Add multicluster.ErrClusterNotFound for providers

On-behalf-of: SAP <[email protected]>
Signed-off-by: Marvin Beckers <[email protected]>

Author: embik

pkg/multicluster/errors.go

@@ -0,0 +1,29 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package multicluster
+
+import (
+	"errors"
+)
+
+var (
+	// ErrClusterNotFound can be returned by provider implementations if the cluster requested
+	// doesn't exist and cannot be constructed.
+	ErrClusterNotFound = errClusterNotFound()
+)
+
+func errClusterNotFound() error { return errors.New("cluster not found") }

pkg/multicluster/multicluster.go

@@ -54,7 +54,7 @@ type Provider interface {
 	// Get returns a cluster for the given identifying cluster name. Get
 	// returns an existing cluster if it has been created before.
 	// If no cluster is known to the provider under the given cluster name,
-	// an error should be returned.
+	// ErrClusterNotFound should be returned.
 	Get(ctx context.Context, clusterName string) (cluster.Cluster, error)
 
 	// IndexField indexes the given object by the given field on all engaged