Merge pull request 'Add companion TSIG API and BindTSIGAPI CRD' (#8) from benvin/tsig-companion-api into main

Reviewed-on: #8

.woodpecker/build.yaml

@@ -8,3 +8,10 @@ steps:
       repo: git.unkin.net/unkin/bind-operator
       dockerfile: Dockerfile.operator
       dry_run: true
+
+  - name: docker-build-tsig-api
+    image: woodpeckerci/plugin-docker-buildx
+    settings:
+      repo: git.unkin.net/unkin/bind-tsig-api
+      dockerfile: Dockerfile.tsigapi
+      dry_run: true

.woodpecker/docker.yaml

@@ -15,3 +15,16 @@ steps:
       tags:
         - ${CI_COMMIT_TAG}
         - latest
+
+  - name: docker-tsig-api
+    image: woodpeckerci/plugin-docker-buildx
+    settings:
+      registry: git.unkin.net
+      repo: git.unkin.net/unkin/bind-tsig-api
+      dockerfile: Dockerfile.tsigapi
+      username: droneci
+      password:
+        from_secret: DRONECI_PASSWORD
+      tags:
+        - ${CI_COMMIT_TAG}
+        - latest

Dockerfile.tsigapi

@@ -0,0 +1,20 @@
+FROM golang:1.25-alpine AS builder
+
+RUN apk add --no-cache git
+
+WORKDIR /build
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+
+RUN CGO_ENABLED=0 go build -ldflags="-s -w" -o tsig-api ./cmd/tsigapi
+
+FROM gcr.io/distroless/static-debian12:nonroot
+
+COPY --from=builder /build/tsig-api /usr/local/bin/tsig-api
+
+EXPOSE 8443
+
+ENTRYPOINT ["tsig-api"]

api/v1alpha1/bindtsigapi_types.go

@@ -0,0 +1,104 @@
+package v1alpha1
+
+import (
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// BindTSIGAPISpec configures the companion TSIG API that the operator deploys.
+// The API exposes an HTTP contract (used by vault-plugin-secrets-bind-tsig) for
+// creating, rotating and deleting TSIG keys; it does so by managing BindTSIGKey
+// custom resources, which the operator then reconciles into key material.
+type BindTSIGAPISpec struct {
+	// Image is the companion API container image.
+	// +kubebuilder:default="git.unkin.net/unkin/bind-tsig-api:latest"
+	// +optional
+	Image string `json:"image,omitempty"`
+
+	// ImagePullPolicy for the API container.
+	// +optional
+	ImagePullPolicy corev1.PullPolicy `json:"imagePullPolicy,omitempty"`
+
+	// Replicas of the API. Defaults to 1.
+	// +kubebuilder:default=1
+	// +optional
+	Replicas int32 `json:"replicas,omitempty"`
+
+	// Port the API listens on. Defaults to 8443.
+	// +kubebuilder:default=8443
+	// +optional
+	Port int32 `json:"port,omitempty"`
+
+	// TargetNamespace is where the API creates BindTSIGKey resources. Defaults
+	// to the API's own namespace.
+	// +optional
+	TargetNamespace string `json:"targetNamespace,omitempty"`
+
+	// TokenSecretName holds the master access token clients present to the API.
+	// The operator generates a token if the Secret does not exist, so a
+	// VaultStaticSecret may pre-seed it instead. Defaults to "<name>-token".
+	// +optional
+	TokenSecretName string `json:"tokenSecretName,omitempty"`
+
+	// Env are extra environment variables rendered into the API ConfigMap.
+	// +optional
+	Env map[string]string `json:"env,omitempty"`
+
+	// Service controls how the API is exposed (defaults to ClusterIP).
+	// +optional
+	Service ClusterServiceSpec `json:"service,omitempty"`
+
+	// Resources for the API container.
+	// +optional
+	Resources corev1.ResourceRequirements `json:"resources,omitempty"`
+}
+
+// BindTSIGAPIStatus reports observed API state.
+type BindTSIGAPIStatus struct {
+	// +optional
+	Phase string `json:"phase,omitempty"`
+	// +optional
+	ReadyReplicas int32 `json:"readyReplicas,omitempty"`
+	// Endpoint is the in-cluster URL clients (Vault) use to reach the API.
+	// +optional
+	Endpoint string `json:"endpoint,omitempty"`
+	// TokenSecret is the Secret holding the master access token.
+	// +optional
+	TokenSecret string `json:"tokenSecret,omitempty"`
+	// +optional
+	ObservedGeneration int64 `json:"observedGeneration,omitempty"`
+	// +optional
+	// +listType=map
+	// +listMapKey=type
+	Conditions []metav1.Condition `json:"conditions,omitempty"`
+}
+
+// +kubebuilder:object:root=true
+// +kubebuilder:subresource:status
+// +kubebuilder:resource:shortName=btapi
+// +kubebuilder:printcolumn:name="Endpoint",type=string,JSONPath=`.status.endpoint`
+// +kubebuilder:printcolumn:name="Ready",type=integer,JSONPath=`.status.readyReplicas`
+// +kubebuilder:printcolumn:name="Phase",type=string,JSONPath=`.status.phase`
+
+// BindTSIGAPI deploys the companion TSIG API. Creating one makes the operator
+// reconcile a Deployment, Service, ConfigMap, token Secret and RBAC for it.
+type BindTSIGAPI struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	Spec   BindTSIGAPISpec   `json:"spec,omitempty"`
+	Status BindTSIGAPIStatus `json:"status,omitempty"`
+}
+
+// +kubebuilder:object:root=true
+
+// BindTSIGAPIList contains a list of BindTSIGAPI.
+type BindTSIGAPIList struct {
+	metav1.TypeMeta `json:",inline"`
+	metav1.ListMeta `json:"metadata,omitempty"`
+	Items           []BindTSIGAPI `json:"items"`
+}
+
+func init() {
+	SchemeBuilder.Register(&BindTSIGAPI{}, &BindTSIGAPIList{})
+}

api/v1alpha1/zz_generated.deepcopy.go

@@ -581,6 +581,111 @@ func (in *BindPolicyStatus) DeepCopy() *BindPolicyStatus {
 	return out
 }
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *BindTSIGAPI) DeepCopyInto(out *BindTSIGAPI) {
+	*out = *in
+	out.TypeMeta = in.TypeMeta
+	in.ObjectMeta.DeepCopyInto(&out.ObjectMeta)
+	in.Spec.DeepCopyInto(&out.Spec)
+	in.Status.DeepCopyInto(&out.Status)
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new BindTSIGAPI.
+func (in *BindTSIGAPI) DeepCopy() *BindTSIGAPI {
+	if in == nil {
+		return nil
+	}
+	out := new(BindTSIGAPI)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
+func (in *BindTSIGAPI) DeepCopyObject() runtime.Object {
+	if c := in.DeepCopy(); c != nil {
+		return c
+	}
+	return nil
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *BindTSIGAPIList) DeepCopyInto(out *BindTSIGAPIList) {
+	*out = *in
+	out.TypeMeta = in.TypeMeta
+	in.ListMeta.DeepCopyInto(&out.ListMeta)
+	if in.Items != nil {
+		in, out := &in.Items, &out.Items
+		*out = make([]BindTSIGAPI, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new BindTSIGAPIList.
+func (in *BindTSIGAPIList) DeepCopy() *BindTSIGAPIList {
+	if in == nil {
+		return nil
+	}
+	out := new(BindTSIGAPIList)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
+func (in *BindTSIGAPIList) DeepCopyObject() runtime.Object {
+	if c := in.DeepCopy(); c != nil {
+		return c
+	}
+	return nil
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *BindTSIGAPISpec) DeepCopyInto(out *BindTSIGAPISpec) {
+	*out = *in
+	if in.Env != nil {
+		in, out := &in.Env, &out.Env
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
+	in.Service.DeepCopyInto(&out.Service)
+	in.Resources.DeepCopyInto(&out.Resources)
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new BindTSIGAPISpec.
+func (in *BindTSIGAPISpec) DeepCopy() *BindTSIGAPISpec {
+	if in == nil {
+		return nil
+	}
+	out := new(BindTSIGAPISpec)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *BindTSIGAPIStatus) DeepCopyInto(out *BindTSIGAPIStatus) {
+	*out = *in
+	if in.Conditions != nil {
+		in, out := &in.Conditions, &out.Conditions
+		*out = make([]v1.Condition, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new BindTSIGAPIStatus.
+func (in *BindTSIGAPIStatus) DeepCopy() *BindTSIGAPIStatus {
+	if in == nil {
+		return nil
+	}
+	out := new(BindTSIGAPIStatus)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *BindTSIGKey) DeepCopyInto(out *BindTSIGKey) {
 	*out = *in

cmd/tsigapi/main.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"net/http"
+	"os"
+	"time"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/log/zap"
+
+	bindv1alpha1 "git.unkin.net/unkin/bind-operator/api/v1alpha1"
+	"git.unkin.net/unkin/bind-operator/internal/tsigapi"
+)
+
+var scheme = runtime.NewScheme()
+
+func init() {
+	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
+	utilruntime.Must(bindv1alpha1.AddToScheme(scheme))
+}
+
+func main() {
+	ctrl.SetLogger(zap.New(zap.UseDevMode(false)))
+	logger := ctrl.Log.WithName("tsig-api")
+
+	addr := envOr("LISTEN_ADDR", ":8443")
+	namespace := envOr("TARGET_NAMESPACE", currentNamespace())
+	token := os.Getenv("API_TOKEN")
+
+	c, err := client.New(ctrl.GetConfigOrDie(), client.Options{Scheme: scheme})
+	if err != nil {
+		logger.Error(err, "unable to build kubernetes client")
+		os.Exit(1)
+	}
+
+	srv := &tsigapi.Server{
+		Client:      c,
+		Namespace:   namespace,
+		Token:       token,
+		Log:         logger,
+		WaitTimeout: 15 * time.Second,
+	}
+
+	httpSrv := &http.Server{
+		Addr:              addr,
+		Handler:           srv.Handler(),
+		ReadHeaderTimeout: 10 * time.Second,
+	}
+	logger.Info("starting tsig api", "addr", addr, "namespace", namespace)
+	if err := httpSrv.ListenAndServe(); err != nil {
+		logger.Error(err, "tsig api exited")
+		os.Exit(1)
+	}
+}
+
+func envOr(key, fallback string) string {
+	if v := os.Getenv(key); v != "" {
+		return v
+	}
+	return fallback
+}
+
+func currentNamespace() string {
+	if b, err := os.ReadFile("/var/run/secrets/kubernetes.io/serviceaccount/namespace"); err == nil {
+		return string(b)
+	}
+	return "bind-system"
+}

config/crd/bases/bind.unkin.net_bindtsigapis.yaml

@@ -0,0 +1,267 @@
+---
+apiVersion: apiextensions.k8s.io/v1
+kind: CustomResourceDefinition
+metadata:
+  annotations:
+    controller-gen.kubebuilder.io/version: v0.17.3
+  name: bindtsigapis.bind.unkin.net
+spec:
+  group: bind.unkin.net
+  names:
+    kind: BindTSIGAPI
+    listKind: BindTSIGAPIList
+    plural: bindtsigapis
+    shortNames:
+    - btapi
+    singular: bindtsigapi
+  scope: Namespaced
+  versions:
+  - additionalPrinterColumns:
+    - jsonPath: .status.endpoint
+      name: Endpoint
+      type: string
+    - jsonPath: .status.readyReplicas
+      name: Ready
+      type: integer
+    - jsonPath: .status.phase
+      name: Phase
+      type: string
+    name: v1alpha1
+    schema:
+      openAPIV3Schema:
+        description: |-
+          BindTSIGAPI deploys the companion TSIG API. Creating one makes the operator
+          reconcile a Deployment, Service, ConfigMap, token Secret and RBAC for it.
+        properties:
+          apiVersion:
+            description: |-
+              APIVersion defines the versioned schema of this representation of an object.
+              Servers should convert recognized schemas to the latest internal value, and
+              may reject unrecognized values.
+              More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources
+            type: string
+          kind:
+            description: |-
+              Kind is a string value representing the REST resource this object represents.
+              Servers may infer this from the endpoint the client submits requests to.
+              Cannot be updated.
+              In CamelCase.
+              More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds
+            type: string
+          metadata:
+            type: object
+          spec:
+            description: |-
+              BindTSIGAPISpec configures the companion TSIG API that the operator deploys.
+              The API exposes an HTTP contract (used by vault-plugin-secrets-bind-tsig) for
+              creating, rotating and deleting TSIG keys; it does so by managing BindTSIGKey
+              custom resources, which the operator then reconciles into key material.
+            properties:
+              env:
+                additionalProperties:
+                  type: string
+                description: Env are extra environment variables rendered into the
+                  API ConfigMap.
+                type: object
+              image:
+                default: git.unkin.net/unkin/bind-tsig-api:latest
+                description: Image is the companion API container image.
+                type: string
+              imagePullPolicy:
+                description: ImagePullPolicy for the API container.
+                type: string
+              port:
+                default: 8443
+                description: Port the API listens on. Defaults to 8443.
+                format: int32
+                type: integer
+              replicas:
+                default: 1
+                description: Replicas of the API. Defaults to 1.
+                format: int32
+                type: integer
+              resources:
+                description: Resources for the API container.
+                properties:
+                  claims:
+                    description: |-
+                      Claims lists the names of resources, defined in spec.resourceClaims,
+                      that are used by this container.
+
+                      This field depends on the
+                      DynamicResourceAllocation feature gate.
+
+                      This field is immutable. It can only be set for containers.
+                    items:
+                      description: ResourceClaim references one entry in PodSpec.ResourceClaims.
+                      properties:
+                        name:
+                          description: |-
+                            Name must match the name of one entry in pod.spec.resourceClaims of
+                            the Pod where this field is used. It makes that resource available
+                            inside a container.
+                          type: string
+                        request:
+                          description: |-
+                            Request is the name chosen for a request in the referenced claim.
+                            If empty, everything from the claim is made available, otherwise
+                            only the result of this request.
+                          type: string
+                      required:
+                      - name
+                      type: object
+                    type: array
+                    x-kubernetes-list-map-keys:
+                    - name
+                    x-kubernetes-list-type: map
+                  limits:
+                    additionalProperties:
+                      anyOf:
+                      - type: integer
+                      - type: string
+                      pattern: ^(\+|-)?(([0-9]+(\.[0-9]*)?)|(\.[0-9]+))(([KMGTPE]i)|[numkMGTPE]|([eE](\+|-)?(([0-9]+(\.[0-9]*)?)|(\.[0-9]+))))?$
+                      x-kubernetes-int-or-string: true
+                    description: |-
+                      Limits describes the maximum amount of compute resources allowed.
+                      More info: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
+                    type: object
+                  requests:
+                    additionalProperties:
+                      anyOf:
+                      - type: integer
+                      - type: string
+                      pattern: ^(\+|-)?(([0-9]+(\.[0-9]*)?)|(\.[0-9]+))(([KMGTPE]i)|[numkMGTPE]|([eE](\+|-)?(([0-9]+(\.[0-9]*)?)|(\.[0-9]+))))?$
+                      x-kubernetes-int-or-string: true
+                    description: |-
+                      Requests describes the minimum amount of compute resources required.
+                      If Requests is omitted for a container, it defaults to Limits if that is explicitly specified,
+                      otherwise to an implementation-defined value. Requests cannot exceed Limits.
+                      More info: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
+                    type: object
+                type: object
+              service:
+                description: Service controls how the API is exposed (defaults to
+                  ClusterIP).
+                properties:
+                  annotations:
+                    additionalProperties:
+                      type: string
+                    description: Annotations added to the client-facing Service (e.g.
+                      PureLB/MetalLB hints).
+                    type: object
+                  externalTrafficPolicy:
+                    description: |-
+                      ExternalTrafficPolicy for a LoadBalancer/NodePort Service. Local preserves
+                      client source IPs (required for source-IP ACLs on the DNS servers) but
+                      only routes to nodes running a pod. Defaults to Cluster.
+                    enum:
+                    - Cluster
+                    - Local
+                    type: string
+                  loadBalancerIP:
+                    description: LoadBalancerIP requests a specific address when Type
+                      is LoadBalancer.
+                    type: string
+                  type:
+                    description: Type of the client-facing Service. Defaults to ClusterIP.
+                    enum:
+                    - ClusterIP
+                    - LoadBalancer
+                    - NodePort
+                    type: string
+                type: object
+              targetNamespace:
+                description: |-
+                  TargetNamespace is where the API creates BindTSIGKey resources. Defaults
+                  to the API's own namespace.
+                type: string
+              tokenSecretName:
+                description: |-
+                  TokenSecretName holds the master access token clients present to the API.
+                  The operator generates a token if the Secret does not exist, so a
+                  VaultStaticSecret may pre-seed it instead. Defaults to "<name>-token".
+                type: string
+            type: object
+          status:
+            description: BindTSIGAPIStatus reports observed API state.
+            properties:
+              conditions:
+                items:
+                  description: Condition contains details for one aspect of the current
+                    state of this API Resource.
+                  properties:
+                    lastTransitionTime:
+                      description: |-
+                        lastTransitionTime is the last time the condition transitioned from one status to another.
+                        This should be when the underlying condition changed.  If that is not known, then using the time when the API field changed is acceptable.
+                      format: date-time
+                      type: string
+                    message:
+                      description: |-
+                        message is a human readable message indicating details about the transition.
+                        This may be an empty string.
+                      maxLength: 32768
+                      type: string
+                    observedGeneration:
+                      description: |-
+                        observedGeneration represents the .metadata.generation that the condition was set based upon.
+                        For instance, if .metadata.generation is currently 12, but the .status.conditions[x].observedGeneration is 9, the condition is out of date
+                        with respect to the current state of the instance.
+                      format: int64
+                      minimum: 0
+                      type: integer
+                    reason:
+                      description: |-
+                        reason contains a programmatic identifier indicating the reason for the condition's last transition.
+                        Producers of specific condition types may define expected values and meanings for this field,
+                        and whether the values are considered a guaranteed API.
+                        The value should be a CamelCase string.
+                        This field may not be empty.
+                      maxLength: 1024
+                      minLength: 1
+                      pattern: ^[A-Za-z]([A-Za-z0-9_,:]*[A-Za-z0-9_])?$
+                      type: string
+                    status:
+                      description: status of the condition, one of True, False, Unknown.
+                      enum:
+                      - "True"
+                      - "False"
+                      - Unknown
+                      type: string
+                    type:
+                      description: type of condition in CamelCase or in foo.example.com/CamelCase.
+                      maxLength: 316
+                      pattern: ^([a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*/)?(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])$
+                      type: string
+                  required:
+                  - lastTransitionTime
+                  - message
+                  - reason
+                  - status
+                  - type
+                  type: object
+                type: array
+                x-kubernetes-list-map-keys:
+                - type
+                x-kubernetes-list-type: map
+              endpoint:
+                description: Endpoint is the in-cluster URL clients (Vault) use to
+                  reach the API.
+                type: string
+              observedGeneration:
+                format: int64
+                type: integer
+              phase:
+                type: string
+              readyReplicas:
+                format: int32
+                type: integer
+              tokenSecret:
+                description: TokenSecret is the Secret holding the master access token.
+                type: string
+            type: object
+        type: object
+    served: true
+    storage: true
+    subresources:
+      status: {}

config/crd/install.yaml

@@ -2023,6 +2023,273 @@ spec:
 ---
 apiVersion: apiextensions.k8s.io/v1
 kind: CustomResourceDefinition
+metadata:
+  annotations:
+    controller-gen.kubebuilder.io/version: v0.17.3
+  name: bindtsigapis.bind.unkin.net
+spec:
+  group: bind.unkin.net
+  names:
+    kind: BindTSIGAPI
+    listKind: BindTSIGAPIList
+    plural: bindtsigapis
+    shortNames:
+    - btapi
+    singular: bindtsigapi
+  scope: Namespaced
+  versions:
+  - additionalPrinterColumns:
+    - jsonPath: .status.endpoint
+      name: Endpoint
+      type: string
+    - jsonPath: .status.readyReplicas
+      name: Ready
+      type: integer
+    - jsonPath: .status.phase
+      name: Phase
+      type: string
+    name: v1alpha1
+    schema:
+      openAPIV3Schema:
+        description: |-
+          BindTSIGAPI deploys the companion TSIG API. Creating one makes the operator
+          reconcile a Deployment, Service, ConfigMap, token Secret and RBAC for it.
+        properties:
+          apiVersion:
+            description: |-
+              APIVersion defines the versioned schema of this representation of an object.
+              Servers should convert recognized schemas to the latest internal value, and
+              may reject unrecognized values.
+              More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources
+            type: string
+          kind:
+            description: |-
+              Kind is a string value representing the REST resource this object represents.
+              Servers may infer this from the endpoint the client submits requests to.
+              Cannot be updated.
+              In CamelCase.
+              More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds
+            type: string
+          metadata:
+            type: object
+          spec:
+            description: |-
+              BindTSIGAPISpec configures the companion TSIG API that the operator deploys.
+              The API exposes an HTTP contract (used by vault-plugin-secrets-bind-tsig) for
+              creating, rotating and deleting TSIG keys; it does so by managing BindTSIGKey
+              custom resources, which the operator then reconciles into key material.
+            properties:
+              env:
+                additionalProperties:
+                  type: string
+                description: Env are extra environment variables rendered into the
+                  API ConfigMap.
+                type: object
+              image:
+                default: git.unkin.net/unkin/bind-tsig-api:latest
+                description: Image is the companion API container image.
+                type: string
+              imagePullPolicy:
+                description: ImagePullPolicy for the API container.
+                type: string
+              port:
+                default: 8443
+                description: Port the API listens on. Defaults to 8443.
+                format: int32
+                type: integer
+              replicas:
+                default: 1
+                description: Replicas of the API. Defaults to 1.
+                format: int32
+                type: integer
+              resources:
+                description: Resources for the API container.
+                properties:
+                  claims:
+                    description: |-
+                      Claims lists the names of resources, defined in spec.resourceClaims,
+                      that are used by this container.
+
+                      This field depends on the
+                      DynamicResourceAllocation feature gate.
+
+                      This field is immutable. It can only be set for containers.
+                    items:
+                      description: ResourceClaim references one entry in PodSpec.ResourceClaims.
+                      properties:
+                        name:
+                          description: |-
+                            Name must match the name of one entry in pod.spec.resourceClaims of
+                            the Pod where this field is used. It makes that resource available
+                            inside a container.
+                          type: string
+                        request:
+                          description: |-
+                            Request is the name chosen for a request in the referenced claim.
+                            If empty, everything from the claim is made available, otherwise
+                            only the result of this request.
+                          type: string
+                      required:
+                      - name
+                      type: object
+                    type: array
+                    x-kubernetes-list-map-keys:
+                    - name
+                    x-kubernetes-list-type: map
+                  limits:
+                    additionalProperties:
+                      anyOf:
+                      - type: integer
+                      - type: string
+                      pattern: ^(\+|-)?(([0-9]+(\.[0-9]*)?)|(\.[0-9]+))(([KMGTPE]i)|[numkMGTPE]|([eE](\+|-)?(([0-9]+(\.[0-9]*)?)|(\.[0-9]+))))?$
+                      x-kubernetes-int-or-string: true
+                    description: |-
+                      Limits describes the maximum amount of compute resources allowed.
+                      More info: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
+                    type: object
+                  requests:
+                    additionalProperties:
+                      anyOf:
+                      - type: integer
+                      - type: string
+                      pattern: ^(\+|-)?(([0-9]+(\.[0-9]*)?)|(\.[0-9]+))(([KMGTPE]i)|[numkMGTPE]|([eE](\+|-)?(([0-9]+(\.[0-9]*)?)|(\.[0-9]+))))?$
+                      x-kubernetes-int-or-string: true
+                    description: |-
+                      Requests describes the minimum amount of compute resources required.
+                      If Requests is omitted for a container, it defaults to Limits if that is explicitly specified,
+                      otherwise to an implementation-defined value. Requests cannot exceed Limits.
+                      More info: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
+                    type: object
+                type: object
+              service:
+                description: Service controls how the API is exposed (defaults to
+                  ClusterIP).
+                properties:
+                  annotations:
+                    additionalProperties:
+                      type: string
+                    description: Annotations added to the client-facing Service (e.g.
+                      PureLB/MetalLB hints).
+                    type: object
+                  externalTrafficPolicy:
+                    description: |-
+                      ExternalTrafficPolicy for a LoadBalancer/NodePort Service. Local preserves
+                      client source IPs (required for source-IP ACLs on the DNS servers) but
+                      only routes to nodes running a pod. Defaults to Cluster.
+                    enum:
+                    - Cluster
+                    - Local
+                    type: string
+                  loadBalancerIP:
+                    description: LoadBalancerIP requests a specific address when Type
+                      is LoadBalancer.
+                    type: string
+                  type:
+                    description: Type of the client-facing Service. Defaults to ClusterIP.
+                    enum:
+                    - ClusterIP
+                    - LoadBalancer
+                    - NodePort
+                    type: string
+                type: object
+              targetNamespace:
+                description: |-
+                  TargetNamespace is where the API creates BindTSIGKey resources. Defaults
+                  to the API's own namespace.
+                type: string
+              tokenSecretName:
+                description: |-
+                  TokenSecretName holds the master access token clients present to the API.
+                  The operator generates a token if the Secret does not exist, so a
+                  VaultStaticSecret may pre-seed it instead. Defaults to "<name>-token".
+                type: string
+            type: object
+          status:
+            description: BindTSIGAPIStatus reports observed API state.
+            properties:
+              conditions:
+                items:
+                  description: Condition contains details for one aspect of the current
+                    state of this API Resource.
+                  properties:
+                    lastTransitionTime:
+                      description: |-
+                        lastTransitionTime is the last time the condition transitioned from one status to another.
+                        This should be when the underlying condition changed.  If that is not known, then using the time when the API field changed is acceptable.
+                      format: date-time
+                      type: string
+                    message:
+                      description: |-
+                        message is a human readable message indicating details about the transition.
+                        This may be an empty string.
+                      maxLength: 32768
+                      type: string
+                    observedGeneration:
+                      description: |-
+                        observedGeneration represents the .metadata.generation that the condition was set based upon.
+                        For instance, if .metadata.generation is currently 12, but the .status.conditions[x].observedGeneration is 9, the condition is out of date
+                        with respect to the current state of the instance.
+                      format: int64
+                      minimum: 0
+                      type: integer
+                    reason:
+                      description: |-
+                        reason contains a programmatic identifier indicating the reason for the condition's last transition.
+                        Producers of specific condition types may define expected values and meanings for this field,
+                        and whether the values are considered a guaranteed API.
+                        The value should be a CamelCase string.
+                        This field may not be empty.
+                      maxLength: 1024
+                      minLength: 1
+                      pattern: ^[A-Za-z]([A-Za-z0-9_,:]*[A-Za-z0-9_])?$
+                      type: string
+                    status:
+                      description: status of the condition, one of True, False, Unknown.
+                      enum:
+                      - "True"
+                      - "False"
+                      - Unknown
+                      type: string
+                    type:
+                      description: type of condition in CamelCase or in foo.example.com/CamelCase.
+                      maxLength: 316
+                      pattern: ^([a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*/)?(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])$
+                      type: string
+                  required:
+                  - lastTransitionTime
+                  - message
+                  - reason
+                  - status
+                  - type
+                  type: object
+                type: array
+                x-kubernetes-list-map-keys:
+                - type
+                x-kubernetes-list-type: map
+              endpoint:
+                description: Endpoint is the in-cluster URL clients (Vault) use to
+                  reach the API.
+                type: string
+              observedGeneration:
+                format: int64
+                type: integer
+              phase:
+                type: string
+              readyReplicas:
+                format: int32
+                type: integer
+              tokenSecret:
+                description: TokenSecret is the Secret holding the master access token.
+                type: string
+            type: object
+        type: object
+    served: true
+    storage: true
+    subresources:
+      status: {}
+---
+apiVersion: apiextensions.k8s.io/v1
+kind: CustomResourceDefinition
 metadata:
   annotations:
     controller-gen.kubebuilder.io/version: v0.17.3

config/rbac/role.yaml

@@ -9,6 +9,7 @@ rules:
   resources:
   - configmaps
   - secrets
+  - serviceaccounts
   - services
   verbs:
   - create
@@ -36,6 +37,7 @@ rules:
 - apiGroups:
   - apps
   resources:
+  - deployments
   - statefulsets
   verbs:
   - create
@@ -53,6 +55,7 @@ rules:
   - bindclusters
   - binddnssecpolicies
   - bindpolicies
+  - bindtsigapis
   - bindtsigkeys
   - bindviews
   - bindzones
@@ -73,6 +76,7 @@ rules:
   - bindclusters/status
   - binddnssecpolicies/status
   - bindpolicies/status
+  - bindtsigapis/status
   - bindtsigkeys/status
   - bindviews/status
   - bindzones/status
@@ -81,3 +85,16 @@ rules:
   - get
   - patch
   - update
+- apiGroups:
+  - rbac.authorization.k8s.io
+  resources:
+  - rolebindings
+  - roles
+  verbs:
+  - create
+  - delete
+  - get
+  - list
+  - patch
+  - update
+  - watch

internal/controller/bindtsigapi_controller.go

@@ -0,0 +1,274 @@
+package controller
+
+import (
+	"context"
+	"fmt"
+
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	rbacv1 "k8s.io/api/rbac/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/types"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/log"
+
+	bindv1alpha1 "git.unkin.net/unkin/bind-operator/api/v1alpha1"
+	"git.unkin.net/unkin/bind-operator/internal/bind"
+)
+
+// BindTSIGAPIReconciler deploys the companion TSIG API (Deployment, Service,
+// ConfigMap, token Secret and RBAC) when a BindTSIGAPI resource exists.
+type BindTSIGAPIReconciler struct {
+	client.Client
+	Scheme *runtime.Scheme
+}
+
+// +kubebuilder:rbac:groups=bind.unkin.net,resources=bindtsigapis,verbs=get;list;watch;create;update;patch;delete
+// +kubebuilder:rbac:groups=bind.unkin.net,resources=bindtsigapis/status,verbs=get;update;patch
+// +kubebuilder:rbac:groups=apps,resources=deployments,verbs=get;list;watch;create;update;patch;delete
+// +kubebuilder:rbac:groups="",resources=serviceaccounts,verbs=get;list;watch;create;update;patch;delete
+// +kubebuilder:rbac:groups=rbac.authorization.k8s.io,resources=roles;rolebindings,verbs=get;list;watch;create;update;patch;delete
+
+func (r *BindTSIGAPIReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
+	logger := log.FromContext(ctx)
+
+	var api bindv1alpha1.BindTSIGAPI
+	if err := r.Get(ctx, req.NamespacedName, &api); err != nil {
+		return ctrl.Result{}, client.IgnoreNotFound(err)
+	}
+
+	tokenSecret := api.Spec.TokenSecretName
+	if tokenSecret == "" {
+		tokenSecret = api.Name + "-token"
+	}
+	targetNS := api.Spec.TargetNamespace
+	if targetNS == "" {
+		targetNS = api.Namespace
+	}
+
+	for _, step := range []func(context.Context, *bindv1alpha1.BindTSIGAPI, string, string) error{
+		r.reconcileServiceAccount,
+		r.reconcileRBAC,
+		r.reconcileTokenSecret,
+		r.reconcileConfigMap,
+		r.reconcileDeployment,
+		r.reconcileService,
+	} {
+		if err := step(ctx, &api, tokenSecret, targetNS); err != nil {
+			return ctrl.Result{}, err
+		}
+	}
+
+	// Status from the Deployment.
+	var dep appsv1.Deployment
+	_ = r.Get(ctx, types.NamespacedName{Namespace: api.Namespace, Name: api.Name}, &dep)
+	port := api.Spec.Port
+	if port == 0 {
+		port = 8443
+	}
+	api.Status.ReadyReplicas = dep.Status.ReadyReplicas
+	api.Status.Endpoint = fmt.Sprintf("http://%s.%s.svc:%d", api.Name, api.Namespace, port)
+	api.Status.TokenSecret = tokenSecret
+	api.Status.ObservedGeneration = api.Generation
+	ready := dep.Status.ReadyReplicas > 0
+	if ready {
+		api.Status.Phase = "Ready"
+	} else {
+		api.Status.Phase = "Progressing"
+	}
+	setReady(&api.Status.Conditions, api.Generation, ready, "Reconciled", fmt.Sprintf("%d ready", dep.Status.ReadyReplicas))
+	if err := r.Status().Update(ctx, &api); err != nil {
+		return ctrl.Result{}, err
+	}
+	if !ready {
+		return ctrl.Result{RequeueAfter: requeueShort}, nil
+	}
+	logger.V(1).Info("tsig api reconciled", "api", api.Name)
+	return ctrl.Result{}, nil
+}
+
+func tsigAPILabels(name string) map[string]string {
+	return map[string]string{
+		managedByLabel:                managedByValue,
+		"app.kubernetes.io/name":      "bind-tsig-api",
+		"app.kubernetes.io/instance":  name,
+		"app.kubernetes.io/component": "tsig-api",
+	}
+}
+
+func (r *BindTSIGAPIReconciler) reconcileServiceAccount(ctx context.Context, api *bindv1alpha1.BindTSIGAPI, _, _ string) error {
+	sa := &corev1.ServiceAccount{ObjectMeta: metav1.ObjectMeta{Name: api.Name, Namespace: api.Namespace, Labels: tsigAPILabels(api.Name)}}
+	return r.apply(ctx, api, sa, func() {})
+}
+
+func (r *BindTSIGAPIReconciler) reconcileRBAC(ctx context.Context, api *bindv1alpha1.BindTSIGAPI, _, targetNS string) error {
+	role := &rbacv1.Role{ObjectMeta: metav1.ObjectMeta{Name: api.Name, Namespace: targetNS, Labels: tsigAPILabels(api.Name)}}
+	if err := r.applyIn(ctx, api, role, targetNS, func() {
+		role.Rules = []rbacv1.PolicyRule{
+			{APIGroups: []string{"bind.unkin.net"}, Resources: []string{"bindtsigkeys"}, Verbs: []string{"get", "list", "watch", "create", "update", "patch", "delete"}},
+			{APIGroups: []string{"bind.unkin.net"}, Resources: []string{"bindtsigkeys/status"}, Verbs: []string{"get"}},
+			{APIGroups: []string{""}, Resources: []string{"secrets"}, Verbs: []string{"get", "list", "watch", "delete"}},
+		}
+	}); err != nil {
+		return err
+	}
+	rb := &rbacv1.RoleBinding{ObjectMeta: metav1.ObjectMeta{Name: api.Name, Namespace: targetNS, Labels: tsigAPILabels(api.Name)}}
+	return r.applyIn(ctx, api, rb, targetNS, func() {
+		rb.RoleRef = rbacv1.RoleRef{APIGroup: "rbac.authorization.k8s.io", Kind: "Role", Name: api.Name}
+		rb.Subjects = []rbacv1.Subject{{Kind: "ServiceAccount", Name: api.Name, Namespace: api.Namespace}}
+	})
+}
+
+// reconcileTokenSecret creates the master-access-token Secret only when it does
+// not already exist, so a VaultStaticSecret may pre-seed it. Not owned by the
+// BindTSIGAPI, so it survives and stays overwritable.
+func (r *BindTSIGAPIReconciler) reconcileTokenSecret(ctx context.Context, api *bindv1alpha1.BindTSIGAPI, tokenSecret, _ string) error {
+	var existing corev1.Secret
+	err := r.Get(ctx, types.NamespacedName{Namespace: api.Namespace, Name: tokenSecret}, &existing)
+	if err == nil {
+		return nil
+	}
+	if !apierrors.IsNotFound(err) {
+		return err
+	}
+	token, genErr := bind.GenerateSecret(32)
+	if genErr != nil {
+		return genErr
+	}
+	s := &corev1.Secret{
+		ObjectMeta: metav1.ObjectMeta{Name: tokenSecret, Namespace: api.Namespace, Labels: tsigAPILabels(api.Name)},
+		Data:       map[string][]byte{"token": []byte(token)},
+	}
+	return r.Create(ctx, s)
+}
+
+func (r *BindTSIGAPIReconciler) reconcileConfigMap(ctx context.Context, api *bindv1alpha1.BindTSIGAPI, _, targetNS string) error {
+	cm := &corev1.ConfigMap{ObjectMeta: metav1.ObjectMeta{Name: api.Name + "-config", Namespace: api.Namespace, Labels: tsigAPILabels(api.Name)}}
+	return r.apply(ctx, api, cm, func() {
+		port := api.Spec.Port
+		if port == 0 {
+			port = 8443
+		}
+		data := map[string]string{
+			"LISTEN_ADDR":      fmt.Sprintf(":%d", port),
+			"TARGET_NAMESPACE": targetNS,
+		}
+		for k, v := range api.Spec.Env {
+			data[k] = v
+		}
+		cm.Data = data
+	})
+}
+
+func (r *BindTSIGAPIReconciler) reconcileDeployment(ctx context.Context, api *bindv1alpha1.BindTSIGAPI, tokenSecret, _ string) error {
+	dep := &appsv1.Deployment{ObjectMeta: metav1.ObjectMeta{Name: api.Name, Namespace: api.Namespace, Labels: tsigAPILabels(api.Name)}}
+	return r.apply(ctx, api, dep, func() {
+		replicas := api.Spec.Replicas
+		if replicas == 0 {
+			replicas = 1
+		}
+		image := api.Spec.Image
+		if image == "" {
+			image = "git.unkin.net/unkin/bind-tsig-api:latest"
+		}
+		port := api.Spec.Port
+		if port == 0 {
+			port = 8443
+		}
+		labels := tsigAPILabels(api.Name)
+		dep.Spec = appsv1.DeploymentSpec{
+			Replicas: &replicas,
+			Selector: &metav1.LabelSelector{MatchLabels: map[string]string{"app.kubernetes.io/instance": api.Name}},
+			Template: corev1.PodTemplateSpec{
+				ObjectMeta: metav1.ObjectMeta{Labels: labels},
+				Spec: corev1.PodSpec{
+					ServiceAccountName: api.Name,
+					SecurityContext:    &corev1.PodSecurityContext{RunAsNonRoot: ptr(true)},
+					Containers: []corev1.Container{{
+						Name:            "tsig-api",
+						Image:           image,
+						ImagePullPolicy: api.Spec.ImagePullPolicy,
+						Command:         []string{"tsig-api"},
+						Ports:           []corev1.ContainerPort{{Name: "https", ContainerPort: port}},
+						EnvFrom:         []corev1.EnvFromSource{{ConfigMapRef: &corev1.ConfigMapEnvSource{LocalObjectReference: corev1.LocalObjectReference{Name: api.Name + "-config"}}}},
+						Env: []corev1.EnvVar{{
+							Name:      "API_TOKEN",
+							ValueFrom: &corev1.EnvVarSource{SecretKeyRef: &corev1.SecretKeySelector{LocalObjectReference: corev1.LocalObjectReference{Name: tokenSecret}, Key: "token"}},
+						}},
+						Resources: api.Spec.Resources,
+						ReadinessProbe: &corev1.Probe{
+							ProbeHandler:        corev1.ProbeHandler{HTTPGet: &corev1.HTTPGetAction{Path: "/healthz", Port: intstrFromInt(int(port))}},
+							InitialDelaySeconds: 5, PeriodSeconds: 10,
+						},
+						SecurityContext: &corev1.SecurityContext{
+							AllowPrivilegeEscalation: ptr(false),
+							ReadOnlyRootFilesystem:   ptr(true),
+							Capabilities:             &corev1.Capabilities{Drop: []corev1.Capability{"ALL"}},
+						},
+					}},
+				},
+			},
+		}
+	})
+}
+
+func (r *BindTSIGAPIReconciler) reconcileService(ctx context.Context, api *bindv1alpha1.BindTSIGAPI, _, _ string) error {
+	svc := &corev1.Service{ObjectMeta: metav1.ObjectMeta{Name: api.Name, Namespace: api.Namespace, Labels: tsigAPILabels(api.Name), Annotations: api.Spec.Service.Annotations}}
+	return r.apply(ctx, api, svc, func() {
+		port := api.Spec.Port
+		if port == 0 {
+			port = 8443
+		}
+		svcType := api.Spec.Service.Type
+		if svcType == "" {
+			svcType = corev1.ServiceTypeClusterIP
+		}
+		svc.Spec.Type = svcType
+		svc.Spec.Selector = map[string]string{"app.kubernetes.io/instance": api.Name}
+		svc.Spec.Ports = []corev1.ServicePort{{Name: "https", Port: port, TargetPort: intstrFromInt(int(port))}}
+		if api.Spec.Service.LoadBalancerIP != "" {
+			svc.Spec.LoadBalancerIP = api.Spec.Service.LoadBalancerIP
+		}
+	})
+}
+
+// apply creates or updates an owned object (in the BindTSIGAPI's namespace).
+func (r *BindTSIGAPIReconciler) apply(ctx context.Context, api *bindv1alpha1.BindTSIGAPI, obj client.Object, mutate func()) error {
+	return r.applyIn(ctx, api, obj, api.Namespace, mutate)
+}
+
+// applyIn creates or updates an object; ownership is set only for objects in
+// the BindTSIGAPI's own namespace (cross-namespace owner refs are not allowed).
+func (r *BindTSIGAPIReconciler) applyIn(ctx context.Context, api *bindv1alpha1.BindTSIGAPI, obj client.Object, namespace string, mutate func()) error {
+	key := client.ObjectKeyFromObject(obj)
+	err := r.Get(ctx, key, obj)
+	if apierrors.IsNotFound(err) {
+		mutate()
+		if namespace == api.Namespace {
+			if serr := ctrl.SetControllerReference(api, obj, r.Scheme); serr != nil {
+				return serr
+			}
+		}
+		return r.Create(ctx, obj)
+	}
+	if err != nil {
+		return err
+	}
+	mutate()
+	return r.Update(ctx, obj)
+}
+
+func (r *BindTSIGAPIReconciler) SetupWithManager(mgr ctrl.Manager) error {
+	return ctrl.NewControllerManagedBy(mgr).
+		For(&bindv1alpha1.BindTSIGAPI{}).
+		Owns(&appsv1.Deployment{}).
+		Owns(&corev1.Service{}).
+		Owns(&corev1.ConfigMap{}).
+		Owns(&corev1.ServiceAccount{}).
+		Complete(r)
+}
+
+func ptr[T any](v T) *T { return &v }

internal/controller/setup.go

@@ -35,5 +35,8 @@ func SetupAll(mgr ctrl.Manager, exec *bind.Executor) error {
 	if err := (&DNSRecordReconciler{Client: mgr.GetClient(), Scheme: mgr.GetScheme(), Exec: exec}).SetupWithManager(mgr); err != nil {
 		return err
 	}
+	if err := (&BindTSIGAPIReconciler{Client: mgr.GetClient(), Scheme: mgr.GetScheme()}).SetupWithManager(mgr); err != nil {
+		return err
+	}
 	return nil
 }

internal/tsigapi/keys.go

@@ -0,0 +1,168 @@
+package tsigapi
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	corev1 "k8s.io/api/core/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	bindv1alpha1 "git.unkin.net/unkin/bind-operator/api/v1alpha1"
+)
+
+// createKey creates a BindTSIGKey and waits for the operator to materialise it.
+func (s *Server) createKey(ctx context.Context, req createRequest) (*keyResponse, error) {
+	algorithm := req.Algorithm
+	if algorithm == "" {
+		algorithm = string(bindv1alpha1.TSIGHMACSHA256)
+	}
+	key := &bindv1alpha1.BindTSIGKey{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      req.Name,
+			Namespace: s.Namespace,
+			Labels:    map[string]string{"app.kubernetes.io/managed-by": "bind-tsig-api"},
+		},
+		Spec: bindv1alpha1.BindTSIGKeySpec{
+			Algorithm:  bindv1alpha1.TSIGAlgorithm(algorithm),
+			ClusterRef: req.ClusterRef,
+			KeyName:    req.Name,
+		},
+	}
+	if err := s.Client.Create(ctx, key); err != nil && !apierrors.IsAlreadyExists(err) {
+		return nil, fmt.Errorf("create bindtsigkey: %w", err)
+	}
+	return s.waitForMaterial(ctx, req.Name)
+}
+
+// readKey returns the current material for a key.
+func (s *Server) readKey(ctx context.Context, name string) (*keyResponse, error) {
+	var key bindv1alpha1.BindTSIGKey
+	if err := s.Client.Get(ctx, s.key(name), &key); err != nil {
+		return nil, err
+	}
+	return s.material(ctx, &key)
+}
+
+// rotateKey replaces the key material: it deletes the key Secret (the operator
+// regenerates it) and bumps a rotation annotation so the cluster controller
+// re-renders keys.conf and reloads BIND.
+func (s *Server) rotateKey(ctx context.Context, name string) (*keyResponse, error) {
+	var key bindv1alpha1.BindTSIGKey
+	if err := s.Client.Get(ctx, s.key(name), &key); err != nil {
+		return nil, err
+	}
+
+	secretName := secretNameFor(&key)
+	var secret corev1.Secret
+	if err := s.Client.Get(ctx, client.ObjectKey{Namespace: s.Namespace, Name: secretName}, &secret); err == nil {
+		if derr := s.Client.Delete(ctx, &secret); derr != nil && !apierrors.IsNotFound(derr) {
+			return nil, fmt.Errorf("delete key secret: %w", derr)
+		}
+	} else if !apierrors.IsNotFound(err) {
+		return nil, err
+	}
+
+	// Trigger re-generation + re-render by bumping the CR.
+	if key.Annotations == nil {
+		key.Annotations = map[string]string{}
+	}
+	key.Annotations[rotationAnnotation] = s.Now().UTC().Format(time.RFC3339Nano)
+	if err := s.Client.Update(ctx, &key); err != nil {
+		return nil, fmt.Errorf("bump rotation annotation: %w", err)
+	}
+
+	return s.waitForNewMaterial(ctx, name, secret.UID)
+}
+
+// deleteKey removes the BindTSIGKey (its Secret is garbage-collected).
+func (s *Server) deleteKey(ctx context.Context, name string) error {
+	key := &bindv1alpha1.BindTSIGKey{ObjectMeta: metav1.ObjectMeta{Name: name, Namespace: s.Namespace}}
+	if err := s.Client.Delete(ctx, key); err != nil && !apierrors.IsNotFound(err) {
+		return err
+	}
+	return nil
+}
+
+// material reads the key material from the Secret referenced by a BindTSIGKey.
+func (s *Server) material(ctx context.Context, key *bindv1alpha1.BindTSIGKey) (*keyResponse, error) {
+	var secret corev1.Secret
+	if err := s.Client.Get(ctx, client.ObjectKey{Namespace: s.Namespace, Name: secretNameFor(key)}, &secret); err != nil {
+		return nil, err
+	}
+	algorithm := string(secret.Data["algorithm"])
+	if algorithm == "" {
+		algorithm = string(key.Spec.Algorithm)
+	}
+	keyName := string(secret.Data["keyName"])
+	if keyName == "" {
+		keyName = key.Name
+	}
+	return &keyResponse{
+		Name:       key.Name,
+		Algorithm:  algorithm,
+		Secret:     string(secret.Data["secret"]),
+		KeyName:    keyName,
+		ClusterRef: key.Spec.ClusterRef,
+	}, nil
+}
+
+// waitForMaterial polls until the key's Secret exists (operator reconciled).
+func (s *Server) waitForMaterial(ctx context.Context, name string) (*keyResponse, error) {
+	deadline := s.Now().Add(s.WaitTimeout)
+	for {
+		var key bindv1alpha1.BindTSIGKey
+		if err := s.Client.Get(ctx, s.key(name), &key); err != nil {
+			return nil, err
+		}
+		if resp, err := s.material(ctx, &key); err == nil && resp.Secret != "" {
+			return resp, nil
+		}
+		if s.Now().After(deadline) {
+			return nil, fmt.Errorf("timed out waiting for key %q material", name)
+		}
+		select {
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		case <-time.After(250 * time.Millisecond):
+		}
+	}
+}
+
+// waitForNewMaterial polls until the Secret has been recreated (different UID).
+func (s *Server) waitForNewMaterial(ctx context.Context, name string, oldUID types.UID) (*keyResponse, error) {
+	deadline := s.Now().Add(s.WaitTimeout)
+	for {
+		var key bindv1alpha1.BindTSIGKey
+		if err := s.Client.Get(ctx, s.key(name), &key); err != nil {
+			return nil, err
+		}
+		var secret corev1.Secret
+		err := s.Client.Get(ctx, client.ObjectKey{Namespace: s.Namespace, Name: secretNameFor(&key)}, &secret)
+		if err == nil && secret.UID != oldUID && len(secret.Data["secret"]) > 0 {
+			return s.material(ctx, &key)
+		}
+		if s.Now().After(deadline) {
+			return nil, fmt.Errorf("timed out waiting for key %q to rotate", name)
+		}
+		select {
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		case <-time.After(250 * time.Millisecond):
+		}
+	}
+}
+
+// secretNameFor returns the Secret name holding a key's material.
+func secretNameFor(key *bindv1alpha1.BindTSIGKey) string {
+	if key.Status.SecretName != "" {
+		return key.Status.SecretName
+	}
+	if key.Spec.SecretName != "" {
+		return key.Spec.SecretName
+	}
+	return key.Name + "-tsig"
+}

internal/tsigapi/server.go

@@ -0,0 +1,155 @@
+// Package tsigapi implements the companion TSIG API deployed by the operator.
+// It exposes the HTTP contract consumed by vault-plugin-secrets-bind-tsig and
+// fulfils it by managing BindTSIGKey custom resources, which the operator
+// reconciles into key material.
+package tsigapi
+
+import (
+	"crypto/subtle"
+	"encoding/json"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/go-logr/logr"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+const rotationAnnotation = "bind.unkin.net/rotated-at"
+
+// Server serves the TSIG key API.
+type Server struct {
+	Client    client.Client
+	Namespace string
+	Token     string
+	Log       logr.Logger
+	// WaitTimeout bounds how long a create/rotate waits for the operator to
+	// reconcile the key material.
+	WaitTimeout time.Duration
+	// Now is injectable for tests; defaults to time.Now.
+	Now func() time.Time
+}
+
+type keyResponse struct {
+	Name       string `json:"name"`
+	Algorithm  string `json:"algorithm"`
+	Secret     string `json:"secret"`
+	KeyName    string `json:"key_name"`
+	ClusterRef string `json:"cluster_ref,omitempty"`
+}
+
+type createRequest struct {
+	Name       string `json:"name"`
+	Algorithm  string `json:"algorithm"`
+	ClusterRef string `json:"cluster_ref"`
+	Static     bool   `json:"static"`
+}
+
+// Handler returns the API's HTTP handler.
+func (s *Server) Handler() http.Handler {
+	if s.Now == nil {
+		s.Now = time.Now
+	}
+	if s.WaitTimeout == 0 {
+		s.WaitTimeout = 15 * time.Second
+	}
+	mux := http.NewServeMux()
+	mux.HandleFunc("/healthz", func(w http.ResponseWriter, _ *http.Request) { _, _ = w.Write([]byte("ok")) })
+	mux.HandleFunc("/v1/keys", s.auth(s.handleKeys))
+	mux.HandleFunc("/v1/keys/", s.auth(s.handleKey))
+	return mux
+}
+
+func (s *Server) auth(next http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if s.Token != "" {
+			want := "Bearer " + s.Token
+			got := r.Header.Get("Authorization")
+			if subtle.ConstantTimeCompare([]byte(got), []byte(want)) != 1 {
+				http.Error(w, "unauthorized", http.StatusUnauthorized)
+				return
+			}
+		}
+		next(w, r)
+	}
+}
+
+// handleKeys serves POST /v1/keys (create).
+func (s *Server) handleKeys(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+	var req createRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		http.Error(w, "invalid body", http.StatusBadRequest)
+		return
+	}
+	if req.Name == "" {
+		http.Error(w, "name is required", http.StatusBadRequest)
+		return
+	}
+	key, err := s.createKey(r.Context(), req)
+	if err != nil {
+		s.fail(w, "create", req.Name, err)
+		return
+	}
+	writeJSON(w, http.StatusOK, key)
+}
+
+// handleKey serves GET/DELETE /v1/keys/{name} and POST /v1/keys/{name}/rotate.
+func (s *Server) handleKey(w http.ResponseWriter, r *http.Request) {
+	name := strings.Trim(strings.TrimPrefix(r.URL.Path, "/v1/keys/"), "/")
+	rotate := strings.HasSuffix(name, "/rotate")
+	name = strings.TrimSuffix(name, "/rotate")
+	if name == "" {
+		http.Error(w, "key name is required", http.StatusBadRequest)
+		return
+	}
+
+	switch {
+	case rotate && r.Method == http.MethodPost:
+		key, err := s.rotateKey(r.Context(), name)
+		if err != nil {
+			s.fail(w, "rotate", name, err)
+			return
+		}
+		writeJSON(w, http.StatusOK, key)
+	case r.Method == http.MethodGet:
+		key, err := s.readKey(r.Context(), name)
+		if err != nil {
+			s.fail(w, "read", name, err)
+			return
+		}
+		writeJSON(w, http.StatusOK, key)
+	case r.Method == http.MethodDelete:
+		if err := s.deleteKey(r.Context(), name); err != nil {
+			s.fail(w, "delete", name, err)
+			return
+		}
+		w.WriteHeader(http.StatusNoContent)
+	default:
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+	}
+}
+
+func (s *Server) fail(w http.ResponseWriter, op, name string, err error) {
+	if apierrors.IsNotFound(err) {
+		http.Error(w, "not found", http.StatusNotFound)
+		return
+	}
+	s.Log.Error(err, "tsig api request failed", "op", op, "name", name)
+	http.Error(w, err.Error(), http.StatusInternalServerError)
+}
+
+func writeJSON(w http.ResponseWriter, status int, v interface{}) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	_ = json.NewEncoder(w).Encode(v)
+}
+
+func (s *Server) key(name string) types.NamespacedName {
+	return types.NamespacedName{Namespace: s.Namespace, Name: name}
+}

internal/tsigapi/server_test.go

@@ -0,0 +1,185 @@
+package tsigapi
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/go-logr/logr"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/types"
+	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/client/fake"
+
+	bindv1alpha1 "git.unkin.net/unkin/bind-operator/api/v1alpha1"
+)
+
+const testNS = "bind-system"
+
+// fakeOperator simulates the BindTSIGKey controller: whenever a key exists
+// without its material Secret, it creates one. It stops when ctx is cancelled.
+func fakeOperator(ctx context.Context, c client.Client) {
+	seq := 0
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-time.After(20 * time.Millisecond):
+		}
+		var keys bindv1alpha1.BindTSIGKeyList
+		if err := c.List(ctx, &keys); err != nil {
+			continue
+		}
+		for i := range keys.Items {
+			k := &keys.Items[i]
+			secretName := k.Name + "-tsig"
+			var existing corev1.Secret
+			if err := c.Get(ctx, client.ObjectKey{Namespace: k.Namespace, Name: secretName}, &existing); err == nil {
+				continue
+			}
+			seq++
+			material := "secret-material-" + itoa(seq)
+			_ = c.Create(ctx, &corev1.Secret{
+				// Fake client does not assign UIDs; set one so rotation
+				// (which detects a Secret with a new UID) is observable.
+				ObjectMeta: metav1.ObjectMeta{Name: secretName, Namespace: k.Namespace, UID: types.UID("uid-" + itoa(seq))},
+				Data: map[string][]byte{
+					"algorithm": []byte(k.Spec.Algorithm),
+					"keyName":   []byte(k.Name),
+					"secret":    []byte(material),
+				},
+			})
+		}
+	}
+}
+
+func itoa(n int) string {
+	if n == 0 {
+		return "0"
+	}
+	var b []byte
+	for n > 0 {
+		b = append([]byte{byte('0' + n%10)}, b...)
+		n /= 10
+	}
+	return string(b)
+}
+
+func newTestServer(t *testing.T) (*Server, context.CancelFunc) {
+	t.Helper()
+	scheme := runtime.NewScheme()
+	if err := clientgoscheme.AddToScheme(scheme); err != nil {
+		t.Fatalf("clientgo scheme: %v", err)
+	}
+	if err := bindv1alpha1.AddToScheme(scheme); err != nil {
+		t.Fatalf("bind scheme: %v", err)
+	}
+	c := fake.NewClientBuilder().WithScheme(scheme).Build()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	go fakeOperator(ctx, c)
+
+	return &Server{
+		Client:      c,
+		Namespace:   testNS,
+		Token:       "s3cr3t",
+		Log:         logr.Discard(),
+		WaitTimeout: 3 * time.Second,
+	}, cancel
+}
+
+func TestHealthzAndAuth(t *testing.T) {
+	srv, cancel := newTestServer(t)
+	defer cancel()
+	h := srv.Handler()
+
+	// healthz needs no auth.
+	rr := httptest.NewRecorder()
+	h.ServeHTTP(rr, httptest.NewRequest(http.MethodGet, "/healthz", nil))
+	if rr.Code != http.StatusOK {
+		t.Fatalf("healthz: want 200, got %d", rr.Code)
+	}
+
+	// missing token is rejected.
+	rr = httptest.NewRecorder()
+	h.ServeHTTP(rr, httptest.NewRequest(http.MethodPost, "/v1/keys", strings.NewReader(`{"name":"x"}`)))
+	if rr.Code != http.StatusUnauthorized {
+		t.Fatalf("no-auth: want 401, got %d", rr.Code)
+	}
+}
+
+func TestKeyLifecycle(t *testing.T) {
+	srv, cancel := newTestServer(t)
+	defer cancel()
+	h := srv.Handler()
+
+	// create
+	created := do(t, h, http.MethodPost, "/v1/keys", `{"name":"host-a","cluster_ref":"bind-authoritative"}`, http.StatusOK)
+	if created.Secret == "" {
+		t.Fatalf("create returned empty secret")
+	}
+	if created.ClusterRef != "bind-authoritative" {
+		t.Fatalf("cluster_ref not propagated: %q", created.ClusterRef)
+	}
+
+	// read returns the same material
+	got := do(t, h, http.MethodGet, "/v1/keys/host-a", "", http.StatusOK)
+	if got.Secret != created.Secret {
+		t.Fatalf("read secret %q != created %q", got.Secret, created.Secret)
+	}
+
+	// rotate returns new material
+	rotated := do(t, h, http.MethodPost, "/v1/keys/host-a/rotate", "", http.StatusOK)
+	if rotated.Secret == created.Secret {
+		t.Fatalf("rotate did not change secret")
+	}
+
+	// delete
+	rr := httptest.NewRecorder()
+	req := authed(http.MethodDelete, "/v1/keys/host-a", "")
+	h.ServeHTTP(rr, req)
+	if rr.Code != http.StatusNoContent {
+		t.Fatalf("delete: want 204, got %d", rr.Code)
+	}
+
+	// read after delete → 404
+	rr = httptest.NewRecorder()
+	h.ServeHTTP(rr, authed(http.MethodGet, "/v1/keys/host-a", ""))
+	if rr.Code != http.StatusNotFound {
+		t.Fatalf("read-after-delete: want 404, got %d", rr.Code)
+	}
+}
+
+func authed(method, path, body string) *http.Request {
+	var r *http.Request
+	if body == "" {
+		r = httptest.NewRequest(method, path, nil)
+	} else {
+		r = httptest.NewRequest(method, path, strings.NewReader(body))
+	}
+	r.Header.Set("Authorization", "Bearer s3cr3t")
+	return r
+}
+
+func do(t *testing.T, h http.Handler, method, path, body string, wantCode int) keyResponse {
+	t.Helper()
+	rr := httptest.NewRecorder()
+	h.ServeHTTP(rr, authed(method, path, body))
+	if rr.Code != wantCode {
+		t.Fatalf("%s %s: want %d, got %d (%s)", method, path, wantCode, rr.Code, rr.Body.String())
+	}
+	var resp keyResponse
+	if rr.Body.Len() > 0 {
+		if err := json.Unmarshal(rr.Body.Bytes(), &resp); err != nil {
+			t.Fatalf("decode response: %v", err)
+		}
+	}
+	return resp
+}