/
nodename.go
43 lines (38 loc) · 1.73 KB
/
nodename.go
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// Copyright 2023 SAP SE or an SAP affiliate company. All rights reserved. This file is licensed under the Apache Software License, v. 2 except as noted otherwise in the LICENSE file
//
// 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 nodeagent
import (
"context"
"fmt"
corev1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"sigs.k8s.io/controller-runtime/pkg/client"
)
// FetchNodeByHostName tries to fetch the node (metadata-only) object based on the hostname.
func FetchNodeByHostName(ctx context.Context, c client.Client, hostName string) (*metav1.PartialObjectMetadata, error) {
// node name not known yet, try to fetch it via label selector based on hostname
nodeList := &metav1.PartialObjectMetadataList{}
nodeList.SetGroupVersionKind(corev1.SchemeGroupVersion.WithKind("NodeList"))
if err := c.List(ctx, nodeList, client.MatchingLabels{corev1.LabelHostname: hostName}); err != nil {
return nil, fmt.Errorf("unable to list nodes with label selector %s=%s: %w", corev1.LabelHostname, hostName, err)
}
switch len(nodeList.Items) {
case 0:
return nil, nil
case 1:
return &nodeList.Items[0], nil
default:
return nil, fmt.Errorf("found more than one node with label %s=%s", corev1.LabelHostname, hostName)
}
}