Add new resource for Kubernetes API proxy (#279)

This adds a new resource which deploys a Kubernetes API server proxy
that can be used to access the API server without tokens through
Netbird.

Part of #274 

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added ClusterProxy custom resource for cluster API proxying
capabilities

* **Documentation**
  * Added ClusterProxy API reference documentation with schema details

* **Examples**
* Added example ClusterProxy configuration and RBAC setup for cluster
proxy targets

<!-- review_stack_entry_start -->

[![Review Change
Stack](https://storage.googleapis.com/coderabbit_public_assets/review-stack-in-coderabbit-ui.svg)](https://app.coderabbit.ai/change-stack/netbirdio/kubernetes-operator/pull/279?utm_source=github_walkthrough&utm_medium=github&utm_campaign=change_stack)

<!-- review_stack_entry_end -->
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

pkg/applyconfigurations/api/v1alpha1/clusterproxy.go

@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Code generated by controller-gen. DO NOT EDIT.
+
+package v1alpha1
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	types "k8s.io/apimachinery/pkg/types"
+	v1 "k8s.io/client-go/applyconfigurations/meta/v1"
+)
+
+// ClusterProxyApplyConfiguration represents a declarative configuration of the ClusterProxy type for use
+// with apply.
+//
+// ClusterProxy is the Schema for the clusterproxies API
+type ClusterProxyApplyConfiguration struct {
+	v1.TypeMetaApplyConfiguration    `json:",inline"`
+	*v1.ObjectMetaApplyConfiguration `json:"metadata,omitempty"`
+	Spec                             *ClusterProxySpecApplyConfiguration   `json:"spec,omitempty"`
+	Status                           *ClusterProxyStatusApplyConfiguration `json:"status,omitempty"`
+}
+
+// ClusterProxy constructs a declarative configuration of the ClusterProxy type for use with
+// apply.
+func ClusterProxy(name, namespace string) *ClusterProxyApplyConfiguration {
+	b := &ClusterProxyApplyConfiguration{}
+	b.WithName(name)
+	b.WithNamespace(namespace)
+	b.WithKind("ClusterProxy")
+	b.WithAPIVersion("netbird.io/v1alpha1")
+	return b
+}
+
+func (b ClusterProxyApplyConfiguration) IsApplyConfiguration() {}
+
+// WithKind sets the Kind field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the Kind field is set to the value of the last call.
+func (b *ClusterProxyApplyConfiguration) WithKind(value string) *ClusterProxyApplyConfiguration {
+	b.TypeMetaApplyConfiguration.Kind = &value
+	return b
+}
+
+// WithAPIVersion sets the APIVersion field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the APIVersion field is set to the value of the last call.
+func (b *ClusterProxyApplyConfiguration) WithAPIVersion(value string) *ClusterProxyApplyConfiguration {
+	b.TypeMetaApplyConfiguration.APIVersion = &value
+	return b
+}
+
+// WithName sets the Name field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the Name field is set to the value of the last call.
+func (b *ClusterProxyApplyConfiguration) WithName(value string) *ClusterProxyApplyConfiguration {
+	b.ensureObjectMetaApplyConfigurationExists()
+	b.ObjectMetaApplyConfiguration.Name = &value
+	return b
+}
+
+// WithGenerateName sets the GenerateName field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the GenerateName field is set to the value of the last call.
+func (b *ClusterProxyApplyConfiguration) WithGenerateName(value string) *ClusterProxyApplyConfiguration {
+	b.ensureObjectMetaApplyConfigurationExists()
+	b.ObjectMetaApplyConfiguration.GenerateName = &value
+	return b
+}
+
+// WithNamespace sets the Namespace field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the Namespace field is set to the value of the last call.
+func (b *ClusterProxyApplyConfiguration) WithNamespace(value string) *ClusterProxyApplyConfiguration {
+	b.ensureObjectMetaApplyConfigurationExists()
+	b.ObjectMetaApplyConfiguration.Namespace = &value
+	return b
+}
+
+// WithUID sets the UID field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the UID field is set to the value of the last call.
+func (b *ClusterProxyApplyConfiguration) WithUID(value types.UID) *ClusterProxyApplyConfiguration {
+	b.ensureObjectMetaApplyConfigurationExists()
+	b.ObjectMetaApplyConfiguration.UID = &value
+	return b
+}
+
+// WithResourceVersion sets the ResourceVersion field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the ResourceVersion field is set to the value of the last call.
+func (b *ClusterProxyApplyConfiguration) WithResourceVersion(value string) *ClusterProxyApplyConfiguration {
+	b.ensureObjectMetaApplyConfigurationExists()
+	b.ObjectMetaApplyConfiguration.ResourceVersion = &value
+	return b
+}
+
+// WithGeneration sets the Generation field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the Generation field is set to the value of the last call.
+func (b *ClusterProxyApplyConfiguration) WithGeneration(value int64) *ClusterProxyApplyConfiguration {
+	b.ensureObjectMetaApplyConfigurationExists()
+	b.ObjectMetaApplyConfiguration.Generation = &value
+	return b
+}
+
+// WithCreationTimestamp sets the CreationTimestamp field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the CreationTimestamp field is set to the value of the last call.
+func (b *ClusterProxyApplyConfiguration) WithCreationTimestamp(value metav1.Time) *ClusterProxyApplyConfiguration {
+	b.ensureObjectMetaApplyConfigurationExists()
+	b.ObjectMetaApplyConfiguration.CreationTimestamp = &value
+	return b
+}
+
+// WithDeletionTimestamp sets the DeletionTimestamp field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the DeletionTimestamp field is set to the value of the last call.
+func (b *ClusterProxyApplyConfiguration) WithDeletionTimestamp(value metav1.Time) *ClusterProxyApplyConfiguration {
+	b.ensureObjectMetaApplyConfigurationExists()
+	b.ObjectMetaApplyConfiguration.DeletionTimestamp = &value
+	return b
+}
+
+// WithDeletionGracePeriodSeconds sets the DeletionGracePeriodSeconds field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the DeletionGracePeriodSeconds field is set to the value of the last call.
+func (b *ClusterProxyApplyConfiguration) WithDeletionGracePeriodSeconds(value int64) *ClusterProxyApplyConfiguration {
+	b.ensureObjectMetaApplyConfigurationExists()
+	b.ObjectMetaApplyConfiguration.DeletionGracePeriodSeconds = &value
+	return b
+}
+
+// WithLabels puts the entries into the Labels field in the declarative configuration
+// and returns the receiver, so that objects can be build by chaining "With" function invocations.
+// If called multiple times, the entries provided by each call will be put on the Labels field,
+// overwriting an existing map entries in Labels field with the same key.
+func (b *ClusterProxyApplyConfiguration) WithLabels(entries map[string]string) *ClusterProxyApplyConfiguration {
+	b.ensureObjectMetaApplyConfigurationExists()
+	if b.ObjectMetaApplyConfiguration.Labels == nil && len(entries) > 0 {
+		b.ObjectMetaApplyConfiguration.Labels = make(map[string]string, len(entries))
+	}
+	for k, v := range entries {
+		b.ObjectMetaApplyConfiguration.Labels[k] = v
+	}
+	return b
+}
+
+// WithAnnotations puts the entries into the Annotations field in the declarative configuration
+// and returns the receiver, so that objects can be build by chaining "With" function invocations.
+// If called multiple times, the entries provided by each call will be put on the Annotations field,
+// overwriting an existing map entries in Annotations field with the same key.
+func (b *ClusterProxyApplyConfiguration) WithAnnotations(entries map[string]string) *ClusterProxyApplyConfiguration {
+	b.ensureObjectMetaApplyConfigurationExists()
+	if b.ObjectMetaApplyConfiguration.Annotations == nil && len(entries) > 0 {
+		b.ObjectMetaApplyConfiguration.Annotations = make(map[string]string, len(entries))
+	}
+	for k, v := range entries {
+		b.ObjectMetaApplyConfiguration.Annotations[k] = v
+	}
+	return b
+}
+
+// WithOwnerReferences adds the given value to the OwnerReferences field in the declarative configuration
+// and returns the receiver, so that objects can be build by chaining "With" function invocations.
+// If called multiple times, values provided by each call will be appended to the OwnerReferences field.
+func (b *ClusterProxyApplyConfiguration) WithOwnerReferences(values ...*v1.OwnerReferenceApplyConfiguration) *ClusterProxyApplyConfiguration {
+	b.ensureObjectMetaApplyConfigurationExists()
+	for i := range values {
+		if values[i] == nil {
+			panic("nil value passed to WithOwnerReferences")
+		}
+		b.ObjectMetaApplyConfiguration.OwnerReferences = append(b.ObjectMetaApplyConfiguration.OwnerReferences, *values[i])
+	}
+	return b
+}
+
+// WithFinalizers adds the given value to the Finalizers field in the declarative configuration
+// and returns the receiver, so that objects can be build by chaining "With" function invocations.
+// If called multiple times, values provided by each call will be appended to the Finalizers field.
+func (b *ClusterProxyApplyConfiguration) WithFinalizers(values ...string) *ClusterProxyApplyConfiguration {
+	b.ensureObjectMetaApplyConfigurationExists()
+	for i := range values {
+		b.ObjectMetaApplyConfiguration.Finalizers = append(b.ObjectMetaApplyConfiguration.Finalizers, values[i])
+	}
+	return b
+}
+
+func (b *ClusterProxyApplyConfiguration) ensureObjectMetaApplyConfigurationExists() {
+	if b.ObjectMetaApplyConfiguration == nil {
+		b.ObjectMetaApplyConfiguration = &v1.ObjectMetaApplyConfiguration{}
+	}
+}
+
+// WithSpec sets the Spec field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the Spec field is set to the value of the last call.
+func (b *ClusterProxyApplyConfiguration) WithSpec(value *ClusterProxySpecApplyConfiguration) *ClusterProxyApplyConfiguration {
+	b.Spec = value
+	return b
+}
+
+// WithStatus sets the Status field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the Status field is set to the value of the last call.
+func (b *ClusterProxyApplyConfiguration) WithStatus(value *ClusterProxyStatusApplyConfiguration) *ClusterProxyApplyConfiguration {
+	b.Status = value
+	return b
+}
+
+// GetKind retrieves the value of the Kind field in the declarative configuration.
+func (b *ClusterProxyApplyConfiguration) GetKind() *string {
+	return b.TypeMetaApplyConfiguration.Kind
+}
+
+// GetAPIVersion retrieves the value of the APIVersion field in the declarative configuration.
+func (b *ClusterProxyApplyConfiguration) GetAPIVersion() *string {
+	return b.TypeMetaApplyConfiguration.APIVersion
+}
+
+// GetName retrieves the value of the Name field in the declarative configuration.
+func (b *ClusterProxyApplyConfiguration) GetName() *string {
+	b.ensureObjectMetaApplyConfigurationExists()
+	return b.ObjectMetaApplyConfiguration.Name
+}
+
+// GetNamespace retrieves the value of the Namespace field in the declarative configuration.
+func (b *ClusterProxyApplyConfiguration) GetNamespace() *string {
+	b.ensureObjectMetaApplyConfigurationExists()
+	return b.ObjectMetaApplyConfiguration.Namespace
+}

pkg/applyconfigurations/api/v1alpha1/clusterproxyspec.go

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Code generated by controller-gen. DO NOT EDIT.
+
+package v1alpha1
+
+// ClusterProxySpecApplyConfiguration represents a declarative configuration of the ClusterProxySpec type for use
+// with apply.
+//
+// ClusterProxySpec defines the desired state of ClusterProxy.
+type ClusterProxySpecApplyConfiguration struct {
+	// ClusterName is the name of the Kubernetes cluster.
+	ClusterName *string `json:"clusterName,omitempty"`
+	// APIServer is the URL of the Kubernetes API server to proxy requests to.
+	APIServer *string `json:"apiServer,omitempty"`
+	// ServiceAccountName is a reference to the service account used for impersonation.
+	ServiceAccountName *string `json:"serviceAccountName,omitempty"`
+}
+
+// ClusterProxySpecApplyConfiguration constructs a declarative configuration of the ClusterProxySpec type for use with
+// apply.
+func ClusterProxySpec() *ClusterProxySpecApplyConfiguration {
+	return &ClusterProxySpecApplyConfiguration{}
+}
+
+// WithClusterName sets the ClusterName field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the ClusterName field is set to the value of the last call.
+func (b *ClusterProxySpecApplyConfiguration) WithClusterName(value string) *ClusterProxySpecApplyConfiguration {
+	b.ClusterName = &value
+	return b
+}
+
+// WithAPIServer sets the APIServer field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the APIServer field is set to the value of the last call.
+func (b *ClusterProxySpecApplyConfiguration) WithAPIServer(value string) *ClusterProxySpecApplyConfiguration {
+	b.APIServer = &value
+	return b
+}
+
+// WithServiceAccountName sets the ServiceAccountName field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the ServiceAccountName field is set to the value of the last call.
+func (b *ClusterProxySpecApplyConfiguration) WithServiceAccountName(value string) *ClusterProxySpecApplyConfiguration {
+	b.ServiceAccountName = &value
+	return b
+}

pkg/applyconfigurations/api/v1alpha1/clusterproxystatus.go

@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Code generated by controller-gen. DO NOT EDIT.
+
+package v1alpha1
+
+import (
+	v1 "k8s.io/client-go/applyconfigurations/meta/v1"
+)
+
+// ClusterProxyStatusApplyConfiguration represents a declarative configuration of the ClusterProxyStatus type for use
+// with apply.
+//
+// ClusterProxyStatus defines the observed state of ClusterProxy.
+type ClusterProxyStatusApplyConfiguration struct {
+	// ObservedGeneration is the last reconciled generation.
+	ObservedGeneration *int64 `json:"observedGeneration,omitempty"`
+	// Conditions holds the conditions for the ClusterProxy.
+	Conditions []v1.ConditionApplyConfiguration `json:"conditions,omitempty"`
+}
+
+// ClusterProxyStatusApplyConfiguration constructs a declarative configuration of the ClusterProxyStatus type for use with
+// apply.
+func ClusterProxyStatus() *ClusterProxyStatusApplyConfiguration {
+	return &ClusterProxyStatusApplyConfiguration{}
+}
+
+// WithObservedGeneration sets the ObservedGeneration field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the ObservedGeneration field is set to the value of the last call.
+func (b *ClusterProxyStatusApplyConfiguration) WithObservedGeneration(value int64) *ClusterProxyStatusApplyConfiguration {
+	b.ObservedGeneration = &value
+	return b
+}
+
+// WithConditions adds the given value to the Conditions field in the declarative configuration
+// and returns the receiver, so that objects can be build by chaining "With" function invocations.
+// If called multiple times, values provided by each call will be appended to the Conditions field.
+func (b *ClusterProxyStatusApplyConfiguration) WithConditions(values ...*v1.ConditionApplyConfiguration) *ClusterProxyStatusApplyConfiguration {
+	for i := range values {
+		if values[i] == nil {
+			panic("nil value passed to WithConditions")
+		}
+		b.Conditions = append(b.Conditions, *values[i])
+	}
+	return b
+}