Added field CollisionCount to StatefulSetStatus

This is the first step towards fixing kubernetes#49909. The field will be used for collision avoidance when the StatefulSet controller creates name for the newest ControllerRevision, which will be done in a subsequent PR.

pkg/apis/apps/types.go

@@ -187,6 +187,12 @@ type StatefulSetStatus struct {
 	// updateRevision, if not empty, indicates the version of the StatefulSet used to generate Pods in the sequence
 	// [replicas-updatedReplicas,replicas)
 	UpdateRevision string
+
+	// Count of hash collisions for the StatefulSet. The StatefulSet controller
+	// uses this field as a collision avoidance mechanism when it needs to
+	// create the name for the newest ControllerRevision.
+	// +optional
+	CollisionCount *int64
 }
 
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object

pkg/apis/apps/validation/validation.go

@@ -163,9 +163,39 @@ func ValidateStatefulSetUpdate(statefulSet, oldStatefulSet *apps.StatefulSet) fi
 	return allErrs
 }
 
+// ValidateStatefulSetStatus validates a StatefulSetStatus.
+func ValidateStatefulSetStatus(status *apps.StatefulSetStatus, fieldPath *field.Path) field.ErrorList {
+	allErrs := field.ErrorList{}
+
+	allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(status.Replicas), fieldPath.Child("replicas"))...)
+	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 status.ObservedGeneration != nil {
+		allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(*status.ObservedGeneration), fieldPath.Child("observedGeneration"))...)
+	}
+	if status.CollisionCount != nil {
+		allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(*status.CollisionCount), fieldPath.Child("collisionCount"))...)
+	}
+
+	msg := "cannot be greater than status.replicas"
+	if status.ReadyReplicas > status.Replicas {
+		allErrs = append(allErrs, field.Invalid(fieldPath.Child("readyReplicas"), status.ReadyReplicas, msg))
+	}
+	if status.CurrentReplicas > status.Replicas {
+		allErrs = append(allErrs, field.Invalid(fieldPath.Child("currentReplicas"), status.CurrentReplicas, msg))
+	}
+	if status.UpdatedReplicas > status.Replicas {
+		allErrs = append(allErrs, field.Invalid(fieldPath.Child("updatedReplicas"), status.UpdatedReplicas, msg))
+	}
+
+	return allErrs
+}
+
 // ValidateStatefulSetStatusUpdate tests if required fields in the StatefulSet are set.
 func ValidateStatefulSetStatusUpdate(statefulSet, oldStatefulSet *apps.StatefulSet) field.ErrorList {
 	allErrs := field.ErrorList{}
+	allErrs = append(allErrs, ValidateStatefulSetStatus(&statefulSet.Status, field.NewPath("status"))...)
 	allErrs = append(allErrs, apivalidation.ValidateObjectMetaUpdate(&statefulSet.ObjectMeta, &oldStatefulSet.ObjectMeta, field.NewPath("metadata"))...)
 	// TODO: Validate status.
 	return allErrs

pkg/apis/apps/validation/validation_test.go

@@ -20,8 +20,11 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/davecgh/go-spew/spew"
+
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/validation/field"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/apis/apps"
 )
@@ -300,6 +303,120 @@ func TestValidateStatefulSet(t *testing.T) {
 	}
 }
 
+func TestValidateStatefulSetStatus(t *testing.T) {
+	minusOne := int64(-1)
+	tests := []struct {
+		name               string
+		replicas           int32
+		readyReplicas      int32
+		currentReplicas    int32
+		updatedReplicas    int32
+		observedGeneration *int64
+		collisionCount     *int64
+		expectedErr        bool
+	}{
+		{
+			name:            "valid status",
+			replicas:        3,
+			readyReplicas:   3,
+			currentReplicas: 2,
+			updatedReplicas: 1,
+			expectedErr:     false,
+		},
+		{
+			name:            "invalid replicas",
+			replicas:        -1,
+			readyReplicas:   3,
+			currentReplicas: 2,
+			updatedReplicas: 1,
+			expectedErr:     true,
+		},
+		{
+			name:            "invalid readyReplicas",
+			replicas:        3,
+			readyReplicas:   -1,
+			currentReplicas: 2,
+			updatedReplicas: 1,
+			expectedErr:     true,
+		},
+		{
+			name:            "invalid currentReplicas",
+			replicas:        3,
+			readyReplicas:   3,
+			currentReplicas: -1,
+			updatedReplicas: 1,
+			expectedErr:     true,
+		},
+		{
+			name:            "invalid updatedReplicas",
+			replicas:        3,
+			readyReplicas:   3,
+			currentReplicas: 2,
+			updatedReplicas: -1,
+			expectedErr:     true,
+		},
+		{
+			name:               "invalid observedGeneration",
+			replicas:           3,
+			readyReplicas:      3,
+			currentReplicas:    2,
+			updatedReplicas:    1,
+			observedGeneration: &minusOne,
+			expectedErr:        true,
+		},
+		{
+			name:            "invalid collisionCount",
+			replicas:        3,
+			readyReplicas:   3,
+			currentReplicas: 2,
+			updatedReplicas: 1,
+			collisionCount:  &minusOne,
+			expectedErr:     true,
+		},
+		{
+			name:            "readyReplicas greater than replicas",
+			replicas:        3,
+			readyReplicas:   4,
+			currentReplicas: 2,
+			updatedReplicas: 1,
+			expectedErr:     true,
+		},
+		{
+			name:            "currentReplicas greater than replicas",
+			replicas:        3,
+			readyReplicas:   3,
+			currentReplicas: 4,
+			updatedReplicas: 1,
+			expectedErr:     true,
+		},
+		{
+			name:            "updatedReplicas greater than replicas",
+			replicas:        3,
+			readyReplicas:   3,
+			currentReplicas: 2,
+			updatedReplicas: 4,
+			expectedErr:     true,
+		},
+	}
+
+	for _, test := range tests {
+		status := apps.StatefulSetStatus{
+			Replicas:           test.replicas,
+			ReadyReplicas:      test.readyReplicas,
+			CurrentReplicas:    test.currentReplicas,
+			UpdatedReplicas:    test.updatedReplicas,
+			ObservedGeneration: test.observedGeneration,
+			CollisionCount:     test.collisionCount,
+		}
+
+		errs := ValidateStatefulSetStatus(&status, field.NewPath("status"))
+		if hasErr := len(errs) > 0; hasErr != test.expectedErr {
+			errString := spew.Sprintf("%#v", errs)
+			t.Errorf("%s: expected error: %t, got error: %t\nerrors: %s", test.name, test.expectedErr, hasErr, errString)
+		}
+	}
+}
+
 func TestValidateStatefulSetUpdate(t *testing.T) {
 	validLabels := map[string]string{"a": "b"}
 	validPodTemplate := api.PodTemplate{