only one address under domain should skip release

this strategy only suitable for MySQL

dbm-services/common/dbha/ha-module/client/name_service.go

@@ -68,6 +68,32 @@ func (c *NameServiceClient) GetDomainInfoByIp(ip string) ([]DomainInfo, error) {
 	return res.Detail, nil
 }
 
+// GetAddressNumberByDomain get address number under this domain name
+func (c *NameServiceClient) GetAddressNumberByDomain(domainName string) (int, error) {
+	var res DomainRes
+	req := map[string]interface{}{
+		"db_cloud_token": c.Conf.BKConf.BkToken,
+		"bk_cloud_id":    c.CloudId,
+		"domain_name":    []string{domainName},
+	}
+
+	response, err := c.DoNew(http.MethodPost,
+		c.SpliceUrlByPrefix(c.Conf.UrlPre, constvar.GetDomainInfoUrl, ""), req, nil)
+	if err != nil {
+		return 0, err
+	}
+	if response.Code != 0 {
+		return 0, fmt.Errorf("%s failed, return code:%d, msg:%s", util.AtWhere(), response.Code, response.Msg)
+	}
+
+	err = json.Unmarshal(response.Data, &res)
+	if err != nil {
+		return 0, err
+	}
+
+	return res.RowsNum, nil
+}
+
 // GetDomainInfoByDomain get address info from dns by domain
 func (c *NameServiceClient) GetDomainInfoByDomain(domainName string) ([]DomainInfo, error) {
 	var res DomainRes

dbm-services/common/dbha/ha-module/dbmodule/dbmysql/MySQLProxy_switch.go

@@ -22,8 +22,20 @@ func (ins *MySQLProxySwitch) CheckSwitch() (bool, error) {
 // DoSwitch mysql-proxy do switch
 // delete ip under the entry
 func (ins *MySQLProxySwitch) DoSwitch() error {
-	ins.ReportLogs(constvar.InfoResult, fmt.Sprintf("try to release ip[%s] from all cluster entery", ins.Ip))
-	return ins.DeleteNameService(ins.Entry)
+	//1. delete name service
+	isSingle, err := ins.SingleAddressUnderDomain(ins.Entry)
+	if err != nil {
+		ins.ReportLogs(constvar.FailResult, fmt.Sprintf("check whether single address under domain failed:%s",
+			err.Error()))
+		return err
+	}
+	if isSingle {
+		return fmt.Errorf("only single address under this domain, skip release domain")
+	} else {
+		ins.ReportLogs(constvar.InfoResult, fmt.Sprintf("try to release ip[%s#%d] from all cluster entry",
+			ins.Ip, ins.Port))
+		return ins.DeleteNameService(ins.Entry)
+	}
 }
 
 // ShowSwitchInstanceInfo display switch proxy info

dbm-services/common/dbha/ha-module/dbmodule/dbmysql/MySQL_common_switch.go

@@ -229,14 +229,14 @@ type TdbctlNodes struct {
 	ReplicationInfo   string `gorm:"column:REPLICATION_INFO;NOT NULL"`
 }
 
-// ReplicationInfo replication info in information_schema.TDBCTL_NODES's ReplicationInfo field 
+// ReplicationInfo replication info in information_schema.TDBCTL_NODES's ReplicationInfo field
 type ReplicationInfo struct {
 	MasterHost         string `json:"Master_Host"`
 	MasterPort         int    `json:"Master_Port"`
 	RelayMasterLogFile string `json:"Relay_Master_Log_File"`
 	SlaveIoRunning     string `json:"Slave_IO_Running"`
 	SlaveSqlRunning    string `json:"Slave_SQL_Running"`
-	//TODO: in the future, type should change to uint64 
+	//TODO: in the future, type should change to uint64
 	ExecMasterLogPos string `json:"Exec_Master_Log_Pos"`
 }
 
@@ -826,9 +826,9 @@ func (ins *SpiderCommonSwitch) RemoveNodeFromRoute(primaryConn *sql.DB, host str
 // GetPrimary found primary node from any connected tdbctl node's route table
 // If no primary found, return error.
 // Any blow condition could get primary success
-//  1) There is only one node: PrimaryRole, StatusOnline 
+//  1) There is only one node: PrimaryRole, StatusOnline
 //  2) No primary role found, and all alive SecondaryRole node's ReplicationMaster are the same,
-//     then thought the ReplicationMaster must be the Primary node's ServerName 
+//     then thought the ReplicationMaster must be the Primary node's ServerName
 func (ins *SpiderCommonSwitch) GetPrimary() error {
 	replicaServer := ""
 	for _, spider := range ins.SpiderNodes {

dbm-services/common/dbha/ha-module/dbmodule/dbmysql/SpiderProxyLayer_switch.go

@@ -211,11 +211,21 @@ func (ins *SpiderProxyLayerSwitch) DoSwitch() error {
 	)
 
 	//1. delete name service
-	ins.ReportLogs(constvar.InfoResult, fmt.Sprintf("try to release ip[%s#%d] from all domain entry",
-		ins.Ip, ins.Port))
-	if err := ins.DeleteNameService(ins.Entry); err != nil {
+	isSingle, err := ins.SingleAddressUnderDomain(ins.Entry)
+	if err != nil {
+		ins.ReportLogs(constvar.FailResult, fmt.Sprintf("check whether single address under domain failed:%s",
+			err.Error()))
 		return err
 	}
+	if isSingle {
+		return fmt.Errorf("only single address under this domain, skip release domain")
+	} else {
+		ins.ReportLogs(constvar.InfoResult, fmt.Sprintf("try to release ip[%s#%d] from all domain entry",
+			ins.Ip, ins.Port))
+		if err := ins.DeleteNameService(ins.Entry); err != nil {
+			return err
+		}
+	}
 
 	//2. set all spider nodes
 	if err := ins.SetSpiderNodes(); err != nil {

dbm-services/common/dbha/ha-module/dbutil/db_switch.go

@@ -184,6 +184,30 @@ func (ins *BaseSwitch) GetInfo(infoKey string) (bool, interface{}) {
 	}
 }
 
+// SingleAddressUnderDomain check whether only one address under domain
+// if only one address under dns entry, return true
+// if no dns entry found, return false
+func (ins *BaseSwitch) SingleAddressUnderDomain(entry BindEntry) (bool, error) {
+	if entry.Dns == nil {
+		return false, nil
+	}
+	conf := ins.Config
+	dnsClient := client.NewNameServiceClient(&conf.NameServices.DnsConf, conf.GetCloudId())
+	for _, dns := range entry.Dns {
+		number, err := dnsClient.GetAddressNumberByDomain(dns.DomainName)
+		if err != nil {
+			return false, err
+		}
+		ins.ReportLogs(constvar.InfoResult, fmt.Sprintf("found %d address under domain %s",
+			number, dns.DomainName))
+		if number == 1 {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
 // DeleteNameService delete broken-down ip from entry
 func (ins *BaseSwitch) DeleteNameService(entry BindEntry) error {
 	//flag refer to whether release name-service success