fix: should update dns label if target pip already have one and its v…

…alue is different

Signed-off-by: MartinForReal <fanshangxiang@gmail.com>

pkg/provider/azure_loadbalancer.go

@@ -1191,7 +1191,8 @@ func reconcileDNSSettings(pip *network.PublicIPAddress, domainNameLabel, service
 		} else {
 			existingDNSLabel := pip.PublicIPAddressPropertiesFormat.DNSSettings.DomainNameLabel
 			if !strings.EqualFold(to.String(existingDNSLabel), domainNameLabel) {
-				return false, fmt.Errorf("ensurePublicIPExists for service(%s): pip(%s) - there is an existing DNS label %s on the public IP", serviceName, pipName, *existingDNSLabel)
+				pip.PublicIPAddressPropertiesFormat.DNSSettings.DomainNameLabel = &domainNameLabel
+				changed = true
 			}
 		}
 

pkg/provider/azure_loadbalancer_test.go

@@ -4192,6 +4192,34 @@ func TestEnsurePublicIPExists(t *testing.T) {
 			},
 			shouldPutPIP: true,
 		},
+		{
+			desc:                    "shall update existed PIP's dns label for IPv6",
+			inputDNSLabel:           "newdns",
+			foundDNSLabelAnnotation: true,
+			isIPv6:                  true,
+			existingPIPs: []network.PublicIPAddress{{
+
+				Name: to.StringPtr("pip1"),
+				PublicIPAddressPropertiesFormat: &network.PublicIPAddressPropertiesFormat{
+					DNSSettings: &network.PublicIPAddressDNSSettings{
+						DomainNameLabel: to.StringPtr("previousdns"),
+					},
+				},
+			}},
+			expectedPIP: &network.PublicIPAddress{
+				Name: to.StringPtr("pip1"),
+				ID: to.StringPtr("/subscriptions/subscription/resourceGroups/rg" +
+					"/providers/Microsoft.Network/publicIPAddresses/pip1"),
+				PublicIPAddressPropertiesFormat: &network.PublicIPAddressPropertiesFormat{
+					DNSSettings: &network.PublicIPAddressDNSSettings{
+						DomainNameLabel: to.StringPtr("newdns"),
+					},
+					PublicIPAllocationMethod: "Dynamic",
+					PublicIPAddressVersion:   "IPv6",
+				},
+			},
+			shouldPutPIP: true,
+		},
 		{
 			desc:                    "shall report an conflict error if the DNS label is conflicted",
 			inputDNSLabel:           "test",