Change StatusReason for invalid requests from StatusReasonForbidden t…

…o StatusReasonInvalid

This PR changes the StatusReason from StatusReasonForbidden to StatusReasonInvalid when handling invalid requests in `hncconfig.go`. To show the custom error message when the request is invalid, we need to add the message in the `Status.Details` field.

Issue: kubernetes-retired#411

incubator/hnc/pkg/validators/hierarchy.go

@@ -428,14 +428,33 @@ func allow(msg string) admission.Response {
 // human-readable message _and_ a machine-readable reason, and also sets the code correctly instead
 // of hardcoding it to 403 Forbidden.
 func deny(reason metav1.StatusReason, msg string) admission.Response {
-	return admission.Response{AdmissionResponse: admissionv1beta1.AdmissionResponse{
-		Allowed: false,
-		Result: &metav1.Status{
-			Code:    codeFromReason(reason),
-			Message: msg,
-			Reason:  reason,
-		},
-	}}
+	if reason != metav1.StatusReasonInvalid {
+		return admission.Response{AdmissionResponse: admissionv1beta1.AdmissionResponse{
+			Allowed: false,
+			Result: &metav1.Status{
+				Code:    codeFromReason(reason),
+				Message: msg,
+				Reason:  reason,
+			},
+		}}
+	} else {
+		// metav1.StatusReasonInvalid shows the custom message in the Details field instead of
+		// Message field of metav1.Status.
+		return admission.Response{AdmissionResponse: admissionv1beta1.AdmissionResponse{
+			Allowed: false,
+			Result: &metav1.Status{
+				Code:   codeFromReason(reason),
+				Reason: reason,
+				Details: &metav1.StatusDetails{
+					Causes: []metav1.StatusCause{
+						{
+							Message: msg,
+						},
+					},
+				},
+			},
+		}}
+	}
 }
 
 // codeFromReason implements the needed subset of

incubator/hnc/pkg/validators/hncconfig.go

@@ -74,7 +74,7 @@ func (c *HNCConfig) Handle(ctx context.Context, req admission.Request) admission
 // allowing it to be more easily unit tested (ie without constructing a full admission.Request).
 func (c *HNCConfig) handle(ctx context.Context, inst *api.HNCConfiguration) admission.Response {
 	if inst.GetName() != "config" {
-		return deny(metav1.StatusReasonForbidden, fmt.Sprintf("Wrong singleton name: %s; the name should be 'config'", inst.GetName()))
+		return deny(metav1.StatusReasonInvalid, fmt.Sprintf("Wrong singleton name: %s; the name should be 'config'", inst.GetName()))
 	}
 
 	roleExist := false
@@ -102,10 +102,10 @@ func (c *HNCConfig) handle(ctx context.Context, inst *api.HNCConfiguration) admi
 		}
 	}
 	if !roleExist {
-		return deny(metav1.StatusReasonForbidden, "Configuration for Role is missing")
+		return deny(metav1.StatusReasonInvalid, "Configuration for Role is missing")
 	}
 	if !roleBindingExist {
-		return deny(metav1.StatusReasonForbidden, "Configuration for RoleBinding is missing")
+		return deny(metav1.StatusReasonInvalid, "Configuration for RoleBinding is missing")
 	}
 	return allow("")
 }
@@ -114,7 +114,7 @@ func (c *HNCConfig) handle(ctx context.Context, inst *api.HNCConfiguration) admi
 func (c *HNCConfig) isTypeConfigured(t api.TypeSynchronizationSpec, ts gvkSet) admission.Response {
 	gvk := schema.FromAPIVersionAndKind(t.APIVersion, t.Kind)
 	if exists := ts[gvk]; exists {
-		return deny(metav1.StatusReasonForbidden, fmt.Sprintf("Duplicate configurations for %s", gvk))
+		return deny(metav1.StatusReasonInvalid, fmt.Sprintf("Duplicate configurations for %s", gvk))
 	}
 	ts[gvk] = true
 	return allow("")
@@ -129,7 +129,7 @@ func (c *HNCConfig) validateRBAC(mode api.SynchronizationMode, kind string) admi
 	if mode == api.Propagate || mode == "" {
 		return allow("")
 	}
-	return deny(metav1.StatusReasonForbidden, fmt.Sprintf("Invalid mode of %s; current mode: %s; expected mode %s", kind, mode, api.Propagate))
+	return deny(metav1.StatusReasonInvalid, fmt.Sprintf("Invalid mode of %s; current mode: %s; expected mode %s", kind, mode, api.Propagate))
 }
 
 // validateType validates a non-RBAC type.
@@ -138,7 +138,7 @@ func (c *HNCConfig) validateType(ctx context.Context, t api.TypeSynchronizationS
 
 	// Validate if the GVK exists in the apiserver.
 	if err := c.validator.Exists(ctx, gvk); err != nil {
-		return deny(metav1.StatusReasonForbidden,
+		return deny(metav1.StatusReasonInvalid,
 			fmt.Sprintf("Cannot find the %s in the apiserver with error: %s", gvk, err.Error()))
 	}
 
@@ -147,7 +147,7 @@ func (c *HNCConfig) validateType(ctx context.Context, t api.TypeSynchronizationS
 	case api.Propagate, api.Ignore, api.Remove, "":
 		return allow("")
 	default:
-		return deny(metav1.StatusReasonForbidden, fmt.Sprintf("Unrecognized mode '%s' for %s", t.Mode, gvk))
+		return deny(metav1.StatusReasonInvalid, fmt.Sprintf("Unrecognized mode '%s' for %s", t.Mode, gvk))
 	}
 }