refactor(multicluster): Replace use of unstructured API with typed bi…

…ndings for Link CR (#13420)

The linkerd-multicluster extension uses client-go's `unstructured` API to access Link custom resources.  This API allowed us to develop quickly without the work of generating typed bindings.  However, using the unstrucutred API is error prone since fields must be accessed by their string name.  It is also inconsistent with the rest of the project which uses typed bindings.

We replace the use of the unstructured API for Link resources with generated typed bindings.  The client-go APIs are slightly different and client-go does not provide a way to update subresources for typed bindings.  Therefore, when updating a Link's status subresource, we use a patch instead of an update.

Signed-off-by: Alex Leong <[email protected]>

bin/update-codegen.sh

@@ -20,11 +20,10 @@ git clone --depth 1 --branch "$GEN_VER" https://github.com/kubernetes/code-gener
 rm -rf "${SCRIPT_ROOT}/controller/gen/client/clientset/*"
 rm -rf "${SCRIPT_ROOT}/controller/gen/client/listeners/*"
 rm -rf "${SCRIPT_ROOT}/controller/gen/client/informers/*"
-crds=(serviceprofile:v1alpha2 server:v1beta1 serverauthorization:v1beta1 link:v1alpha1 policy:v1alpha1 policy:v1beta3 externalworkload:v1beta1)
+crds=(serviceprofile server serverauthorization link policy policy externalworkload)
 for crd in "${crds[@]}"
 do
-  crd_path=$(tr : / <<< "$crd")
-  rm -f "${SCRIPT_ROOT}/controller/gen/apis/${crd_path}/zz_generated.deepcopy.go"
+  rm -f "${SCRIPT_ROOT}"/controller/gen/apis/"${crd}"/*/zz_generated.deepcopy.go
 done
 
 # shellcheck disable=SC1091

controller/gen/apis/link/v1alpha1/types.go

@@ -37,13 +37,16 @@ type LinkSpec struct {
 	GatewayIdentity               string               `json:"gatewayIdentity,omitempty"`
 	ProbeSpec                     ProbeSpec            `json:"probeSpec,omitempty"`
 	Selector                      metav1.LabelSelector `json:"selector,omitempty"`
+	RemoteDiscoverySelector       metav1.LabelSelector `json:"remoteDiscoverySelector,omitempty"`
 }
 
 // ProbeSpec for gateway health probe
 type ProbeSpec struct {
-	Path   string `json:"path,omitempty"`
-	Port   string `json:"port,omitempty"`
-	Period string `json:"period,omitempty"`
+	Path             string `json:"path,omitempty"`
+	Port             string `json:"port,omitempty"`
+	Period           string `json:"period,omitempty"`
+	Timeout          string `json:"timeout,omitempty"`
+	FailureThreshold string `json:"failureThreshold,omitempty"`
 }
 
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object

controller/gen/apis/link/v1alpha2/doc.go

@@ -0,0 +1,3 @@
+// +k8s:deepcopy-gen=package
+
+package v1alpha2

controller/gen/apis/link/v1alpha2/register.go

@@ -0,0 +1,48 @@
+package v1alpha2
+
+import (
+	"github.com/linkerd/linkerd2/controller/gen/apis/link"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+var (
+	// SchemeGroupVersion is the identifier for the API which includes the name
+	// of the group and the version of the API.
+	SchemeGroupVersion = schema.GroupVersion{
+		Group:   link.GroupName,
+		Version: "v1alpha2",
+	}
+
+	// SchemeBuilder collects functions that add things to a scheme. It's to
+	// allow code to compile without explicitly referencing generated types.
+	// You should declare one in each package that will have generated deep
+	// copy or conversion functions.
+	SchemeBuilder = runtime.NewSchemeBuilder(addKnownTypes)
+
+	// AddToScheme applies all the stored functions to the scheme. A non-nil error
+	// indicates that one function failed and the attempt was abandoned.
+	AddToScheme = SchemeBuilder.AddToScheme
+)
+
+// Kind takes an unqualified kind and returns back a Group qualified GroupKind
+func Kind(kind string) schema.GroupKind {
+	return SchemeGroupVersion.WithKind(kind).GroupKind()
+}
+
+// Resource takes an unqualified resource and returns a Group qualified
+// GroupResource
+func Resource(resource string) schema.GroupResource {
+	return SchemeGroupVersion.WithResource(resource).GroupResource()
+}
+
+// Adds the list of known types to Scheme.
+func addKnownTypes(scheme *runtime.Scheme) error {
+	scheme.AddKnownTypes(SchemeGroupVersion,
+		&Link{},
+		&LinkList{},
+	)
+	metav1.AddToGroupVersion(scheme, SchemeGroupVersion)
+	return nil
+}

controller/gen/apis/link/v1alpha2/types.go

@@ -0,0 +1,110 @@
+package v1alpha2
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// +genclient
+// +genclient:noStatus
+// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
+// +groupName=multicluster.linkerd.io
+
+type Link struct {
+	// TypeMeta is the metadata for the resource, like kind and apiversion
+	metav1.TypeMeta `json:",inline"`
+
+	// ObjectMeta contains the metadata for the particular object, including
+	// things like...
+	//  - name
+	//  - namespace
+	//  - self link
+	//  - labels
+	//  - ... etc ...
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	// Spec is the custom resource spec
+	Spec LinkSpec `json:"spec"`
+
+	// Status defines the current state of a Link
+	Status LinkStatus `json:"status,omitempty"`
+}
+
+// LinkSpec specifies a LinkSpec resource.
+type LinkSpec struct {
+	TargetClusterName             string                `json:"targetClusterName,omitempty"`
+	TargetClusterDomain           string                `json:"targetClusterDomain,omitempty"`
+	TargetClusterLinkerdNamespace string                `json:"targetClusterLinkerdNamespace,omitempty"`
+	ClusterCredentialsSecret      string                `json:"clusterCredentialsSecret,omitempty"`
+	GatewayAddress                string                `json:"gatewayAddress,omitempty"`
+	GatewayPort                   string                `json:"gatewayPort,omitempty"`
+	GatewayIdentity               string                `json:"gatewayIdentity,omitempty"`
+	ProbeSpec                     ProbeSpec             `json:"probeSpec,omitempty"`
+	Selector                      *metav1.LabelSelector `json:"selector,omitempty"`
+	RemoteDiscoverySelector       *metav1.LabelSelector `json:"remoteDiscoverySelector,omitempty"`
+	FederatedServiceSelector      *metav1.LabelSelector `json:"federatedServiceSelector,omitempty"`
+}
+
+// ProbeSpec for gateway health probe
+type ProbeSpec struct {
+	Path             string `json:"path,omitempty"`
+	Port             string `json:"port,omitempty"`
+	Period           string `json:"period,omitempty"`
+	Timeout          string `json:"timeout,omitempty"`
+	FailureThreshold string `json:"failureThreshold,omitempty"`
+}
+
+// LinkStatus holds information about the status services mirrored with this
+// Link.
+type LinkStatus struct {
+	// +optional
+	MirrorServices []ServiceStatus `json:"mirrorServices,omitempty"`
+	// +optional
+	FederatedServices []ServiceStatus `json:"federatedServices,omitempty"`
+}
+
+type ServiceStatus struct {
+	Conditions     []LinkCondition `json:"conditions,omitempty"`
+	ControllerName string          `json:"controllerName,omitempty"`
+	RemoteRef      ObjectRef       `json:"remoteRef,omitempty"`
+}
+
+// LinkCondition represents the service state of an ExternalWorkload
+type LinkCondition struct {
+	// Type of the condition
+	Type string `json:"type"`
+	// Status of the condition.
+	// Can be True, False, Unknown
+	Status metav1.ConditionStatus `json:"status"`
+	// Last time an ExternalWorkload was probed for a condition.
+	// +optional
+	LastProbeTime metav1.Time `json:"lastProbeTime,omitempty"`
+	// Last time a condition transitioned from one status to another.
+	// +optional
+	LastTransitionTime metav1.Time `json:"lastTransitionTime,omitempty"`
+	// Unique one word reason in CamelCase that describes the reason for a
+	// transition.
+	// +optional
+	Reason string `json:"reason,omitempty"`
+	// Human readable message that describes details about last transition.
+	// +optional
+	Message string `json:"message"`
+	// LocalRef is a reference to the local mirror or federated service.
+	LocalRef ObjectRef `json:"localRef,omitempty"`
+}
+
+type ObjectRef struct {
+	Group     string `json:"group,omitempty"`
+	Kind      string `json:"kind,omitempty"`
+	Name      string `json:"name,omitempty"`
+	Namespace string `json:"namespace,omitempty"`
+}
+
+// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
+
+// LinkList is a list of LinkList resources.
+type LinkList struct {
+	metav1.TypeMeta `json:",inline"`
+	metav1.ListMeta `json:"metadata"`
+
+	Items []Link `json:"items"`
+}