refactoring

Author: cbarbian-sap

pkg/component/component.go

@@ -15,7 +15,7 @@ import (
 )
 
 // Instantiate given Component type T; panics unless T is a pointer type.
-func newComponent[T Component]() Component {
+func newComponent[T Component]() T {
 	var component T
 	v := reflect.ValueOf(&component).Elem()
 	v.Set(reflect.New(v.Type().Elem()))

pkg/component/reconcile.go

@@ -13,10 +13,9 @@ import (
 )
 
 // Component is the central interface that component operators have to implement.
-// Besides being a conroller-runtime client.Object, the implementing type has to include
-// the Spec and Status structs defined in this package, and has to define according accessor methods,
-// called GetComponentSpec() and GetComponentStatus(). In addition it has to expose its whole spec and status
-// as Unstructurable objects, via methods GetSpec() and GetStatus().
+// Besides being a conroller-runtime client.Object, the implementing type has to expose accessor
+// methods for the deployment's target namespace and name, and for the components's spec and status.
+// via methods GetSpec() and GetStatus().
 type Component interface {
 	client.Object
 	// Return target namespace for the component deployment.
@@ -26,10 +25,10 @@ type Component interface {
 	// Return target name for the component deployment.
 	// This is the value that will be passed to Generator.Generator() as name.
 	GetDeploymentName() string
-	// Return a pointer accessor to the component's spec.
+	// Return a read-only accessor to the component's spec.
 	// Which, as a consequence, obviously has to implement the types.Unstructurable interface.
 	GetSpec() types.Unstructurable
-	// Return a pointer accessor to the component's status,
+	// Return a read-write (usually a pointer) accessor to the component's status,
 	// resp. to the corresponding sub-struct if the status extends component.Status.
 	GetStatus() *Status
 }

pkg/component/types.go

@@ -20,5 +20,7 @@ type Operator interface {
 	InitFlags(flagset *flag.FlagSet)
 	ValidateFlags() error
 	GetUncacheableTypes() []client.Object
+	// Deprecation warning: the parameter discoveryClient will be removed;
+	// implementations should not use it, and build a discoveryClient from mgr.GetConfig() and mgr.GetHTTPClient() instead.
 	Setup(mgr ctrl.Manager, discoveryClient discovery.DiscoveryInterface) error
 }

pkg/operator/types.go

@@ -36,7 +36,6 @@ import (
 	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
-	"k8s.io/client-go/discovery"
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	apiregistrationv1 "k8s.io/kube-aggregator/pkg/apis/apiregistration/v1"
 	ctrl "sigs.k8s.io/controller-runtime"
@@ -170,13 +169,7 @@ func main() {
 	//   connect to the conversion endpoint.
 	// mgr.GetWebhookServer().Register("/convert", conversion.NewWebhookHandler(mgr.GetScheme()))
 
-	discoveryClient, err := discovery.NewDiscoveryClientForConfig(mgr.GetConfig())
-	if err != nil {
-		setupLog.Error(err, "error creating discovery client")
-		os.Exit(1)
-	}
-
-	if err := operator.Setup(mgr, discoveryClient); err != nil {
+	if err := operator.Setup(mgr, nil); err != nil {
 		setupLog.Error(err, "error registering controller with manager")
 		os.Exit(1)
 	}

scaffold/templates/main.go.tpl

@@ -118,10 +118,10 @@ func (o *Operator) Setup(mgr ctrl.Manager, discoveryClient discovery.DiscoveryIn
 
 	if err := component.NewReconciler[*operator{{ .groupVersion }}.{{ .kind }}](
 		o.options.Name,
-		mgr.GetClient(),
-		discoveryClient,
-		mgr.GetEventRecorderFor(o.options.Name),
-		mgr.GetScheme(),
+		nil,
+		nil,
+		nil,
+		nil,
 		resourceGenerator,
 	).SetupWithManager(mgr); err != nil {
 		return errors.Wrapf(err, "unable to create controller")