MCE-18894 Load Binlog Position from Redis

This was already implemented before the go-mysql MySQL 8 upgrade but we missed refactoring this part after we merged upstream code. Co-authored-by: Mario Poveda <mario.poveda@instructure.com>

Author: forain

canal/canal.go

@@ -93,6 +93,13 @@ func NewCanal(cfg *Config) (*Canal, error) {
 c.delay = new(uint32)
 
 var err error
+if err = c.master.infoLoader.Load(c.master.Setter); err != nil {
+return nil, errors.Trace(err)
+} else if len(c.master.Addr) != 0 && c.master.Addr != c.cfg.Addr {
+c.cfg.Logger.Infof("MySQL addr %s in old master.info, but new %s, reset", c.master.Addr, c.cfg.Addr)
+// may use another MySQL, reset
+c.master = &masterInfo{infoLoader: c.master.infoLoader} // keep the configured info loader
+}
 
 if err = c.prepareDumper(); err != nil {
 return nil, errors.Trace(err)