feat: add XPostCreateTarget interface for post-creation target custom…

api/xset_controller_types.go

@@ -137,3 +137,12 @@ type DecorationAdapter interface {
 type TargetPrefixGetter interface {
 	GetTargetPrefix(xset XSetObject) string
 }
+
+// XPostCreateTarget is an optional interface that XSetController can implement
+// to apply additional modifications to targets after their names are assigned
+// (e.g., setting pod hostname based on the pod name).
+// The functions returned by GetXPostCreateTargetFuncs are called after the target
+// object is constructed but before it is created on the API server.
+type XPostCreateTarget interface {
+	GetXPostCreateTargetFuncs(revision *appsv1.ControllerRevision) []func(client.Object) error
+}

synccontrols/sync_control.go

@@ -562,6 +562,14 @@ func (r *RealSyncControl) Scale(ctx context.Context, xsetObject api.XSetObject,
 				if err != nil {
 					return apierrors.NewInvalid(schema.GroupKind{Group: r.targetGVK.Group, Kind: r.targetGVK.Kind}, target.GetGenerateName(), []*field.Error{{Detail: err.Error()}})
 				}
+				// apply post-create target funcs (e.g., set pod hostname based on pod name)
+				if postCreateAdapter, ok := r.xsetController.(api.XPostCreateTarget); ok {
+					for _, fn := range postCreateAdapter.GetXPostCreateTargetFuncs(revision) {
+						if err = fn(target); err != nil {
+							return fmt.Errorf("fail to apply post-create target func for target %s: %w", target.GetName(), err)
+						}
+					}
+				}
 				// create subresources for targets
 				if r.subResourceControl != nil {
 					if err = r.subResourceControl.CreateTargetResources(ctx, xsetObject, target, syncContext.ExistingSubResources); err != nil {

synccontrols/x_replace.go

@@ -172,6 +172,15 @@ func (r *RealSyncControl) replaceOriginTargets(
 			return err
 		}
 
+		// apply post-create target funcs (e.g., set pod hostname based on pod name)
+		if postCreateAdapter, ok := r.xsetController.(api.XPostCreateTarget); ok {
+			for _, fn := range postCreateAdapter.GetXPostCreateTargetFuncs(replaceRevision) {
+				if err = fn(newTarget); err != nil {
+					return fmt.Errorf("fail to apply post-create target func for replace target %s: %w", newTarget.GetName(), err)
+				}
+			}
+		}
+
 		r.xsetLabelAnnoMgr.Set(newTarget, api.XReplacePairOriginName, originTarget.GetName())
 		r.xsetLabelAnnoMgr.Set(newTarget, api.XCreatingLabel, strconv.FormatInt(time.Now().UnixNano(), 10))
 		r.resourceContextControl.Put(newTargetContext, api.EnumRevisionContextDataKey, replaceRevision.GetName())