api: Add min ready seconds & availablereplicas for statefulsets

pkg/apis/apps/types.go

@@ -157,6 +157,13 @@ type StatefulSetSpec struct {
 	// consists of all revisions not represented by a currently applied
 	// StatefulSetSpec version. The default value is 10.
 	RevisionHistoryLimit *int32
+
+	// Minimum number of seconds for which a newly created pod should be ready
+	// without any of its container crashing for it to be considered available.
+	// Defaults to 0 (pod will be considered available as soon as it is ready)
+	// This is an alpha field and requires enabling StatefulSetMinReadySeconds feature gate.
+	// +optional
+	MinReadySeconds int32
 }
 
 // StatefulSetStatus represents the current state of a StatefulSet.
@@ -196,6 +203,12 @@ type StatefulSetStatus struct {
 
 	// Represents the latest available observations of a statefulset's current state.
 	Conditions []StatefulSetCondition
+
+	// Total number of available pods (ready for at least minReadySeconds) targeted by this statefulset.
+	// This is an alpha field and requires enabling StatefulSetMinReadySeconds feature gate.
+	// Remove omitempty when graduating to beta
+	// +optional
+	AvailableReplicas int32
 }
 
 // StatefulSetConditionType describes the condition types of StatefulSets.

pkg/apis/apps/v1/defaults_test.go

@@ -208,6 +208,7 @@ func TestSetDefaultStatefulSet(t *testing.T) {
 				},
 				Spec: appsv1.StatefulSetSpec{
 					Replicas:            &defaultReplicas,
+					MinReadySeconds:     int32(0),
 					Template:            defaultTemplate,
 					PodManagementPolicy: appsv1.OrderedReadyPodManagement,
 					UpdateStrategy: appsv1.StatefulSetUpdateStrategy{
@@ -235,6 +236,7 @@ func TestSetDefaultStatefulSet(t *testing.T) {
 				},
 				Spec: appsv1.StatefulSetSpec{
 					Replicas:            &defaultReplicas,
+					MinReadySeconds:     int32(0),
 					Template:            defaultTemplate,
 					PodManagementPolicy: appsv1.OrderedReadyPodManagement,
 					UpdateStrategy: appsv1.StatefulSetUpdateStrategy{
@@ -257,6 +259,7 @@ func TestSetDefaultStatefulSet(t *testing.T) {
 				},
 				Spec: appsv1.StatefulSetSpec{
 					Replicas:            &defaultReplicas,
+					MinReadySeconds:     int32(0),
 					Template:            defaultTemplate,
 					PodManagementPolicy: appsv1.ParallelPodManagement,
 					UpdateStrategy: appsv1.StatefulSetUpdateStrategy{
@@ -286,6 +289,7 @@ func TestSetDefaultStatefulSet(t *testing.T) {
 				},
 				Spec: appsv1.StatefulSetSpec{
 					Replicas:            &defaultReplicas,
+					MinReadySeconds:     int32(0),
 					Template:            defaultTemplate,
 					PodManagementPolicy: appsv1.OrderedReadyPodManagement,
 					UpdateStrategy: appsv1.StatefulSetUpdateStrategy{

pkg/apis/apps/v1beta1/defaults.go

@@ -60,7 +60,6 @@ func SetDefaults_StatefulSet(obj *appsv1beta1.StatefulSet) {
 		obj.Spec.UpdateStrategy.RollingUpdate.Partition = new(int32)
 		*obj.Spec.UpdateStrategy.RollingUpdate.Partition = 0
 	}
-
 }
 
 // SetDefaults_Deployment sets additional defaults compared to its counterpart

pkg/apis/apps/v1beta2/defaults_test.go

@@ -207,6 +207,7 @@ func TestSetDefaultStatefulSet(t *testing.T) {
 				},
 				Spec: appsv1beta2.StatefulSetSpec{
 					Replicas:            &defaultReplicas,
+					MinReadySeconds:     int32(0),
 					Template:            defaultTemplate,
 					PodManagementPolicy: appsv1beta2.OrderedReadyPodManagement,
 					UpdateStrategy: appsv1beta2.StatefulSetUpdateStrategy{
@@ -234,6 +235,7 @@ func TestSetDefaultStatefulSet(t *testing.T) {
 				},
 				Spec: appsv1beta2.StatefulSetSpec{
 					Replicas:            &defaultReplicas,
+					MinReadySeconds:     int32(0),
 					Template:            defaultTemplate,
 					PodManagementPolicy: appsv1beta2.OrderedReadyPodManagement,
 					UpdateStrategy: appsv1beta2.StatefulSetUpdateStrategy{
@@ -256,6 +258,7 @@ func TestSetDefaultStatefulSet(t *testing.T) {
 				},
 				Spec: appsv1beta2.StatefulSetSpec{
 					Replicas:            &defaultReplicas,
+					MinReadySeconds:     int32(0),
 					Template:            defaultTemplate,
 					PodManagementPolicy: appsv1beta2.ParallelPodManagement,
 					UpdateStrategy: appsv1beta2.StatefulSetUpdateStrategy{

pkg/apis/apps/validation/validation.go

@@ -109,6 +109,9 @@ func ValidateStatefulSetSpec(spec *apps.StatefulSetSpec, fldPath *field.Path, op
 	}
 
 	allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(spec.Replicas), fldPath.Child("replicas"))...)
+	if utilfeature.DefaultFeatureGate.Enabled(features.StatefulSetMinReadySeconds) {
+		allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(spec.MinReadySeconds), fldPath.Child("minReadySeconds"))...)
+	}
 	if spec.Selector == nil {
 		allErrs = append(allErrs, field.Required(fldPath.Child("selector"), ""))
 	} else {
@@ -152,11 +155,21 @@ func ValidateStatefulSetUpdate(statefulSet, oldStatefulSet *apps.StatefulSet) fi
 	newStatefulSetClone.Spec.Replicas = oldStatefulSet.Spec.Replicas             // +k8s:verify-mutation:reason=clone
 	newStatefulSetClone.Spec.Template = oldStatefulSet.Spec.Template             // +k8s:verify-mutation:reason=clone
 	newStatefulSetClone.Spec.UpdateStrategy = oldStatefulSet.Spec.UpdateStrategy // +k8s:verify-mutation:reason=clone
+	if utilfeature.DefaultFeatureGate.Enabled(features.StatefulSetMinReadySeconds) {
+		newStatefulSetClone.Spec.MinReadySeconds = oldStatefulSet.Spec.MinReadySeconds // +k8s:verify-mutation:reason=clone
+	}
 	if !apiequality.Semantic.DeepEqual(newStatefulSetClone.Spec, oldStatefulSet.Spec) {
-		allErrs = append(allErrs, field.Forbidden(field.NewPath("spec"), "updates to statefulset spec for fields other than 'replicas', 'template', and 'updateStrategy' are forbidden"))
+		if utilfeature.DefaultFeatureGate.Enabled(features.StatefulSetMinReadySeconds) {
+			allErrs = append(allErrs, field.Forbidden(field.NewPath("spec"), "updates to statefulset spec for fields other than 'replicas', 'template', 'minReadySeconds' and 'updateStrategy' are forbidden"))
+		} else {
+			allErrs = append(allErrs, field.Forbidden(field.NewPath("spec"), "updates to statefulset spec for fields other than 'replicas', 'template' and 'updateStrategy' are forbidden"))
+		}
 	}
 
 	allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(statefulSet.Spec.Replicas), field.NewPath("spec", "replicas"))...)
+	if utilfeature.DefaultFeatureGate.Enabled(features.StatefulSetMinReadySeconds) {
+		allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(statefulSet.Spec.MinReadySeconds), field.NewPath("spec", "minReadySeconds"))...)
+	}
 	return allErrs
 }
 
@@ -168,6 +181,9 @@ func ValidateStatefulSetStatus(status *apps.StatefulSetStatus, fieldPath *field.
 	allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(status.ReadyReplicas), fieldPath.Child("readyReplicas"))...)
 	allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(status.CurrentReplicas), fieldPath.Child("currentReplicas"))...)
 	allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(status.UpdatedReplicas), fieldPath.Child("updatedReplicas"))...)
+	if utilfeature.DefaultFeatureGate.Enabled(features.StatefulSetMinReadySeconds) {
+		allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(status.AvailableReplicas), fieldPath.Child("availableReplicas"))...)
+	}
 	if status.ObservedGeneration != nil {
 		allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(*status.ObservedGeneration), fieldPath.Child("observedGeneration"))...)
 	}
@@ -185,6 +201,14 @@ func ValidateStatefulSetStatus(status *apps.StatefulSetStatus, fieldPath *field.
 	if status.UpdatedReplicas > status.Replicas {
 		allErrs = append(allErrs, field.Invalid(fieldPath.Child("updatedReplicas"), status.UpdatedReplicas, msg))
 	}
+	if utilfeature.DefaultFeatureGate.Enabled(features.StatefulSetMinReadySeconds) {
+		if status.AvailableReplicas > status.Replicas {
+			allErrs = append(allErrs, field.Invalid(fieldPath.Child("availableReplicas"), status.AvailableReplicas, msg))
+		}
+		if status.AvailableReplicas > status.ReadyReplicas {
+			allErrs = append(allErrs, field.Invalid(fieldPath.Child("availableReplicas"), status.AvailableReplicas, "cannot be greater than readyReplicas"))
+		}
+	}
 
 	return allErrs
 }