utils.go

// Copyright (c) 2021 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 dnsrecord

import (
	"strings"
)

const (
	// metaRecordPrefix is the prefix of meta DNS records that may exist if the shoot was previously reconciled
	// with the dns-external controller.
	metaRecordPrefix = "comment-"
)

// MatchesDomain returns true if the given name matches (is a subdomain) of the given domain, false otherwise.
func MatchesDomain(name, domain string) bool {
	return strings.HasSuffix(name, "."+domain) || domain == name
}

// FindZoneForName returns the zone ID for the longest zone domain from the given zones map that is matched by the given name.
// If the given name doesn't match any of the zone domains in the given zones map, an empty string is returned.
func FindZoneForName(zones map[string]string, name string) string {
	longestZoneName, result := "", ""
	for zoneName, zoneId := range zones {
		if MatchesDomain(name, zoneName) && len(zoneName) > len(longestZoneName) {
			longestZoneName, result = zoneName, zoneId
		}
	}
	return result
}

// GetMetaRecordName returns the meta record name for the given name.
func GetMetaRecordName(name string) string {
	if strings.HasPrefix(name, "*.") {
		return "*." + metaRecordPrefix + name[2:]
	}
	return metaRecordPrefix + name
}