cmd/k8s-operator: Allow specifying cluster ips for nameservers (#16477)

This commit modifies the kubernetes operator's `DNSConfig` resource
with the addition of a new field at `nameserver.service.clusterIP`.

This field allows users to specify a static in-cluster IP address of
the nameserver when deployed.

Fixes #14305

Signed-off-by: David Bond <davidsbond93@gmail.com>

k8s-operator/api.md

@@ -422,6 +422,7 @@ _Appears in:_
 | Field | Description | Default | Validation |
 | --- | --- | --- | --- |
 | `image` _[NameserverImage](#nameserverimage)_ | Nameserver image. Defaults to tailscale/k8s-nameserver:unstable. |  |  |
+| `service` _[NameserverService](#nameserverservice)_ | Service configuration. |  |  |
 
 
 #### NameserverImage
@@ -441,6 +442,22 @@ _Appears in:_
 | `tag` _string_ | Tag defaults to unstable. |  |  |
 
 
+#### NameserverService
+
+
+
+
+
+
+
+_Appears in:_
+- [Nameserver](#nameserver)
+
+| Field | Description | Default | Validation |
+| --- | --- | --- | --- |
+| `clusterIP` _string_ | ClusterIP sets the static IP of the service used by the nameserver. |  |  |
+
+
 #### NameserverStatus
 
 
@@ -454,7 +471,7 @@ _Appears in:_
 
 | Field | Description | Default | Validation |
 | --- | --- | --- | --- |
-| `ip` _string_ | IP is the ClusterIP of the Service fronting the deployed ts.net nameserver.<br />Currently you must manually update your cluster DNS config to add<br />this address as a stub nameserver for ts.net for cluster workloads to be<br />able to resolve MagicDNS names associated with egress or Ingress<br />proxies.<br />The IP address will change if you delete and recreate the DNSConfig. |  |  |
+| `ip` _string_ | IP is the ClusterIP of the Service fronting the deployed ts.net nameserver.<br />Currently, you must manually update your cluster DNS config to add<br />this address as a stub nameserver for ts.net for cluster workloads to be<br />able to resolve MagicDNS names associated with egress or Ingress<br />proxies.<br />The IP address will change if you delete and recreate the DNSConfig. |  |  |
 
 
 #### NodePortConfig

k8s-operator/apis/v1alpha1/types_tsdnsconfig.go

@@ -82,6 +82,9 @@ type Nameserver struct {
 	// Nameserver image. Defaults to tailscale/k8s-nameserver:unstable.
 	// +optional
 	Image *NameserverImage `json:"image,omitempty"`
+	// Service configuration.
+	// +optional
+	Service *NameserverService `json:"service,omitempty"`
 }
 
 type NameserverImage struct {
@@ -93,6 +96,12 @@ type NameserverImage struct {
 	Tag string `json:"tag,omitempty"`
 }
 
+type NameserverService struct {
+	// ClusterIP sets the static IP of the service used by the nameserver.
+	// +optional
+	ClusterIP string `json:"clusterIP,omitempty"`
+}
+
 type DNSConfigStatus struct {
 	// +listType=map
 	// +listMapKey=type
@@ -105,7 +114,7 @@ type DNSConfigStatus struct {
 
 type NameserverStatus struct {
 	// IP is the ClusterIP of the Service fronting the deployed ts.net nameserver.
-	// Currently you must manually update your cluster DNS config to add
+	// Currently, you must manually update your cluster DNS config to add
 	// this address as a stub nameserver for ts.net for cluster workloads to be
 	// able to resolve MagicDNS names associated with egress or Ingress
 	// proxies.

k8s-operator/apis/v1alpha1/zz_generated.deepcopy.go

@@ -385,6 +385,11 @@ func (in *Nameserver) DeepCopyInto(out *Nameserver) {
 		*out = new(NameserverImage)
 		**out = **in
 	}
+	if in.Service != nil {
+		in, out := &in.Service, &out.Service
+		*out = new(NameserverService)
+		**out = **in
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new Nameserver.
@@ -412,6 +417,21 @@ func (in *NameserverImage) DeepCopy() *NameserverImage {
 	return out
 }
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *NameserverService) DeepCopyInto(out *NameserverService) {
+	*out = *in
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new NameserverService.
+func (in *NameserverService) DeepCopy() *NameserverService {
+	if in == nil {
+		return nil
+	}
+	out := new(NameserverService)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *NameserverStatus) DeepCopyInto(out *NameserverStatus) {
 	*out = *in