kubeadm: Support custom env in control plane component

Signed-off-by: Dave Chen <dave.chen@arm.com>

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

@@ -150,6 +150,11 @@ type ControlPlaneComponent struct {
 
 	// ExtraVolumes is an extra set of host volumes, mounted to the control plane component.
 	ExtraVolumes []HostPathMount
+
+	// ExtraEnvs is an extra set of environment variables to pass to the control plane component.
+	// Environment variables passed using ExtraEnvs will override any existing environment variables, or *_proxy environment variables that kubeadm adds by default.
+	// +optional
+	ExtraEnvs []v1.EnvVar
 }
 
 // APIServer holds settings necessary for API server deployments in the cluster
@@ -262,6 +267,11 @@ type LocalEtcd struct {
 	// command line except without leading dash(es).
 	ExtraArgs map[string]string
 
+	// ExtraEnvs is an extra set of environment variables to pass to the control plane component.
+	// Environment variables passed using ExtraEnvs will override any existing environment variables, or *_proxy environment variables that kubeadm adds by default.
+	// +optional
+	ExtraEnvs []v1.EnvVar
+
 	// ServerCertSANs sets extra Subject Alternative Names for the etcd server signing cert.
 	ServerCertSANs []string
 	// PeerCertSANs sets extra Subject Alternative Names for the etcd peer signing cert.

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

@@ -17,6 +17,7 @@ limitations under the License.
 package v1beta3
 
 import (
+	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/conversion"
 
 	"k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
@@ -34,3 +35,23 @@ func Convert_v1beta3_InitConfiguration_To_kubeadm_InitConfiguration(in *InitConf
 	err = Convert_v1beta3_ClusterConfiguration_To_kubeadm_ClusterConfiguration(&ClusterConfiguration{}, &out.ClusterConfiguration, s)
 	return err
 }
+
+// Convert_v1beta3_ControlPlaneComponent_To_kubeadm_ControlPlaneComponent is required due to the missing ControlPlaneComponent.ExtraEnvs in v1beta3.
+func Convert_v1beta3_ControlPlaneComponent_To_kubeadm_ControlPlaneComponent(in *ControlPlaneComponent, out *kubeadm.ControlPlaneComponent, s conversion.Scope) error {
+	out.ExtraEnvs = []v1.EnvVar{}
+	return autoConvert_v1beta3_ControlPlaneComponent_To_kubeadm_ControlPlaneComponent(in, out, s)
+}
+
+func Convert_kubeadm_ControlPlaneComponent_To_v1beta3_ControlPlaneComponent(in *kubeadm.ControlPlaneComponent, out *ControlPlaneComponent, s conversion.Scope) error {
+	return autoConvert_kubeadm_ControlPlaneComponent_To_v1beta3_ControlPlaneComponent(in, out, s)
+}
+
+// Convert_v1beta3_LocalEtcd_To_kubeadm_LocalEtcd is required due to the missing LocalEtcd.ExtraEnvs in v1beta3.
+func Convert_v1beta3_LocalEtcd_To_kubeadm_LocalEtcd(in *LocalEtcd, out *kubeadm.LocalEtcd, s conversion.Scope) error {
+	out.ExtraEnvs = []v1.EnvVar{}
+	return autoConvert_v1beta3_LocalEtcd_To_kubeadm_LocalEtcd(in, out, s)
+}
+
+func Convert_kubeadm_LocalEtcd_To_v1beta3_LocalEtcd(in *kubeadm.LocalEtcd, out *LocalEtcd, s conversion.Scope) error {
+	return autoConvert_kubeadm_LocalEtcd_To_v1beta3_LocalEtcd(in, out, s)
+}

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

@@ -79,16 +79,6 @@ func RegisterConversions(s *runtime.Scheme) error {
 	}); err != nil {
 		return err
 	}
-	if err := s.AddGeneratedConversionFunc((*ControlPlaneComponent)(nil), (*kubeadm.ControlPlaneComponent)(nil), func(a, b interface{}, scope conversion.Scope) error {
-		return Convert_v1beta3_ControlPlaneComponent_To_kubeadm_ControlPlaneComponent(a.(*ControlPlaneComponent), b.(*kubeadm.ControlPlaneComponent), scope)
-	}); err != nil {
-		return err
-	}
-	if err := s.AddGeneratedConversionFunc((*kubeadm.ControlPlaneComponent)(nil), (*ControlPlaneComponent)(nil), func(a, b interface{}, scope conversion.Scope) error {
-		return Convert_kubeadm_ControlPlaneComponent_To_v1beta3_ControlPlaneComponent(a.(*kubeadm.ControlPlaneComponent), b.(*ControlPlaneComponent), scope)
-	}); err != nil {
-		return err
-	}
 	if err := s.AddGeneratedConversionFunc((*DNS)(nil), (*kubeadm.DNS)(nil), func(a, b interface{}, scope conversion.Scope) error {
 		return Convert_v1beta3_DNS_To_kubeadm_DNS(a.(*DNS), b.(*kubeadm.DNS), scope)
 	}); err != nil {
@@ -179,16 +169,6 @@ func RegisterConversions(s *runtime.Scheme) error {
 	}); err != nil {
 		return err
 	}
-	if err := s.AddGeneratedConversionFunc((*LocalEtcd)(nil), (*kubeadm.LocalEtcd)(nil), func(a, b interface{}, scope conversion.Scope) error {
-		return Convert_v1beta3_LocalEtcd_To_kubeadm_LocalEtcd(a.(*LocalEtcd), b.(*kubeadm.LocalEtcd), scope)
-	}); err != nil {
-		return err
-	}
-	if err := s.AddGeneratedConversionFunc((*kubeadm.LocalEtcd)(nil), (*LocalEtcd)(nil), func(a, b interface{}, scope conversion.Scope) error {
-		return Convert_kubeadm_LocalEtcd_To_v1beta3_LocalEtcd(a.(*kubeadm.LocalEtcd), b.(*LocalEtcd), scope)
-	}); err != nil {
-		return err
-	}
 	if err := s.AddGeneratedConversionFunc((*Networking)(nil), (*kubeadm.Networking)(nil), func(a, b interface{}, scope conversion.Scope) error {
 		return Convert_v1beta3_Networking_To_kubeadm_Networking(a.(*Networking), b.(*kubeadm.Networking), scope)
 	}); err != nil {
@@ -219,16 +199,36 @@ func RegisterConversions(s *runtime.Scheme) error {
 	}); err != nil {
 		return err
 	}
+	if err := s.AddConversionFunc((*kubeadm.ControlPlaneComponent)(nil), (*ControlPlaneComponent)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_kubeadm_ControlPlaneComponent_To_v1beta3_ControlPlaneComponent(a.(*kubeadm.ControlPlaneComponent), b.(*ControlPlaneComponent), scope)
+	}); err != nil {
+		return err
+	}
 	if err := s.AddConversionFunc((*kubeadm.InitConfiguration)(nil), (*InitConfiguration)(nil), func(a, b interface{}, scope conversion.Scope) error {
 		return Convert_kubeadm_InitConfiguration_To_v1beta3_InitConfiguration(a.(*kubeadm.InitConfiguration), b.(*InitConfiguration), scope)
 	}); err != nil {
 		return err
 	}
+	if err := s.AddConversionFunc((*kubeadm.LocalEtcd)(nil), (*LocalEtcd)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_kubeadm_LocalEtcd_To_v1beta3_LocalEtcd(a.(*kubeadm.LocalEtcd), b.(*LocalEtcd), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddConversionFunc((*ControlPlaneComponent)(nil), (*kubeadm.ControlPlaneComponent)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1beta3_ControlPlaneComponent_To_kubeadm_ControlPlaneComponent(a.(*ControlPlaneComponent), b.(*kubeadm.ControlPlaneComponent), scope)
+	}); err != nil {
+		return err
+	}
 	if err := s.AddConversionFunc((*InitConfiguration)(nil), (*kubeadm.InitConfiguration)(nil), func(a, b interface{}, scope conversion.Scope) error {
 		return Convert_v1beta3_InitConfiguration_To_kubeadm_InitConfiguration(a.(*InitConfiguration), b.(*kubeadm.InitConfiguration), scope)
 	}); err != nil {
 		return err
 	}
+	if err := s.AddConversionFunc((*LocalEtcd)(nil), (*kubeadm.LocalEtcd)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1beta3_LocalEtcd_To_kubeadm_LocalEtcd(a.(*LocalEtcd), b.(*kubeadm.LocalEtcd), scope)
+	}); err != nil {
+		return err
+	}
 	return nil
 }
 
@@ -383,22 +383,13 @@ func autoConvert_v1beta3_ControlPlaneComponent_To_kubeadm_ControlPlaneComponent(
 	return nil
 }
 
-// Convert_v1beta3_ControlPlaneComponent_To_kubeadm_ControlPlaneComponent is an autogenerated conversion function.
-func Convert_v1beta3_ControlPlaneComponent_To_kubeadm_ControlPlaneComponent(in *ControlPlaneComponent, out *kubeadm.ControlPlaneComponent, s conversion.Scope) error {
-	return autoConvert_v1beta3_ControlPlaneComponent_To_kubeadm_ControlPlaneComponent(in, out, s)
-}
-
 func autoConvert_kubeadm_ControlPlaneComponent_To_v1beta3_ControlPlaneComponent(in *kubeadm.ControlPlaneComponent, out *ControlPlaneComponent, s conversion.Scope) error {
 	out.ExtraArgs = *(*map[string]string)(unsafe.Pointer(&in.ExtraArgs))
 	out.ExtraVolumes = *(*[]HostPathMount)(unsafe.Pointer(&in.ExtraVolumes))
+	// WARNING: in.ExtraEnvs requires manual conversion: does not exist in peer-type
 	return nil
 }
 
-// Convert_kubeadm_ControlPlaneComponent_To_v1beta3_ControlPlaneComponent is an autogenerated conversion function.
-func Convert_kubeadm_ControlPlaneComponent_To_v1beta3_ControlPlaneComponent(in *kubeadm.ControlPlaneComponent, out *ControlPlaneComponent, s conversion.Scope) error {
-	return autoConvert_kubeadm_ControlPlaneComponent_To_v1beta3_ControlPlaneComponent(in, out, s)
-}
-
 func autoConvert_v1beta3_DNS_To_kubeadm_DNS(in *DNS, out *kubeadm.DNS, s conversion.Scope) error {
 	if err := Convert_v1beta3_ImageMeta_To_kubeadm_ImageMeta(&in.ImageMeta, &out.ImageMeta, s); err != nil {
 		return err
@@ -450,7 +441,15 @@ func Convert_kubeadm_Discovery_To_v1beta3_Discovery(in *kubeadm.Discovery, out *
 }
 
 func autoConvert_v1beta3_Etcd_To_kubeadm_Etcd(in *Etcd, out *kubeadm.Etcd, s conversion.Scope) error {
-	out.Local = (*kubeadm.LocalEtcd)(unsafe.Pointer(in.Local))
+	if in.Local != nil {
+		in, out := &in.Local, &out.Local
+		*out = new(kubeadm.LocalEtcd)
+		if err := Convert_v1beta3_LocalEtcd_To_kubeadm_LocalEtcd(*in, *out, s); err != nil {
+			return err
+		}
+	} else {
+		out.Local = nil
+	}
 	out.External = (*kubeadm.ExternalEtcd)(unsafe.Pointer(in.External))
 	return nil
 }
@@ -461,7 +460,15 @@ func Convert_v1beta3_Etcd_To_kubeadm_Etcd(in *Etcd, out *kubeadm.Etcd, s convers
 }
 
 func autoConvert_kubeadm_Etcd_To_v1beta3_Etcd(in *kubeadm.Etcd, out *Etcd, s conversion.Scope) error {
-	out.Local = (*LocalEtcd)(unsafe.Pointer(in.Local))
+	if in.Local != nil {
+		in, out := &in.Local, &out.Local
+		*out = new(LocalEtcd)
+		if err := Convert_kubeadm_LocalEtcd_To_v1beta3_LocalEtcd(*in, *out, s); err != nil {
+			return err
+		}
+	} else {
+		out.Local = nil
+	}
 	out.External = (*ExternalEtcd)(unsafe.Pointer(in.External))
 	return nil
 }
@@ -671,27 +678,18 @@ func autoConvert_v1beta3_LocalEtcd_To_kubeadm_LocalEtcd(in *LocalEtcd, out *kube
 	return nil
 }
 
-// Convert_v1beta3_LocalEtcd_To_kubeadm_LocalEtcd is an autogenerated conversion function.
-func Convert_v1beta3_LocalEtcd_To_kubeadm_LocalEtcd(in *LocalEtcd, out *kubeadm.LocalEtcd, s conversion.Scope) error {
-	return autoConvert_v1beta3_LocalEtcd_To_kubeadm_LocalEtcd(in, out, s)
-}
-
 func autoConvert_kubeadm_LocalEtcd_To_v1beta3_LocalEtcd(in *kubeadm.LocalEtcd, out *LocalEtcd, s conversion.Scope) error {
 	if err := Convert_kubeadm_ImageMeta_To_v1beta3_ImageMeta(&in.ImageMeta, &out.ImageMeta, s); err != nil {
 		return err
 	}
 	out.DataDir = in.DataDir
 	out.ExtraArgs = *(*map[string]string)(unsafe.Pointer(&in.ExtraArgs))
+	// WARNING: in.ExtraEnvs requires manual conversion: does not exist in peer-type
 	out.ServerCertSANs = *(*[]string)(unsafe.Pointer(&in.ServerCertSANs))
 	out.PeerCertSANs = *(*[]string)(unsafe.Pointer(&in.PeerCertSANs))
 	return nil
 }
 
-// Convert_kubeadm_LocalEtcd_To_v1beta3_LocalEtcd is an autogenerated conversion function.
-func Convert_kubeadm_LocalEtcd_To_v1beta3_LocalEtcd(in *kubeadm.LocalEtcd, out *LocalEtcd, s conversion.Scope) error {
-	return autoConvert_kubeadm_LocalEtcd_To_v1beta3_LocalEtcd(in, out, s)
-}
-
 func autoConvert_v1beta3_Networking_To_kubeadm_Networking(in *Networking, out *kubeadm.Networking, s conversion.Scope) error {
 	out.ServiceSubnet = in.ServiceSubnet
 	out.PodSubnet = in.PodSubnet

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

@@ -20,10 +20,13 @@ limitations under the License.
 // +k8s:conversion-gen=k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm
 
 // Package v1beta4 defines the v1beta4 version of the kubeadm configuration file format.
-// This version improves on the v1beta2 format by fixing some minor issues and adding a few new fields.
+// This version improves on the v1beta3 format by fixing some minor issues and adding a few new fields.
 //
 // A list of changes since v1beta3:
+//
 //   - TODO https://github.com/kubernetes/kubeadm/issues/2890
+//   - Support custom environment variables in control plane components under `ClusterConfiguration`.
+//     Use `APIServer.ExtraEnvs`, `ControllerManager.ExtraEnvs`, `Scheduler.ExtraEnvs`,  `Etcd.Local.ExtraEnvs`.
 //
 // Migration from old kubeadm config versions
 //
@@ -39,7 +42,7 @@ limitations under the License.
 // configuration options defined in the kubeadm config file are also available as command line flags, but only
 // the most common/simple use case are supported with this approach.
 //
-// A kubeadm config file could contain multiple configuration types separated using three dashes (“---”).
+// A kubeadm config file could contain multiple configuration types separated using three dashes ("---").
 //
 // kubeadm supports the following configuration types:
 //

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

@@ -150,6 +150,11 @@ type ControlPlaneComponent struct {
 	// ExtraVolumes is an extra set of host volumes, mounted to the control plane component.
 	// +optional
 	ExtraVolumes []HostPathMount `json:"extraVolumes,omitempty"`
+
+	// ExtraEnvs is an extra set of environment variables to pass to the control plane component.
+	// Environment variables passed using ExtraEnvs will override any existing environment variables, or *_proxy environment variables that kubeadm adds by default.
+	// +optional
+	ExtraEnvs []corev1.EnvVar `json:"extraEnvs,omitempty"`
 }
 
 // APIServer holds settings necessary for API server deployments in the cluster
@@ -282,6 +287,11 @@ type LocalEtcd struct {
 	// +optional
 	ExtraArgs map[string]string `json:"extraArgs,omitempty"`
 
+	// ExtraEnvs is an extra set of environment variables to pass to the control plane component.
+	// Environment variables passed using ExtraEnvs will override any existing environment variables, or *_proxy environment variables that kubeadm adds by default.
+	// +optional
+	ExtraEnvs []corev1.EnvVar `json:"extraEnvs,omitempty"`
+
 	// ServerCertSANs sets extra Subject Alternative Names for the etcd server signing cert.
 	// +optional
 	ServerCertSANs []string `json:"serverCertSANs,omitempty"`

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

@@ -380,6 +380,7 @@ func Convert_kubeadm_ClusterConfiguration_To_v1beta4_ClusterConfiguration(in *ku
 func autoConvert_v1beta4_ControlPlaneComponent_To_kubeadm_ControlPlaneComponent(in *ControlPlaneComponent, out *kubeadm.ControlPlaneComponent, s conversion.Scope) error {
 	out.ExtraArgs = *(*map[string]string)(unsafe.Pointer(&in.ExtraArgs))
 	out.ExtraVolumes = *(*[]kubeadm.HostPathMount)(unsafe.Pointer(&in.ExtraVolumes))
+	out.ExtraEnvs = *(*[]corev1.EnvVar)(unsafe.Pointer(&in.ExtraEnvs))
 	return nil
 }
 
@@ -391,6 +392,7 @@ func Convert_v1beta4_ControlPlaneComponent_To_kubeadm_ControlPlaneComponent(in *
 func autoConvert_kubeadm_ControlPlaneComponent_To_v1beta4_ControlPlaneComponent(in *kubeadm.ControlPlaneComponent, out *ControlPlaneComponent, s conversion.Scope) error {
 	out.ExtraArgs = *(*map[string]string)(unsafe.Pointer(&in.ExtraArgs))
 	out.ExtraVolumes = *(*[]HostPathMount)(unsafe.Pointer(&in.ExtraVolumes))
+	out.ExtraEnvs = *(*[]corev1.EnvVar)(unsafe.Pointer(&in.ExtraEnvs))
 	return nil
 }
 
@@ -666,6 +668,7 @@ func autoConvert_v1beta4_LocalEtcd_To_kubeadm_LocalEtcd(in *LocalEtcd, out *kube
 	}
 	out.DataDir = in.DataDir
 	out.ExtraArgs = *(*map[string]string)(unsafe.Pointer(&in.ExtraArgs))
+	out.ExtraEnvs = *(*[]corev1.EnvVar)(unsafe.Pointer(&in.ExtraEnvs))
 	out.ServerCertSANs = *(*[]string)(unsafe.Pointer(&in.ServerCertSANs))
 	out.PeerCertSANs = *(*[]string)(unsafe.Pointer(&in.PeerCertSANs))
 	return nil
@@ -682,6 +685,7 @@ func autoConvert_kubeadm_LocalEtcd_To_v1beta4_LocalEtcd(in *kubeadm.LocalEtcd, o
 	}
 	out.DataDir = in.DataDir
 	out.ExtraArgs = *(*map[string]string)(unsafe.Pointer(&in.ExtraArgs))
+	out.ExtraEnvs = *(*[]corev1.EnvVar)(unsafe.Pointer(&in.ExtraEnvs))
 	out.ServerCertSANs = *(*[]string)(unsafe.Pointer(&in.ServerCertSANs))
 	out.PeerCertSANs = *(*[]string)(unsafe.Pointer(&in.PeerCertSANs))
 	return nil

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

@@ -145,6 +145,13 @@ func (in *ControlPlaneComponent) DeepCopyInto(out *ControlPlaneComponent) {
 		*out = make([]HostPathMount, len(*in))
 		copy(*out, *in)
 	}
+	if in.ExtraEnvs != nil {
+		in, out := &in.ExtraEnvs, &out.ExtraEnvs
+		*out = make([]corev1.EnvVar, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
 	return
 }
 
@@ -415,6 +422,13 @@ func (in *LocalEtcd) DeepCopyInto(out *LocalEtcd) {
 			(*out)[key] = val
 		}
 	}
+	if in.ExtraEnvs != nil {
+		in, out := &in.ExtraEnvs, &out.ExtraEnvs
+		*out = make([]corev1.EnvVar, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
 	if in.ServerCertSANs != nil {
 		in, out := &in.ServerCertSANs, &out.ServerCertSANs
 		*out = make([]string, len(*in))

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

@@ -23,6 +23,7 @@ package v1beta4
 
 import (
 	runtime "k8s.io/apimachinery/pkg/runtime"
+	v1 "k8s.io/kubernetes/pkg/apis/core/v1"
 )
 
 // RegisterDefaults adds defaulters functions to the given scheme.
@@ -37,7 +38,41 @@ func RegisterDefaults(scheme *runtime.Scheme) error {
 
 func SetObjectDefaults_ClusterConfiguration(in *ClusterConfiguration) {
 	SetDefaults_ClusterConfiguration(in)
+	if in.Etcd.Local != nil {
+		for i := range in.Etcd.Local.ExtraEnvs {
+			a := &in.Etcd.Local.ExtraEnvs[i]
+			if a.ValueFrom != nil {
+				if a.ValueFrom.FieldRef != nil {
+					v1.SetDefaults_ObjectFieldSelector(a.ValueFrom.FieldRef)
+				}
+			}
+		}
+	}
 	SetDefaults_APIServer(&in.APIServer)
+	for i := range in.APIServer.ControlPlaneComponent.ExtraEnvs {
+		a := &in.APIServer.ControlPlaneComponent.ExtraEnvs[i]
+		if a.ValueFrom != nil {
+			if a.ValueFrom.FieldRef != nil {
+				v1.SetDefaults_ObjectFieldSelector(a.ValueFrom.FieldRef)
+			}
+		}
+	}
+	for i := range in.ControllerManager.ExtraEnvs {
+		a := &in.ControllerManager.ExtraEnvs[i]
+		if a.ValueFrom != nil {
+			if a.ValueFrom.FieldRef != nil {
+				v1.SetDefaults_ObjectFieldSelector(a.ValueFrom.FieldRef)
+			}
+		}
+	}
+	for i := range in.Scheduler.ExtraEnvs {
+		a := &in.Scheduler.ExtraEnvs[i]
+		if a.ValueFrom != nil {
+			if a.ValueFrom.FieldRef != nil {
+				v1.SetDefaults_ObjectFieldSelector(a.ValueFrom.FieldRef)
+			}
+		}
+	}
 }
 
 func SetObjectDefaults_InitConfiguration(in *InitConfiguration) {

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

@@ -174,6 +174,13 @@ func (in *ControlPlaneComponent) DeepCopyInto(out *ControlPlaneComponent) {
 		*out = make([]HostPathMount, len(*in))
 		copy(*out, *in)
 	}
+	if in.ExtraEnvs != nil {
+		in, out := &in.ExtraEnvs, &out.ExtraEnvs
+		*out = make([]corev1.EnvVar, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
 	return
 }
 
@@ -445,6 +452,13 @@ func (in *LocalEtcd) DeepCopyInto(out *LocalEtcd) {
 			(*out)[key] = val
 		}
 	}
+	if in.ExtraEnvs != nil {
+		in, out := &in.ExtraEnvs, &out.ExtraEnvs
+		*out = make([]corev1.EnvVar, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
 	if in.ServerCertSANs != nil {
 		in, out := &in.ServerCertSANs, &out.ServerCertSANs
 		*out = make([]string, len(*in))

cmd/kubeadm/app/cmd/upgrade/diff.go

@@ -148,7 +148,7 @@ func runDiff(flags *diffFlags, args []string) error {
 
 	cfg.ClusterConfiguration.KubernetesVersion = flags.newK8sVersionStr
 
-	specs := controlplane.GetStaticPodSpecs(&cfg.ClusterConfiguration, &cfg.LocalAPIEndpoint)
+	specs := controlplane.GetStaticPodSpecs(&cfg.ClusterConfiguration, &cfg.LocalAPIEndpoint, nil)
 	for spec, pod := range specs {
 		var path string
 		switch spec {

cmd/kubeadm/app/phases/controlplane/manifests.go

@@ -48,9 +48,12 @@ func CreateInitStaticPodManifestFiles(manifestDir, patchesDir string, cfg *kubea
 
 // GetStaticPodSpecs returns all staticPodSpecs actualized to the context of the current configuration
 // NB. this method holds the information about how kubeadm creates static pod manifests.
-func GetStaticPodSpecs(cfg *kubeadmapi.ClusterConfiguration, endpoint *kubeadmapi.APIEndpoint) map[string]v1.Pod {
+func GetStaticPodSpecs(cfg *kubeadmapi.ClusterConfiguration, endpoint *kubeadmapi.APIEndpoint, proxyEnvs []v1.EnvVar) map[string]v1.Pod {
 	// Get the required hostpath mounts
 	mounts := getHostPathVolumesForTheControlPlane(cfg)
+	if proxyEnvs == nil {
+		proxyEnvs = kubeadmutil.GetProxyEnvVars()
+	}
 
 	// Prepare static pod specs
 	staticPodSpecs := map[string]v1.Pod{
@@ -64,7 +67,7 @@ func GetStaticPodSpecs(cfg *kubeadmapi.ClusterConfiguration, endpoint *kubeadmap
 			ReadinessProbe:  staticpodutil.ReadinessProbe(staticpodutil.GetAPIServerProbeAddress(endpoint), "/readyz", int(endpoint.BindPort), v1.URISchemeHTTPS),
 			StartupProbe:    staticpodutil.StartupProbe(staticpodutil.GetAPIServerProbeAddress(endpoint), "/livez", int(endpoint.BindPort), v1.URISchemeHTTPS, cfg.APIServer.TimeoutForControlPlane),
 			Resources:       staticpodutil.ComponentResources("250m"),
-			Env:             kubeadmutil.GetProxyEnvVars(),
+			Env:             kubeadmutil.MergeEnv(proxyEnvs, cfg.APIServer.ExtraEnvs),
 		}, mounts.GetVolumes(kubeadmconstants.KubeAPIServer),
 			map[string]string{kubeadmconstants.KubeAPIServerAdvertiseAddressEndpointAnnotationKey: endpoint.String()}),
 		kubeadmconstants.KubeControllerManager: staticpodutil.ComponentPod(v1.Container{
@@ -76,7 +79,7 @@ func GetStaticPodSpecs(cfg *kubeadmapi.ClusterConfiguration, endpoint *kubeadmap
 			LivenessProbe:   staticpodutil.LivenessProbe(staticpodutil.GetControllerManagerProbeAddress(cfg), "/healthz", kubeadmconstants.KubeControllerManagerPort, v1.URISchemeHTTPS),
 			StartupProbe:    staticpodutil.StartupProbe(staticpodutil.GetControllerManagerProbeAddress(cfg), "/healthz", kubeadmconstants.KubeControllerManagerPort, v1.URISchemeHTTPS, cfg.APIServer.TimeoutForControlPlane),
 			Resources:       staticpodutil.ComponentResources("200m"),
-			Env:             kubeadmutil.GetProxyEnvVars(),
+			Env:             kubeadmutil.MergeEnv(proxyEnvs, cfg.ControllerManager.ExtraEnvs),
 		}, mounts.GetVolumes(kubeadmconstants.KubeControllerManager), nil),
 		kubeadmconstants.KubeScheduler: staticpodutil.ComponentPod(v1.Container{
 			Name:            kubeadmconstants.KubeScheduler,
@@ -87,7 +90,7 @@ func GetStaticPodSpecs(cfg *kubeadmapi.ClusterConfiguration, endpoint *kubeadmap
 			LivenessProbe:   staticpodutil.LivenessProbe(staticpodutil.GetSchedulerProbeAddress(cfg), "/healthz", kubeadmconstants.KubeSchedulerPort, v1.URISchemeHTTPS),
 			StartupProbe:    staticpodutil.StartupProbe(staticpodutil.GetSchedulerProbeAddress(cfg), "/healthz", kubeadmconstants.KubeSchedulerPort, v1.URISchemeHTTPS, cfg.APIServer.TimeoutForControlPlane),
 			Resources:       staticpodutil.ComponentResources("100m"),
-			Env:             kubeadmutil.GetProxyEnvVars(),
+			Env:             kubeadmutil.MergeEnv(proxyEnvs, cfg.Scheduler.ExtraEnvs),
 		}, mounts.GetVolumes(kubeadmconstants.KubeScheduler), nil),
 	}
 	return staticPodSpecs
@@ -97,7 +100,7 @@ func GetStaticPodSpecs(cfg *kubeadmapi.ClusterConfiguration, endpoint *kubeadmap
 func CreateStaticPodFiles(manifestDir, patchesDir string, cfg *kubeadmapi.ClusterConfiguration, endpoint *kubeadmapi.APIEndpoint, isDryRun bool, componentNames ...string) error {
 	// gets the StaticPodSpecs, actualized for the current ClusterConfiguration
 	klog.V(1).Infoln("[control-plane] getting StaticPodSpecs")
-	specs := GetStaticPodSpecs(cfg, endpoint)
+	specs := GetStaticPodSpecs(cfg, endpoint, nil)
 
 	var usersAndGroups *users.UsersAndGroups
 	var err error

cmd/kubeadm/app/phases/controlplane/manifests_test.go

@@ -30,6 +30,7 @@ import (
 
 	"github.com/lithammer/dedent"
 
+	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/util/sets"
 
 	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
@@ -51,14 +52,18 @@ func TestGetStaticPodSpecs(t *testing.T) {
 	// Creates a Cluster Configuration
 	cfg := &kubeadmapi.ClusterConfiguration{
 		KubernetesVersion: "v1.9.0",
+		Scheduler: kubeadmapi.ControlPlaneComponent{ExtraEnvs: []v1.EnvVar{
+			{Name: "Foo", Value: "Bar"},
+		}},
 	}
 
 	// Executes GetStaticPodSpecs
-	specs := GetStaticPodSpecs(cfg, &kubeadmapi.APIEndpoint{})
+	specs := GetStaticPodSpecs(cfg, &kubeadmapi.APIEndpoint{}, []v1.EnvVar{})
 
 	var tests = []struct {
 		name          string
 		staticPodName string
+		env           []v1.EnvVar
 	}{
 		{
 			name:          "KubeAPIServer",
@@ -71,6 +76,7 @@ func TestGetStaticPodSpecs(t *testing.T) {
 		{
 			name:          "KubeScheduler",
 			staticPodName: kubeadmconstants.KubeScheduler,
+			env:           []v1.EnvVar{{Name: "Foo", Value: "Bar"}},
 		},
 	}
 
@@ -78,12 +84,15 @@ func TestGetStaticPodSpecs(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			// assert the spec for the staticPodName exists
 			if spec, ok := specs[tc.staticPodName]; ok {
-
 				// Assert each specs refers to the right pod
 				if spec.Spec.Containers[0].Name != tc.staticPodName {
 					t.Errorf("getKubeConfigSpecs spec for %s contains pod %s, expects %s", tc.staticPodName, spec.Spec.Containers[0].Name, tc.staticPodName)
 				}
-
+				if tc.env != nil {
+					if !reflect.DeepEqual(spec.Spec.Containers[0].Env, tc.env) {
+						t.Errorf("expected env: %v, got: %v", tc.env, spec.Spec.Containers[0].Env)
+					}
+				}
 			} else {
 				t.Errorf("getStaticPodSpecs didn't create spec for %s ", tc.staticPodName)
 			}

cmd/kubeadm/app/phases/etcd/local.go

@@ -224,6 +224,7 @@ func GetEtcdPodSpec(cfg *kubeadmapi.ClusterConfiguration, endpoint *kubeadmapi.A
 			},
 			LivenessProbe: staticpodutil.LivenessProbe(probeHostname, "/health?exclude=NOSPACE&serializable=true", probePort, probeScheme),
 			StartupProbe:  staticpodutil.StartupProbe(probeHostname, "/health?serializable=false", probePort, probeScheme, cfg.APIServer.TimeoutForControlPlane),
+			Env:           cfg.Etcd.Local.ExtraEnvs,
 		},
 		etcdMounts,
 		// etcd will listen on the advertise address of the API server, in a different port (2379)

cmd/kubeadm/app/phases/etcd/local_test.go

@@ -29,6 +29,7 @@ import (
 
 	"github.com/lithammer/dedent"
 
+	v1 "k8s.io/api/core/v1"
 	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
 	kubeadmconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
 	etcdutil "k8s.io/kubernetes/cmd/kubeadm/app/util/etcd"
@@ -43,6 +44,9 @@ func TestGetEtcdPodSpec(t *testing.T) {
 		Etcd: kubeadmapi.Etcd{
 			Local: &kubeadmapi.LocalEtcd{
 				DataDir: "/var/lib/etcd",
+				ExtraEnvs: []v1.EnvVar{
+					{Name: "Foo", Value: "Bar"},
+				},
 			},
 		},
 	}
@@ -55,6 +59,10 @@ func TestGetEtcdPodSpec(t *testing.T) {
 	if spec.Spec.Containers[0].Name != kubeadmconstants.Etcd {
 		t.Errorf("getKubeConfigSpecs spec for etcd contains pod %s, expects %s", spec.Spec.Containers[0].Name, kubeadmconstants.Etcd)
 	}
+	env := []v1.EnvVar{{Name: "Foo", Value: "Bar"}}
+	if !reflect.DeepEqual(spec.Spec.Containers[0].Env, env) {
+		t.Errorf("expected env: %v, got: %v", env, spec.Spec.Containers[0].Env)
+	}
 }
 
 func TestCreateLocalEtcdStaticPodManifestFile(t *testing.T) {

cmd/kubeadm/app/util/env.go

@@ -41,3 +41,18 @@ func GetProxyEnvVars() []v1.EnvVar {
 	}
 	return envs
 }
+
+// MergeEnv merges values of environment variable slices. The values defined in later slices overwrite values in previous ones.
+func MergeEnv(envList ...[]v1.EnvVar) []v1.EnvVar {
+	m := make(map[string]v1.EnvVar)
+	merged := []v1.EnvVar{}
+	for _, envs := range envList {
+		for _, env := range envs {
+			m[env.Name] = env
+		}
+	}
+	for _, v := range m {
+		merged = append(merged, v)
+	}
+	return merged
+}

cmd/kubeadm/app/util/env_test.go

@@ -0,0 +1,76 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package util
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	v1 "k8s.io/api/core/v1"
+)
+
+func TestMergeEnv(t *testing.T) {
+	baseEnv := []v1.EnvVar{}
+	extraEnv := []v1.EnvVar{}
+	MergeEnv(append(baseEnv, extraEnv...))
+	var tests = []struct {
+		name      string
+		proxyEnv  []v1.EnvVar
+		extraEnv  []v1.EnvVar
+		mergedEnv []v1.EnvVar
+	}{
+		{
+			name: "normal case without duplicated env",
+			proxyEnv: []v1.EnvVar{
+				{Name: "Foo1", Value: "Bar1"},
+				{Name: "Foo2", Value: "Bar2"},
+			},
+			extraEnv: []v1.EnvVar{
+				{Name: "Foo3", Value: "Bar3"},
+			},
+			mergedEnv: []v1.EnvVar{
+				{Name: "Foo1", Value: "Bar1"},
+				{Name: "Foo2", Value: "Bar2"},
+				{Name: "Foo3", Value: "Bar3"},
+			},
+		},
+		{
+			name: "extraEnv env take precedence over the proxyEnv",
+			proxyEnv: []v1.EnvVar{
+				{Name: "Foo1", Value: "Bar1"},
+				{Name: "Foo2", Value: "Bar2"},
+			},
+			extraEnv: []v1.EnvVar{
+				{Name: "Foo2", Value: "Bar3"},
+			},
+			mergedEnv: []v1.EnvVar{
+				{Name: "Foo1", Value: "Bar1"},
+				{Name: "Foo2", Value: "Bar3"},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			envs := MergeEnv(test.proxyEnv, test.extraEnv)
+			if !assert.ElementsMatch(t, envs, test.mergedEnv) {
+				t.Errorf("expected env: %v, got: %v", test.mergedEnv, envs)
+			}
+		})
+	}
+}