kubeadm: add ImagePullSerial field to v1beta4 NodeRegistationOptions

ImagePullSerial specifies if image pulling performed
by kubeadm must be done serially or in parallel.
Default: true

cmd/kubeadm/app/apis/kubeadm/fuzzer/fuzzer.go

@@ -22,6 +22,7 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	runtimeserializer "k8s.io/apimachinery/pkg/runtime/serializer"
+	"k8s.io/utils/ptr"
 
 	bootstraptokenv1 "k8s.io/kubernetes/cmd/kubeadm/app/apis/bootstraptoken/v1"
 	"k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
@@ -62,6 +63,7 @@ func fuzzInitConfiguration(obj *kubeadm.InitConfiguration, c fuzz.Continue) {
 	}
 	obj.SkipPhases = nil
 	obj.NodeRegistration.ImagePullPolicy = corev1.PullIfNotPresent
+	obj.NodeRegistration.ImagePullSerial = ptr.To(true)
 	obj.Patches = nil
 	obj.DryRun = false
 	kubeadm.SetDefaultTimeouts(&obj.Timeouts)
@@ -72,6 +74,7 @@ func fuzzNodeRegistration(obj *kubeadm.NodeRegistrationOptions, c fuzz.Continue)
 
 	// Pinning values for fields that get defaults if fuzz value is empty string or nil (thus making the round trip test fail)
 	obj.IgnorePreflightErrors = nil
+	obj.ImagePullSerial = ptr.To(true)
 }
 
 func fuzzClusterConfiguration(obj *kubeadm.ClusterConfiguration, c fuzz.Continue) {
@@ -132,6 +135,7 @@ func fuzzJoinConfiguration(obj *kubeadm.JoinConfiguration, c fuzz.Continue) {
 	}
 	obj.SkipPhases = nil
 	obj.NodeRegistration.ImagePullPolicy = corev1.PullIfNotPresent
+	obj.NodeRegistration.ImagePullSerial = ptr.To(true)
 	obj.Patches = nil
 	obj.DryRun = false
 	kubeadm.SetDefaultTimeouts(&obj.Timeouts)

cmd/kubeadm/app/apis/kubeadm/types.go

@@ -249,6 +249,9 @@ type NodeRegistrationOptions struct {
 	// The value of this field must be one of "Always", "IfNotPresent" or "Never".
 	// If this field is unset kubeadm will default it to "IfNotPresent", or pull the required images if not present on the host.
 	ImagePullPolicy v1.PullPolicy `json:"imagePullPolicy,omitempty"`
+
+	// ImagePullSerial specifies if image pulling performed by kubeadm must be done serially or in parallel.
+	ImagePullSerial *bool
 }
 
 // Networking contains elements describing cluster's networking configuration.

cmd/kubeadm/app/apis/kubeadm/v1beta3/conversion.go

@@ -20,6 +20,7 @@ import (
 	"sort"
 
 	"k8s.io/apimachinery/pkg/conversion"
+	"k8s.io/utils/ptr"
 
 	"k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
 )
@@ -98,6 +99,7 @@ func Convert_kubeadm_LocalEtcd_To_v1beta3_LocalEtcd(in *kubeadm.LocalEtcd, out *
 // Convert_v1beta3_NodeRegistrationOptions_To_kubeadm_NodeRegistrationOptions converts a public NodeRegistrationOptions to private NodeRegistrationOptions.
 func Convert_v1beta3_NodeRegistrationOptions_To_kubeadm_NodeRegistrationOptions(in *NodeRegistrationOptions, out *kubeadm.NodeRegistrationOptions, s conversion.Scope) error {
 	out.KubeletExtraArgs = convertToArgs(in.KubeletExtraArgs)
+	out.ImagePullSerial = ptr.To(true)
 	return autoConvert_v1beta3_NodeRegistrationOptions_To_kubeadm_NodeRegistrationOptions(in, out, s)
 }
 

cmd/kubeadm/app/apis/kubeadm/v1beta3/zz_generated.conversion.go

@@ -708,6 +708,7 @@ func autoConvert_kubeadm_NodeRegistrationOptions_To_v1beta3_NodeRegistrationOpti
 	// WARNING: in.KubeletExtraArgs requires manual conversion: inconvertible types ([]k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm.Arg vs map[string]string)
 	out.IgnorePreflightErrors = *(*[]string)(unsafe.Pointer(&in.IgnorePreflightErrors))
 	out.ImagePullPolicy = corev1.PullPolicy(in.ImagePullPolicy)
+	// WARNING: in.ImagePullSerial requires manual conversion: does not exist in peer-type
 	return nil
 }
 

cmd/kubeadm/app/apis/kubeadm/v1beta4/defaults.go

@@ -22,6 +22,7 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/utils/ptr"
 
 	bootstraptokenv1 "k8s.io/kubernetes/cmd/kubeadm/app/apis/bootstraptoken/v1"
 	"k8s.io/kubernetes/cmd/kubeadm/app/constants"
@@ -194,6 +195,9 @@ func SetDefaults_NodeRegistration(obj *NodeRegistrationOptions) {
 	if len(obj.ImagePullPolicy) == 0 {
 		obj.ImagePullPolicy = DefaultImagePullPolicy
 	}
+	if obj.ImagePullSerial == nil {
+		obj.ImagePullSerial = ptr.To(true)
+	}
 }
 
 // SetDefaults_ResetConfiguration assigns default values for the ResetConfiguration object

cmd/kubeadm/app/apis/kubeadm/v1beta4/doc.go

@@ -40,6 +40,8 @@ limitations under the License.
 //     during cluster creation will set the same fields to `false`.
 //   - Add a `Timeouts` structure to `InitConfiguration`, `JoinConfiguration` and `ResetConfiguration“
 //     that can be used to configure various timeouts.
+//   - Add the `NodeRegistration.ImagePullSerial` field in 'InitConfiguration` and `JoinConfiguration`, which
+//     can be used to control if kubeadm pulls images serially or in parallel.
 //
 // Migration from old kubeadm config versions
 //

cmd/kubeadm/app/apis/kubeadm/v1beta4/types.go

@@ -263,6 +263,11 @@ type NodeRegistrationOptions struct {
 	// If this field is unset kubeadm will default it to "IfNotPresent", or pull the required images if not present on the host.
 	// +optional
 	ImagePullPolicy corev1.PullPolicy `json:"imagePullPolicy,omitempty"`
+
+	// ImagePullSerial specifies if image pulling performed by kubeadm must be done serially or in parallel.
+	// Default: true
+	// +optional
+	ImagePullSerial *bool `json:"imagePullSerial,omitempty"`
 }
 
 // Networking contains elements describing cluster's networking configuration

cmd/kubeadm/app/apis/kubeadm/v1beta4/zz_generated.conversion.go

@@ -810,6 +810,7 @@ func autoConvert_v1beta4_NodeRegistrationOptions_To_kubeadm_NodeRegistrationOpti
 	out.KubeletExtraArgs = *(*[]kubeadm.Arg)(unsafe.Pointer(&in.KubeletExtraArgs))
 	out.IgnorePreflightErrors = *(*[]string)(unsafe.Pointer(&in.IgnorePreflightErrors))
 	out.ImagePullPolicy = v1.PullPolicy(in.ImagePullPolicy)
+	out.ImagePullSerial = (*bool)(unsafe.Pointer(in.ImagePullSerial))
 	return nil
 }
 
@@ -825,6 +826,7 @@ func autoConvert_kubeadm_NodeRegistrationOptions_To_v1beta4_NodeRegistrationOpti
 	out.KubeletExtraArgs = *(*[]Arg)(unsafe.Pointer(&in.KubeletExtraArgs))
 	out.IgnorePreflightErrors = *(*[]string)(unsafe.Pointer(&in.IgnorePreflightErrors))
 	out.ImagePullPolicy = v1.PullPolicy(in.ImagePullPolicy)
+	out.ImagePullSerial = (*bool)(unsafe.Pointer(in.ImagePullSerial))
 	return nil
 }
 

cmd/kubeadm/app/apis/kubeadm/v1beta4/zz_generated.deepcopy.go

@@ -518,6 +518,11 @@ func (in *NodeRegistrationOptions) DeepCopyInto(out *NodeRegistrationOptions) {
 		*out = make([]string, len(*in))
 		copy(*out, *in)
 	}
+	if in.ImagePullSerial != nil {
+		in, out := &in.ImagePullSerial, &out.ImagePullSerial
+		*out = new(bool)
+		**out = **in
+	}
 	return
 }
 

cmd/kubeadm/app/apis/kubeadm/zz_generated.deepcopy.go

@@ -558,6 +558,11 @@ func (in *NodeRegistrationOptions) DeepCopyInto(out *NodeRegistrationOptions) {
 		*out = make([]string, len(*in))
 		copy(*out, *in)
 	}
+	if in.ImagePullSerial != nil {
+		in, out := &in.ImagePullSerial, &out.ImagePullSerial
+		*out = new(bool)
+		**out = **in
+	}
 	return
 }
 

cmd/kubeadm/app/cmd/init_test.go

@@ -30,6 +30,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/utils/ptr"
 
 	bootstraptokenv1 "k8s.io/kubernetes/cmd/kubeadm/app/apis/bootstraptoken/v1"
 	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
@@ -134,6 +135,7 @@ func TestNewInitData(t *testing.T) {
 							CRISocket:             expectedCRISocket,
 							IgnorePreflightErrors: []string{"c", "d"},
 							ImagePullPolicy:       "IfNotPresent",
+							ImagePullSerial:       ptr.To(true),
 						},
 						LocalAPIEndpoint: kubeadmapi.APIEndpoint{
 							AdvertiseAddress: "1.2.3.4",

cmd/kubeadm/app/cmd/join_test.go

@@ -31,6 +31,7 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/klog/v2"
+	"k8s.io/utils/ptr"
 
 	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
 	kubeadmapiv1 "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta3"
@@ -221,6 +222,7 @@ func TestNewJoinData(t *testing.T) {
 							CRISocket:             expectedCRISocket,
 							IgnorePreflightErrors: []string{"c", "d"},
 							ImagePullPolicy:       "IfNotPresent",
+							ImagePullSerial:       ptr.To(true),
 							Taints:                []v1.Taint{{Key: "node-role.kubernetes.io/control-plane", Effect: "NoSchedule"}},
 						},
 						CACertPath: kubeadmapiv1.DefaultCACertPath,