoot, oldShoot *core.Shoot, credentialsRota
 		warnings = append(warnings, "you should consider disabling the static token kubeconfig, see https://github.com/gardener/gardener/blob/master/docs/usage/shoot_access.md for details")
 	}
 
+	// TODO(acumino): Drop this warning in v1.78, with dropping of annotation to enable node-local-dns.
+	warnings = append(warnings, getWarningsForDeprecatedNodeLocalDNSLabels(shoot)...)
+
 	if oldShoot != nil {
 		warnings = append(warnings, getWarningsForDueCredentialsRotations(shoot, credentialsRotationInterval)...)
 		warnings = append(warnings, getWarningsForIncompleteCredentialsRotation(shoot, credentialsRotationInterval)...)
@@ -60,6 +64,24 @@ func GetWarnings(_ context.Context, shoot, oldShoot *core.Shoot, credentialsRota
 	return warnings
 }
 
+func getWarningsForDeprecatedNodeLocalDNSLabels(shoot *core.Shoot) []string {
+	var warnings []string
+
+	if _, ok := shoot.Annotations[v1beta1constants.AnnotationNodeLocalDNS]; ok {
+		warnings = append(warnings, fmt.Sprintf("annotation %v is deprecated. Use field `.spec.systemComponents.nodeLocalDNS.enabled` in Shoot instead. Switching on node-local-dns via shoot specification will roll the nodes even if node-local-dns was enabled beforehand via annotation.", v1beta1constants.AnnotationNodeLocalDNS))
+	}
+
+	if _, ok := shoot.Annotations[v1beta1constants.AnnotationNodeLocalDNSForceTcpToClusterDns]; ok {
+		warnings = append(warnings, fmt.Sprintf("annotation %v is deprecated. Use field `.spec.systemComponents.nodeLocalDNS.forceTCPToClusterDNS` in Shoot instead.", v1beta1constants.AnnotationNodeLocalDNSForceTcpToClusterDns))
+	}
+
+	if _, ok := shoot.Annotations[v1beta1constants.AnnotationNodeLocalDNSForceTcpToUpstreamDns]; ok {
+		warnings = append(warnings, fmt.Sprintf("annotation %v is deprecated. Use field `.spec.systemComponents.nodeLocalDNS.forceTCPToUpstreamDNS` in Shoot instead.", v1beta1constants.AnnotationNodeLocalDNSForceTcpToUpstreamDns))
+	}
+
+	return warnings
+}
+
 func getWarningsForDueCredentialsRotations(shoot *core.Shoot, credentialsRotationInterval time.Duration) []string {
 	if !isOldEnough(shoot.CreationTimestamp.Time, credentialsRotationInterval) {
 		return nil

pkg/api/core/shoot/warnings_test.go

@@ -26,6 +26,7 @@ import (
 
 	. "github.com/gardener/gardener/pkg/api/core/shoot"
 	"github.com/gardener/gardener/pkg/apis/core"
+	v1beta1constants "github.com/gardener/gardener/pkg/apis/core/v1beta1/constants"
 )
 
 var _ = Describe("Warnings", func() {
@@ -337,6 +338,33 @@ var _ = Describe("Warnings", func() {
 			})
 		})
 
+		Context("node-local-dns annotations", func() {
+			It("should return a warning when annotation `alpha.featuregates.shoot.gardener.cloud/node-local-dns` is present", func() {
+				shoot.Annotations = map[string]string{
+					v1beta1constants.AnnotationNodeLocalDNS: "true",
+				}
+				Expect(GetWarnings(ctx, shoot, nil, credentialsRotationInterval)).To(ContainElement(Equal("annotation alpha.featuregates.shoot.gardener.cloud/node-local-dns is deprecated. Use field `.spec.systemComponents.nodeLocalDNS.enabled` in Shoot instead. Switching on node-local-dns via shoot specification will roll the nodes even if node-local-dns was enabled beforehand via annotation.")))
+			})
+
+			It("should return a warning when annotation `alpha.featuregates.shoot.gardener.cloud/node-local-dns-force-tcp-to-cluster-dns` is present", func() {
+				shoot.Annotations = map[string]string{
+					v1beta1constants.AnnotationNodeLocalDNSForceTcpToClusterDns: "true",
+				}
+				Expect(GetWarnings(ctx, shoot, nil, credentialsRotationInterval)).To(ContainElement(Equal("annotation alpha.featuregates.shoot.gardener.cloud/node-local-dns-force-tcp-to-cluster-dns is deprecated. Use field `.spec.systemComponents.nodeLocalDNS.forceTCPToClusterDNS` in Shoot instead.")))
+			})
+
+			It("should return a warning when annotation `alpha.featuregates.shoot.gardener.cloud/node-local-dns-force-tcp-to-upstream-dns` is present", func() {
+				shoot.Annotations = map[string]string{
+					v1beta1constants.AnnotationNodeLocalDNSForceTcpToUpstreamDns: "true",
+				}
+				Expect(GetWarnings(ctx, shoot, nil, credentialsRotationInterval)).To(ContainElement(Equal("annotation alpha.featuregates.shoot.gardener.cloud/node-local-dns-force-tcp-to-upstream-dns is deprecated. Use field `.spec.systemComponents.nodeLocalDNS.forceTCPToUpstreamDNS` in Shoot instead.")))
+			})
+
+			It("should not return a warning when the node-local-dns related annotation is not present", func() {
+				Expect(GetWarnings(ctx, shoot, nil, credentialsRotationInterval)).To(BeEmpty())
+			})
+		})
+
 		It("should return a warning when podEvictionTimeout is set", func() {
 			shoot.Spec.Kubernetes.KubeControllerManager = &core.KubeControllerManagerConfig{
 				PodEvictionTimeout: &metav1.Duration{Duration: 2 * time.Minute},

pkg/apis/core/v1beta1/constants/types_constants.go

@@ -577,10 +577,16 @@ const (
 	// delays will not recompute it.
 	AnnotationShootCloudConfigExecutionMaxDelaySeconds = "shoot.gardener.cloud/cloud-config-execution-max-delay-seconds"
 	// AnnotationNodeLocalDNS enables a per node dns cache on the shoot cluster.
+	// Deprecated: This annotation is deprecated and will be removed in a future version.
+	// Use field `.spec.systemComponents.nodeLocalDNS.enabled` in Shoot instead.
 	AnnotationNodeLocalDNS = "alpha.featuregates.shoot.gardener.cloud/node-local-dns"
 	// AnnotationNodeLocalDNSForceTcpToClusterDns enforces upgrade to tcp connections for communication between node local and cluster dns.
+	// Deprecated: This annotation is deprecated and will be removed in a future version.
+	// Use field `.spec.systemComponents.nodeLocalDNS.forceTCPToClusterDNS` in Shoot instead.
 	AnnotationNodeLocalDNSForceTcpToClusterDns = "alpha.featuregates.shoot.gardener.cloud/node-local-dns-force-tcp-to-cluster-dns"
 	// AnnotationNodeLocalDNSForceTcpToUpstreamDns enforces upgrade to tcp connections for communication between node local and upstream dns.
+	// Deprecated: This annotation is deprecated and will be removed in a future version.
+	// Use field `.spec.systemComponents.nodeLocalDNS.forceTCPToUpstreamDNS` in Shoot instead.
 	AnnotationNodeLocalDNSForceTcpToUpstreamDns = "alpha.featuregates.shoot.gardener.cloud/node-local-dns-force-tcp-to-upstream-dns"
 	// AnnotationCoreDNSRewritingDisabled disables core dns query rewriting even if the corresponding feature gate is enabled.
 	AnnotationCoreDNSRewritingDisabled = "alpha.featuregates.shoot.gardener.cloud/core-dns-rewriting-disabled"