Add function to extend replication options (#508)

* Add function to extend replication parameters

Co-authored-by: fengwei <[email protected]>

Author: fengve

replication/binlogsyncer.go

@@ -104,6 +104,10 @@ type BinlogSyncerConfig struct {
 	// https://mariadb.com/kb/en/library/com_binlog_dump/
 	// https://mariadb.com/kb/en/library/annotate_rows_event/
 	DumpCommandFlag uint16
+
+	//Option function is used to set outside of BinlogSyncerConfig， between mysql connection and COM_REGISTER_SLAVE
+	//For MariaDB: slave_gtid_ignore_duplicates、skip_replication、slave_until_gtid
+	Option func(*client.Conn) error
 }
 
 // BinlogSyncer syncs binlog event from server.
@@ -223,6 +227,12 @@ func (b *BinlogSyncer) registerSlave() error {
 		return errors.Trace(err)
 	}
 
+	if b.cfg.Option != nil {
+		if err = b.cfg.Option(b.c); err != nil {
+			return errors.Trace(err)
+		}
+	}
+
 	if len(b.cfg.Charset) != 0 {
 		b.c.SetCharset(b.cfg.Charset)
 	}