api: Allow MaxSurge to be set on DaemonSets during update

pkg/apis/apps/fuzzer/fuzzer.go

@@ -118,11 +118,13 @@ var Funcs = func(codecs runtimeserializer.CodecFactory) []interface{} {
 				rollingUpdate := apps.RollingUpdateDaemonSet{}
 				if c.RandBool() {
 					if c.RandBool() {
-						rollingUpdate.MaxUnavailable = intstr.FromInt(1 + int(c.Rand.Int31()))
+						rollingUpdate.MaxUnavailable = intstr.FromInt(int(c.Rand.Int31()))
+						rollingUpdate.MaxSurge = intstr.FromInt(int(c.Rand.Int31()))
 					} else {
-						rollingUpdate.MaxUnavailable = intstr.FromString(fmt.Sprintf("%d%%", 1+c.Rand.Int31()))
+						rollingUpdate.MaxSurge = intstr.FromString(fmt.Sprintf("%d%%", c.Rand.Int31()))
 					}
 				}
+
 				j.RollingUpdate = &rollingUpdate
 			}
 		},

pkg/apis/apps/types.go

@@ -532,19 +532,41 @@ type RollingUpdateDaemonSet struct {
 	// The maximum number of DaemonSet pods that can be unavailable during the
 	// update. Value can be an absolute number (ex: 5) or a percentage of total
 	// number of DaemonSet pods at the start of the update (ex: 10%). Absolute
-	// number is calculated from percentage by rounding up.
-	// This cannot be 0.
+	// number is calculated from percentage by rounding down to a minimum of one.
+	// This cannot be 0 if MaxSurge is 0
 	// Default value is 1.
 	// Example: when this is set to 30%, at most 30% of the total number of nodes
 	// that should be running the daemon pod (i.e. status.desiredNumberScheduled)
-	// can have their pods stopped for an update at any given
-	// time. The update starts by stopping at most 30% of those DaemonSet pods
-	// and then brings up new DaemonSet pods in their place. Once the new pods
-	// are available, it then proceeds onto other DaemonSet pods, thus ensuring
-	// that at least 70% of original number of DaemonSet pods are available at
-	// all times during the update.
+	// can have their pods stopped for an update at any given time. The update
+	// starts by stopping at most 30% of those DaemonSet pods and then brings
+	// up new DaemonSet pods in their place. Once the new pods are available,
+	// it then proceeds onto other DaemonSet pods, thus ensuring that at least
+	// 70% of original number of DaemonSet pods are available at all times during
+	// the update.
 	// +optional
 	MaxUnavailable intstr.IntOrString
+
+	// The maximum number of nodes with an existing available DaemonSet pod that
+	// can have an updated DaemonSet pod during during an update.
+	// Value can be an absolute number (ex: 5) or a percentage of desired pods (ex: 10%).
+	// This can not be 0 if MaxUnavailable is 0.
+	// Absolute number is calculated from percentage by rounding up to a minimum of 1.
+	// Default value is 0.
+	// Example: when this is set to 30%, at most 30% of the total number of nodes
+	// that should be running the daemon pod (i.e. status.desiredNumberScheduled)
+	// can have their a new pod created before the old pod is marked as deleted.
+	// The update starts by launching new pods on 30% of nodes. Once an updated
+	// pod is available (Ready for at least minReadySeconds) the old DaemonSet pod
+	// on that node is marked deleted. If the old pod becomes unavailable for any
+	// reason (Ready transitions to false, is evicted, or is drained) an updated
+	// pod is immediatedly created on that node without considering surge limits.
+	// Allowing surge implies the possibility that the resources consumed by the
+	// daemonset on any given node can double if the readiness check fails, and
+	// so resource intensive daemonsets should take into account that they may
+	// cause evictions during disruption.
+	// This is an alpha field and requires enabling DaemonSetUpdateSurge feature gate.
+	// +optional
+	MaxSurge intstr.IntOrString
 }
 
 // DaemonSetSpec is the specification of a daemon set.

pkg/apis/apps/v1/conversion_test.go

@@ -20,7 +20,7 @@ import (
 	"testing"
 
 	appsv1 "k8s.io/api/apps/v1"
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	apiequality "k8s.io/apimachinery/pkg/api/equality"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
@@ -226,13 +226,14 @@ func TestV1StatefulSetUpdateStrategyConversion(t *testing.T) {
 
 func TestV1RollingUpdateDaemonSetConversion(t *testing.T) {
 	intorstr := intstr.FromInt(1)
+	maxSurge := intstr.FromInt(0)
 	testcases := map[string]struct {
 		rollingUpdateDs1 *apps.RollingUpdateDaemonSet
 		rollingUpdateDs2 *appsv1.RollingUpdateDaemonSet
 	}{
 		"RollingUpdateDaemonSet Conversion 2": {
-			rollingUpdateDs1: &apps.RollingUpdateDaemonSet{MaxUnavailable: intorstr},
-			rollingUpdateDs2: &appsv1.RollingUpdateDaemonSet{MaxUnavailable: &intorstr},
+			rollingUpdateDs1: &apps.RollingUpdateDaemonSet{MaxUnavailable: intorstr, MaxSurge: maxSurge},
+			rollingUpdateDs2: &appsv1.RollingUpdateDaemonSet{MaxUnavailable: &intorstr, MaxSurge: &maxSurge},
 		},
 	}
 

pkg/apis/apps/v1/defaults.go

@@ -84,6 +84,11 @@ func SetDefaults_DaemonSet(obj *appsv1.DaemonSet) {
 			maxUnavailable := intstr.FromInt(1)
 			updateStrategy.RollingUpdate.MaxUnavailable = &maxUnavailable
 		}
+		if updateStrategy.RollingUpdate.MaxSurge == nil {
+			// Set default MaxSurge as 0 by default.
+			maxSurge := intstr.FromInt(0)
+			updateStrategy.RollingUpdate.MaxSurge = &maxSurge
+		}
 	}
 	if obj.Spec.RevisionHistoryLimit == nil {
 		obj.Spec.RevisionHistoryLimit = new(int32)

pkg/apis/apps/v1/defaults_test.go

@@ -21,7 +21,7 @@ import (
 	"testing"
 
 	appsv1 "k8s.io/api/apps/v1"
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	apiequality "k8s.io/apimachinery/pkg/api/equality"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -38,6 +38,7 @@ import (
 func TestSetDefaultDaemonSetSpec(t *testing.T) {
 	defaultLabels := map[string]string{"foo": "bar"}
 	maxUnavailable := intstr.FromInt(1)
+	maxSurge := intstr.FromInt(0)
 	period := int64(v1.DefaultTerminationGracePeriodSeconds)
 	defaultTemplate := v1.PodTemplateSpec{
 		Spec: v1.PodSpec{
@@ -80,6 +81,7 @@ func TestSetDefaultDaemonSetSpec(t *testing.T) {
 						Type: appsv1.RollingUpdateDaemonSetStrategyType,
 						RollingUpdate: &appsv1.RollingUpdateDaemonSet{
 							MaxUnavailable: &maxUnavailable,
+							MaxSurge:       &maxSurge,
 						},
 					},
 					RevisionHistoryLimit: utilpointer.Int32Ptr(10),
@@ -110,6 +112,7 @@ func TestSetDefaultDaemonSetSpec(t *testing.T) {
 						Type: appsv1.RollingUpdateDaemonSetStrategyType,
 						RollingUpdate: &appsv1.RollingUpdateDaemonSet{
 							MaxUnavailable: &maxUnavailable,
+							MaxSurge:       &maxSurge,
 						},
 					},
 					RevisionHistoryLimit: utilpointer.Int32Ptr(1),
@@ -146,6 +149,7 @@ func TestSetDefaultDaemonSetSpec(t *testing.T) {
 						Type: appsv1.RollingUpdateDaemonSetStrategyType,
 						RollingUpdate: &appsv1.RollingUpdateDaemonSet{
 							MaxUnavailable: &maxUnavailable,
+							MaxSurge:       &maxSurge,
 						},
 					},
 					RevisionHistoryLimit: utilpointer.Int32Ptr(10),

pkg/apis/apps/v1beta2/conversion_test.go

@@ -20,7 +20,7 @@ import (
 	"testing"
 
 	"k8s.io/api/apps/v1beta2"
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
 	"k8s.io/kubernetes/pkg/api/legacyscheme"
 	"k8s.io/kubernetes/pkg/apis/apps"
@@ -153,13 +153,14 @@ func TestV1beta2StatefulSetUpdateStrategyConversion(t *testing.T) {
 
 func TestV1beta2RollingUpdateDaemonSetConversion(t *testing.T) {
 	intorstr := intstr.FromInt(1)
+	maxSurge := intstr.FromInt(0)
 	testcases := map[string]struct {
 		rollingUpdateDs1 *apps.RollingUpdateDaemonSet
 		rollingUpdateDs2 *v1beta2.RollingUpdateDaemonSet
 	}{
 		"RollingUpdateDaemonSet Conversion 2": {
-			rollingUpdateDs1: &apps.RollingUpdateDaemonSet{MaxUnavailable: intorstr},
-			rollingUpdateDs2: &v1beta2.RollingUpdateDaemonSet{MaxUnavailable: &intorstr},
+			rollingUpdateDs1: &apps.RollingUpdateDaemonSet{MaxUnavailable: intorstr, MaxSurge: maxSurge},
+			rollingUpdateDs2: &v1beta2.RollingUpdateDaemonSet{MaxUnavailable: &intorstr, MaxSurge: &maxSurge},
 		},
 	}
 

pkg/apis/apps/v1beta2/defaults.go

@@ -41,6 +41,11 @@ func SetDefaults_DaemonSet(obj *appsv1beta2.DaemonSet) {
 			maxUnavailable := intstr.FromInt(1)
 			updateStrategy.RollingUpdate.MaxUnavailable = &maxUnavailable
 		}
+		if updateStrategy.RollingUpdate.MaxSurge == nil {
+			// Set default MaxSurge as 0 by default.
+			maxSurge := intstr.FromInt(0)
+			updateStrategy.RollingUpdate.MaxSurge = &maxSurge
+		}
 	}
 	if obj.Spec.RevisionHistoryLimit == nil {
 		obj.Spec.RevisionHistoryLimit = new(int32)

pkg/apis/apps/v1beta2/defaults_test.go

@@ -21,7 +21,7 @@ import (
 	"testing"
 
 	appsv1beta2 "k8s.io/api/apps/v1beta2"
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	apiequality "k8s.io/apimachinery/pkg/api/equality"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -38,6 +38,7 @@ import (
 func TestSetDefaultDaemonSetSpec(t *testing.T) {
 	defaultLabels := map[string]string{"foo": "bar"}
 	maxUnavailable := intstr.FromInt(1)
+	maxSurge := intstr.FromInt(0)
 	period := int64(v1.DefaultTerminationGracePeriodSeconds)
 	defaultTemplate := v1.PodTemplateSpec{
 		Spec: v1.PodSpec{
@@ -80,6 +81,7 @@ func TestSetDefaultDaemonSetSpec(t *testing.T) {
 						Type: appsv1beta2.RollingUpdateDaemonSetStrategyType,
 						RollingUpdate: &appsv1beta2.RollingUpdateDaemonSet{
 							MaxUnavailable: &maxUnavailable,
+							MaxSurge:       &maxSurge,
 						},
 					},
 					RevisionHistoryLimit: utilpointer.Int32Ptr(10),
@@ -110,6 +112,7 @@ func TestSetDefaultDaemonSetSpec(t *testing.T) {
 						Type: appsv1beta2.RollingUpdateDaemonSetStrategyType,
 						RollingUpdate: &appsv1beta2.RollingUpdateDaemonSet{
 							MaxUnavailable: &maxUnavailable,
+							MaxSurge:       &maxSurge,
 						},
 					},
 					RevisionHistoryLimit: utilpointer.Int32Ptr(1),
@@ -146,6 +149,7 @@ func TestSetDefaultDaemonSetSpec(t *testing.T) {
 						Type: appsv1beta2.RollingUpdateDaemonSetStrategyType,
 						RollingUpdate: &appsv1beta2.RollingUpdateDaemonSet{
 							MaxUnavailable: &maxUnavailable,
+							MaxSurge:       &maxSurge,
 						},
 					},
 					RevisionHistoryLimit: utilpointer.Int32Ptr(10),

pkg/apis/apps/validation/BUILD

@@ -14,6 +14,7 @@ go_library(
         "//pkg/apis/apps:go_default_library",
         "//pkg/apis/core:go_default_library",
         "//pkg/apis/core/validation:go_default_library",
+        "//pkg/features:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/api/equality:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/api/validation:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
@@ -22,6 +23,7 @@ go_library(
         "//staging/src/k8s.io/apimachinery/pkg/util/intstr:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/validation:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/util/feature:go_default_library",
     ],
 )
 

pkg/apis/apps/validation/validation.go

@@ -28,9 +28,11 @@ import (
 	"k8s.io/apimachinery/pkg/util/intstr"
 	"k8s.io/apimachinery/pkg/util/validation"
 	"k8s.io/apimachinery/pkg/util/validation/field"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/kubernetes/pkg/apis/apps"
 	api "k8s.io/kubernetes/pkg/apis/core"
 	apivalidation "k8s.io/kubernetes/pkg/apis/core/validation"
+	"k8s.io/kubernetes/pkg/features"
 )
 
 // ValidateStatefulSetName can be used to check whether the given StatefulSet name is valid.
@@ -343,14 +345,35 @@ func ValidateDaemonSetSpec(spec *apps.DaemonSetSpec, fldPath *field.Path, opts a
 
 // ValidateRollingUpdateDaemonSet validates a given RollingUpdateDaemonSet.
 func ValidateRollingUpdateDaemonSet(rollingUpdate *apps.RollingUpdateDaemonSet, fldPath *field.Path) field.ErrorList {
-	allErrs := field.ErrorList{}
-	allErrs = append(allErrs, ValidatePositiveIntOrPercent(rollingUpdate.MaxUnavailable, fldPath.Child("maxUnavailable"))...)
-	if getIntOrPercentValue(rollingUpdate.MaxUnavailable) == 0 {
-		// MaxUnavailable cannot be 0.
-		allErrs = append(allErrs, field.Invalid(fldPath.Child("maxUnavailable"), rollingUpdate.MaxUnavailable, "cannot be 0"))
+	var allErrs field.ErrorList
+	if utilfeature.DefaultFeatureGate.Enabled(features.DaemonSetUpdateSurge) {
+		// Validate both fields are positive ints or have a percentage value
+		allErrs = append(allErrs, ValidatePositiveIntOrPercent(rollingUpdate.MaxUnavailable, fldPath.Child("maxUnavailable"))...)
+		allErrs = append(allErrs, ValidatePositiveIntOrPercent(rollingUpdate.MaxSurge, fldPath.Child("maxSurge"))...)
+
+		// Validate that MaxUnavailable and MaxSurge are not more than 100%.
+		allErrs = append(allErrs, IsNotMoreThan100Percent(rollingUpdate.MaxUnavailable, fldPath.Child("maxUnavailable"))...)
+		allErrs = append(allErrs, IsNotMoreThan100Percent(rollingUpdate.MaxSurge, fldPath.Child("maxSurge"))...)
+
+		// Validate exactly one of MaxSurge or MaxUnavailable is non-zero
+		hasUnavailable := getIntOrPercentValue(rollingUpdate.MaxUnavailable) != 0
+		hasSurge := getIntOrPercentValue(rollingUpdate.MaxSurge) != 0
+		switch {
+		case hasUnavailable && hasSurge:
+			allErrs = append(allErrs, field.Invalid(fldPath.Child("maxSurge"), rollingUpdate.MaxSurge, "may not be set when maxUnavailable is non-zero"))
+		case !hasUnavailable && !hasSurge:
+			allErrs = append(allErrs, field.Required(fldPath.Child("maxUnavailable"), "cannot be 0 when maxSurge is 0"))
+		}
+
+	} else {
+		allErrs = append(allErrs, ValidatePositiveIntOrPercent(rollingUpdate.MaxUnavailable, fldPath.Child("maxUnavailable"))...)
+		if getIntOrPercentValue(rollingUpdate.MaxUnavailable) == 0 {
+			// MaxUnavailable cannot be 0.
+			allErrs = append(allErrs, field.Invalid(fldPath.Child("maxUnavailable"), rollingUpdate.MaxUnavailable, "cannot be 0"))
+		}
+		// Validate that MaxUnavailable is not more than 100%.
+		allErrs = append(allErrs, IsNotMoreThan100Percent(rollingUpdate.MaxUnavailable, fldPath.Child("maxUnavailable"))...)
 	}
-	// Validate that MaxUnavailable is not more than 100%.
-	allErrs = append(allErrs, IsNotMoreThan100Percent(rollingUpdate.MaxUnavailable, fldPath.Child("maxUnavailable"))...)
 	return allErrs
 }