revert hostname md5

Author: jianhaiqing

mysql/mysql_test.go

@@ -1,8 +1,6 @@
 package mysql
 
 import (
-	"crypto/md5"
-	"encoding/hex"
 	"strings"
 	"testing"
 
@@ -120,30 +118,6 @@ func (t *mysqlTestSuite) TestMysqlGTIDContain(c *check.C) {
 	c.Assert(g1.Contain(g2), check.Equals, false)
 }
 
-func (t *mysqlTestSuite) TestHostnameMd5sum(c *check.C) {
-	// if os.Hostname() lengther than 60, use md5sum instead
-	tbl := []struct {
-		hashStr string
-		sum     int
-	}{
-		{`app-f084ccc2f5dd37da027539dc9d2cb1581c2237d4-1-7ff988bd9f-t2cx7`, 32},
-		{`jianhaiqingxxx`, 14},
-		{`dfmpzqy7wjvwotpadgkiinkl5bjtdkuu.aliyundunwaf.com.dfmpzqy7wjvwotpadgkiinkl5bjtdkuu.aliyundunwaf.com.dfmpzqy7wjvwotpadgkiinkl5bjtdkuu.aliyundunwaf.com.`, 32},
-	}
-	var get int
-	for _, t := range tbl {
-		if len(t.hashStr) > 60 {
-			hasher := md5.New()
-			hasher.Write([]byte(t.hashStr))
-			get = len(hex.EncodeToString(hasher.Sum(nil)))
-		} else {
-			get = len(t.hashStr)
-		}
-		c.Assert(get == t.sum, check.IsTrue)
-	}
-
-}
-
 func (t *mysqlTestSuite) TestMysqlParseBinaryInt8(c *check.C) {
 	i8 := ParseBinaryInt8([]byte{128})
 	c.Assert(i8, check.Equals, int8(-128))

replication/binlogsyncer.go

@@ -2,10 +2,8 @@ package replication
 
 import (
 	"context"
-	"crypto/md5"
 	"crypto/tls"
 	"encoding/binary"
-	"encoding/hex"
 	"fmt"
 	"net"
 	"os"
@@ -498,12 +496,6 @@ func (b *BinlogSyncer) writeBinlogDumpMariadbGTIDCommand(gset GTIDSet) error {
 func (b *BinlogSyncer) localHostname() string {
 	if len(b.cfg.Localhost) == 0 {
 		h, _ := os.Hostname()
-		// if os.Hostname() lengther than 60, use md5sum instead
-		if len(h) > 60 {
-			hasher := md5.New()
-			hasher.Write([]byte(h))
-			return hex.EncodeToString(hasher.Sum(nil))
-		}
 		return h
 	}
 	return b.cfg.Localhost