Kubeadm config refactor JoinControlPlane

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

@@ -290,12 +290,15 @@ type JoinConfiguration struct {
 	// Discovery specifies the options for the kubelet to use during the TLS Bootstrap process
 	Discovery Discovery
 
-	// ControlPlane flag specifies that the joining node should host an additional
-	// control plane instance.
-	ControlPlane bool
+	// ControlPlane defines the additional control plane instance to be deployed on the joining node.
+	// If nil, no additional control plane instance will be deployed.
+	ControlPlane *JoinControlPlane
+}
 
-	// APIEndpoint represents the endpoint of the instance of the API server eventually to be deployed on this node.
-	APIEndpoint APIEndpoint
+// JoinControlPlane contains elements describing an additional control plane instance to be deployed on the joining node.
+type JoinControlPlane struct {
+	// LocalAPIEndpoint represents the endpoint of the API server instance to be deployed on this node.
+	LocalAPIEndpoint APIEndpoint
 }
 
 // Discovery specifies the options for the kubelet to use during the TLS Bootstrap process

cmd/kubeadm/app/apis/kubeadm/v1alpha3/conversion.go

@@ -81,6 +81,13 @@ func Convert_v1alpha3_JoinConfiguration_To_kubeadm_JoinConfiguration(in *JoinCon
 		}
 	}
 
+	if in.ControlPlane == true {
+		out.ControlPlane = &kubeadm.JoinControlPlane{}
+		if err := autoConvert_v1alpha3_APIEndpoint_To_kubeadm_APIEndpoint(&in.APIEndpoint, &out.ControlPlane.LocalAPIEndpoint, s); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 
@@ -102,6 +109,13 @@ func Convert_kubeadm_JoinConfiguration_To_v1alpha3_JoinConfiguration(in *kubeadm
 		out.DiscoveryFile = in.Discovery.File.KubeConfigPath
 	}
 
+	if in.ControlPlane != nil {
+		out.ControlPlane = true
+		if err := autoConvert_kubeadm_APIEndpoint_To_v1alpha3_APIEndpoint(&in.ControlPlane.LocalAPIEndpoint, &out.APIEndpoint, s); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 

cmd/kubeadm/app/apis/kubeadm/v1beta1/defaults.go

@@ -132,7 +132,7 @@ func SetDefaults_JoinConfiguration(obj *JoinConfiguration) {
 	}
 
 	SetDefaults_NodeRegistrationOptions(&obj.NodeRegistration)
-	SetDefaults_APIEndpoint(&obj.APIEndpoint)
+	SetDefaults_JoinControlPlane(obj.ControlPlane)
 	SetDefaults_Discovery(&obj.Discovery)
 }
 
@@ -142,6 +142,12 @@ func SetDefaults_NodeRegistrationOptions(obj *NodeRegistrationOptions) {
 	}
 }
 
+func SetDefaults_JoinControlPlane(obj *JoinControlPlane) {
+	if obj != nil {
+		SetDefaults_APIEndpoint(&obj.LocalAPIEndpoint)
+	}
+}
+
 // SetDefaults_Discovery assigns default values for the discovery process
 func SetDefaults_Discovery(obj *Discovery) {
 	if len(obj.TLSBootstrapToken) == 0 && obj.BootstrapToken != nil {

cmd/kubeadm/app/apis/kubeadm/v1beta1/types.go

@@ -255,7 +255,6 @@ type ExternalEtcd struct {
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
 
 // JoinConfiguration contains elements describing a particular node.
-// TODO: This struct should be replaced by dynamic kubelet configuration.
 type JoinConfiguration struct {
 	metav1.TypeMeta `json:",inline"`
 
@@ -270,12 +269,15 @@ type JoinConfiguration struct {
 	// Discovery specifies the options for the kubelet to use during the TLS Bootstrap process
 	Discovery Discovery `json:"discovery"`
 
-	// ControlPlane flag specifies that the joining node should host an additional
-	// control plane instance.
-	ControlPlane bool `json:"controlPlane,omitempty"`
+	// ControlPlane defines the additional control plane instance to be deployed on the joining node.
+	// If nil, no additional control plane instance will be deployed.
+	ControlPlane *JoinControlPlane `json:"controlPlane,omitempty"`
+}
 
-	// APIEndpoint represents the endpoint of the instance of the API server eventually to be deployed on this node.
-	APIEndpoint APIEndpoint `json:"apiEndpoint,omitempty"`
+// JoinControlPlane contains elements describing an additional control plane instance to be deployed on the joining node.
+type JoinControlPlane struct {
+	// LocalAPIEndpoint represents the endpoint of the API server instance to be deployed on this node.
+	LocalAPIEndpoint APIEndpoint `json:"localAPIEndpoint,omitempty"`
 }
 
 // Discovery specifies the options for the kubelet to use during the TLS Bootstrap process

cmd/kubeadm/app/apis/kubeadm/validation/validation.go

@@ -27,7 +27,6 @@ import (
 
 	"github.com/pkg/errors"
 	"github.com/spf13/pflag"
-
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/validation"
 	"k8s.io/apimachinery/pkg/util/validation/field"
@@ -78,14 +77,23 @@ func ValidateJoinConfiguration(c *kubeadm.JoinConfiguration) field.ErrorList {
 	allErrs := field.ErrorList{}
 	allErrs = append(allErrs, ValidateDiscovery(&c.Discovery, field.NewPath("discovery"))...)
 	allErrs = append(allErrs, ValidateNodeRegistrationOptions(&c.NodeRegistration, field.NewPath("nodeRegistration"))...)
-	allErrs = append(allErrs, ValidateAPIEndpoint(&c.APIEndpoint, field.NewPath("apiEndpoint"))...)
+	allErrs = append(allErrs, ValidateJoinControlPlane(c.ControlPlane, field.NewPath("controlPlane"))...)
 
 	if !filepath.IsAbs(c.CACertPath) || !strings.HasSuffix(c.CACertPath, ".crt") {
 		allErrs = append(allErrs, field.Invalid(field.NewPath("caCertPath"), c.CACertPath, "the ca certificate path must be an absolute path"))
 	}
 	return allErrs
 }
 
+// ValidateJoinControlPlane validates joining control plane configuration and collects all encountered errors
+func ValidateJoinControlPlane(c *kubeadm.JoinControlPlane, fldPath *field.Path) field.ErrorList {
+	allErrs := field.ErrorList{}
+	if c != nil {
+		allErrs = append(allErrs, ValidateAPIEndpoint(&c.LocalAPIEndpoint, fldPath.Child("localAPIEndpoint"))...)
+	}
+	return allErrs
+}
+
 // ValidateNodeRegistrationOptions validates the NodeRegistrationOptions object
 func ValidateNodeRegistrationOptions(nro *kubeadm.NodeRegistrationOptions, fldPath *field.Path) field.ErrorList {
 	allErrs := field.ErrorList{}

cmd/kubeadm/app/apis/kubeadm/validation/validation_test.go

@@ -23,7 +23,6 @@ import (
 	"time"
 
 	"github.com/spf13/pflag"
-
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/validation/field"
 	"k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
@@ -541,6 +540,84 @@ func TestValidateJoinConfiguration(t *testing.T) {
 				},
 			},
 		}, false},
+		{&kubeadm.JoinConfiguration{ // Pass without JoinControlPlane
+			CACertPath: "/some/cert.crt",
+			Discovery: kubeadm.Discovery{
+				BootstrapToken: &kubeadm.BootstrapTokenDiscovery{
+					Token:             "abcdef.1234567890123456",
+					APIServerEndpoint: "1.2.3.4:6443",
+					CACertHashes:      []string{"aaaa"},
+				},
+				TLSBootstrapToken: "abcdef.1234567890123456",
+			},
+			NodeRegistration: kubeadm.NodeRegistrationOptions{
+				Name:      "aaa",
+				CRISocket: "/var/run/dockershim.sock",
+			},
+		}, true},
+		{&kubeadm.JoinConfiguration{ // Pass with JoinControlPlane
+			CACertPath: "/some/cert.crt",
+			Discovery: kubeadm.Discovery{
+				BootstrapToken: &kubeadm.BootstrapTokenDiscovery{
+					Token:             "abcdef.1234567890123456",
+					APIServerEndpoint: "1.2.3.4:6443",
+					CACertHashes:      []string{"aaaa"},
+				},
+				TLSBootstrapToken: "abcdef.1234567890123456",
+			},
+			NodeRegistration: kubeadm.NodeRegistrationOptions{
+				Name:      "aaa",
+				CRISocket: "/var/run/dockershim.sock",
+			},
+			ControlPlane: &kubeadm.JoinControlPlane{
+				LocalAPIEndpoint: kubeadm.APIEndpoint{
+					AdvertiseAddress: "1.2.3.4",
+					BindPort:         1234,
+				},
+			},
+		}, true},
+		{&kubeadm.JoinConfiguration{ // Fail JoinControlPlane.AdvertiseAddress validation
+			CACertPath: "/some/cert.crt",
+			Discovery: kubeadm.Discovery{
+				BootstrapToken: &kubeadm.BootstrapTokenDiscovery{
+					Token:             "abcdef.1234567890123456",
+					APIServerEndpoint: "1.2.3.4:6443",
+					CACertHashes:      []string{"aaaa"},
+				},
+				TLSBootstrapToken: "abcdef.1234567890123456",
+			},
+			NodeRegistration: kubeadm.NodeRegistrationOptions{
+				Name:      "aaa",
+				CRISocket: "/var/run/dockershim.sock",
+			},
+			ControlPlane: &kubeadm.JoinControlPlane{
+				LocalAPIEndpoint: kubeadm.APIEndpoint{
+					AdvertiseAddress: "aaa",
+					BindPort:         1234,
+				},
+			},
+		}, false},
+		{&kubeadm.JoinConfiguration{ // Fail JoinControlPlane.BindPort validation
+			CACertPath: "/some/cert.crt",
+			Discovery: kubeadm.Discovery{
+				BootstrapToken: &kubeadm.BootstrapTokenDiscovery{
+					Token:             "abcdef.1234567890123456",
+					APIServerEndpoint: "1.2.3.4:6443",
+					CACertHashes:      []string{"aaaa"},
+				},
+				TLSBootstrapToken: "abcdef.1234567890123456",
+			},
+			NodeRegistration: kubeadm.NodeRegistrationOptions{
+				Name:      "aaa",
+				CRISocket: "/var/run/dockershim.sock",
+			},
+			ControlPlane: &kubeadm.JoinControlPlane{
+				LocalAPIEndpoint: kubeadm.APIEndpoint{
+					AdvertiseAddress: "1.2.3.4",
+					BindPort:         -1,
+				},
+			},
+		}, false},
 	}
 	for _, rt := range tests {
 		actual := ValidateJoinConfiguration(rt.s)