refactor(aws): simplify adjustOtherRecord with clarifying comment

Signed-off-by: u-kai <76635578+u-kai@users.noreply.github.com>

Author: u-kai

provider/aws/aws.go

@@ -898,22 +898,13 @@ func (p *AWSProvider) adjustCNAMERecord(ep *endpoint.Endpoint) {
 	}
 }
 
-// See: https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/resource-record-sets-values-alias.html
 func (p *AWSProvider) adjustOtherRecord(ep *endpoint.Endpoint) {
-	// NS and SOA records do not support alias
-	if ep.RecordType == endpoint.RecordTypeNS || ep.RecordType == "SOA" {
-		ep.DeleteProviderSpecificProperty(providerSpecificAlias)
-		ep.DeleteProviderSpecificProperty(providerSpecificEvaluateTargetHealth)
-		return
-	}
-	// All other record types support alias when pointing to another record in the same hosted zone
-	isAlias, _ := ep.GetBoolProviderSpecificProperty(providerSpecificAlias)
-	if isAlias {
-		p.adjustAliasRecord(ep)
-	} else {
-		ep.DeleteProviderSpecificProperty(providerSpecificAlias)
-		ep.DeleteProviderSpecificProperty(providerSpecificEvaluateTargetHealth)
-	}
+	// Although Route53 supports alias records for all types except NS and SOA
+	// (see: https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/resource-record-sets-values-alias.html),
+	// ExternalDNS only uses alias for A/AAAA records converted from CNAME.
+	// For other record types, we simply remove the alias-related properties.
+	ep.DeleteProviderSpecificProperty(providerSpecificAlias)
+	ep.DeleteProviderSpecificProperty(providerSpecificEvaluateTargetHealth)
 }
 
 // if the endpoint is using geoproximity, set the bias to 0 if not set

provider/aws/aws_test.go

@@ -3324,7 +3324,7 @@ func TestAWSProvider_adjustEndpointAndNewAaaaIfNeeded(t *testing.T) {
 			expectedAaaa: nil,
 		},
 		{
-			name: "MX record with alias=true should be treated as alias and not create AAAA",
+			name: "MX record with alias-related properties should drop them, keep ttl and not create AAAA",
 			ep: &endpoint.Endpoint{
 				DNSName:    "test.foo.bar.",
 				RecordType: endpoint.RecordTypeMX,
@@ -3341,42 +3341,6 @@ func TestAWSProvider_adjustEndpointAndNewAaaaIfNeeded(t *testing.T) {
 					},
 				},
 			},
-			expected: &endpoint.Endpoint{
-				DNSName:    "test.foo.bar.",
-				RecordType: endpoint.RecordTypeMX,
-				Targets:    endpoint.Targets{"10 mail.example.com."},
-				RecordTTL:  300,
-				ProviderSpecific: endpoint.ProviderSpecific{
-					{
-						Name:  providerSpecificAlias,
-						Value: "true",
-					},
-					{
-						Name:  providerSpecificEvaluateTargetHealth,
-						Value: "true",
-					},
-				},
-			},
-			expectedAaaa: nil,
-		},
-		{
-			name: "MX record with alias=false should drop alias properties and not create AAAA",
-			ep: &endpoint.Endpoint{
-				DNSName:    "test.foo.bar.",
-				RecordType: endpoint.RecordTypeMX,
-				Targets:    endpoint.Targets{"10 mail.example.com."},
-				RecordTTL:  600,
-				ProviderSpecific: endpoint.ProviderSpecific{
-					{
-						Name:  providerSpecificAlias,
-						Value: "false",
-					},
-					{
-						Name:  providerSpecificEvaluateTargetHealth,
-						Value: "true",
-					},
-				},
-			},
 			expected: &endpoint.Endpoint{
 				DNSName:          "test.foo.bar.",
 				RecordType:       endpoint.RecordTypeMX,
@@ -3386,33 +3350,6 @@ func TestAWSProvider_adjustEndpointAndNewAaaaIfNeeded(t *testing.T) {
 			},
 			expectedAaaa: nil,
 		},
-
-		// --- NS records ---
-		{
-			name: "NS record with alias=true should drop alias properties since NS does not support alias",
-			ep: &endpoint.Endpoint{
-				DNSName:    "test.foo.bar.",
-				RecordType: endpoint.RecordTypeNS,
-				Targets:    endpoint.Targets{"ns1.example.com."},
-				ProviderSpecific: endpoint.ProviderSpecific{
-					{
-						Name:  providerSpecificAlias,
-						Value: "true",
-					},
-					{
-						Name:  providerSpecificEvaluateTargetHealth,
-						Value: "true",
-					},
-				},
-			},
-			expected: &endpoint.Endpoint{
-				DNSName:          "test.foo.bar.",
-				RecordType:       endpoint.RecordTypeNS,
-				Targets:          endpoint.Targets{"ns1.example.com."},
-				ProviderSpecific: endpoint.ProviderSpecific{},
-			},
-			expectedAaaa: nil,
-		},
 	}
 
 	for _, tt := range tests {