🐛 surface controller options when using builder

Fixes: #317

- Currently there is no way to override MaxConcurrentReconciles using builder
- Provide a method to override controller options
- Another approach was to provide MaxConcurrentReconciles itself, but it isnt future proof incase additional options are added

Author: awesomenix

pkg/builder/controller.go

@@ -47,6 +47,7 @@ type Builder struct {
 	watchRequest   []watchRequest
 	config         *rest.Config
 	ctrl           controller.Controller
+	ctrlOptions    controller.Options
 	name           string
 }
 
@@ -125,6 +126,12 @@ func (blder *Builder) WithEventFilter(p predicate.Predicate) *Builder {
 	return blder
 }
 
+// WithOptions overrides the controller options use in doController. Defaults to empty.
+func (blder *Builder) WithOptions(options controller.Options) *Builder {
+	blder.ctrlOptions = options
+	return blder
+}
+
 // Named sets the name of the controller to the given name.  The name shows up
 // in metrics, among other things, and thus should be a prometheus compatible name
 // (underscores and alphanumeric characters only).
@@ -241,6 +248,8 @@ func (blder *Builder) doController(r reconcile.Reconciler) error {
 	if err != nil {
 		return err
 	}
-	blder.ctrl, err = newController(name, blder.mgr, controller.Options{Reconciler: r})
+	ctrlOptions := blder.ctrlOptions
+	ctrlOptions.Reconciler = r
+	blder.ctrl, err = newController(name, blder.mgr, ctrlOptions)
 	return err
 }

pkg/builder/controller_test.go

@@ -121,6 +121,24 @@ var _ = Describe("application", func() {
 			Expect(instance).To(BeNil())
 		})
 
+		It("should override max concurrent reconcilers during creation of controller", func() {
+			const maxConcurrentReconciles = 5
+			newController = func(name string, mgr manager.Manager, options controller.Options) (
+				controller.Controller, error) {
+				if options.MaxConcurrentReconciles == maxConcurrentReconciles {
+					return controller.New(name, mgr, options)
+				}
+				return nil, fmt.Errorf("max concurrent reconcilers expected %d but found %d", maxConcurrentReconciles, options.MaxConcurrentReconciles)
+			}
+			instance, err := SimpleController().
+				For(&appsv1.ReplicaSet{}).
+				Owns(&appsv1.ReplicaSet{}).
+				WithOptions(controller.Options{MaxConcurrentReconciles: maxConcurrentReconciles}).
+				Build(noop)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(instance).NotTo(BeNil())
+		})
+
 		It("should allow multiple controllers for the same kind", func() {
 			By("creating a controller manager")
 			m, err := manager.New(cfg, manager.Options{})