Add support for custom dialer in canal and binlog syncer

canal/canal.go

@@ -427,6 +427,7 @@ func (c *Canal) prepareSyncer() error {
 		TimestampStringLocation: c.cfg.TimestampStringLocation,
 		TLSConfig:               c.cfg.TLSConfig,
 		Logger:                  c.cfg.Logger,
+		Dialer:                  c.cfg.Dialer,
 	}
 
 	if strings.Contains(c.cfg.Addr, "/") {
@@ -451,6 +452,14 @@ func (c *Canal) prepareSyncer() error {
 	return nil
 }
 
+func (c *Canal) connect(options ...func(*client.Conn)) (*client.Conn, error) {
+	ctx, cancel := context.WithTimeout(c.ctx, time.Second*10)
+	defer cancel()
+
+	return client.ConnectWithDialer(ctx, "", c.cfg.Addr,
+		c.cfg.User, c.cfg.Password, "", c.cfg.Dialer, options...)
+}
+
 // Execute a SQL
 func (c *Canal) Execute(cmd string, args ...interface{}) (rr *mysql.Result, err error) {
 	c.connLock.Lock()
@@ -461,27 +470,28 @@ func (c *Canal) Execute(cmd string, args ...interface{}) (rr *mysql.Result, err
 			conn.SetTLSConfig(c.cfg.TLSConfig)
 		})
 	}
+
 	retryNum := 3
 	for i := 0; i < retryNum; i++ {
 		if c.conn == nil {
-			c.conn, err = client.Connect(c.cfg.Addr, c.cfg.User, c.cfg.Password, "", argF...)
+			c.conn, err = c.connect(argF...)
 			if err != nil {
 				return nil, errors.Trace(err)
 			}
 		}
 
 		rr, err = c.conn.Execute(cmd, args...)
-		if err != nil && !mysql.ErrorEqual(err, mysql.ErrBadConn) {
-			return
-		} else if mysql.ErrorEqual(err, mysql.ErrBadConn) {
-			c.conn.Close()
-			c.conn = nil
-			continue
-		} else {
-			return
+		if err != nil {
+			if mysql.ErrorEqual(err, mysql.ErrBadConn) {
+				c.conn.Close()
+				c.conn = nil
+				continue
+			}
+			return nil, err
 		}
+		break
 	}
-	return
+	return rr, err
 }
 
 func (c *Canal) SyncedPosition() mysql.Position {

canal/config.go

@@ -4,10 +4,12 @@ import (
 	"crypto/tls"
 	"io/ioutil"
 	"math/rand"
+	"net"
 	"os"
 	"time"
 
 	"github.com/BurntSushi/toml"
+	"github.com/go-mysql-org/go-mysql/client"
 	"github.com/go-mysql-org/go-mysql/mysql"
 	"github.com/pingcap/errors"
 	"github.com/siddontang/go-log/log"
@@ -91,6 +93,9 @@ type Config struct {
 
 	//Set Logger
 	Logger *log.Logger
+
+	//Set Dialer
+	Dialer client.Dialer
 }
 
 func NewConfigWithFile(name string) (*Config, error) {
@@ -132,5 +137,8 @@ func NewDefaultConfig() *Config {
 	streamHandler, _ := log.NewStreamHandler(os.Stdout)
 	c.Logger = log.NewDefault(streamHandler)
 
+	dialer := &net.Dialer{}
+	c.Dialer = dialer.DialContext
+
 	return c
 }

client/conn.go

@@ -61,14 +61,12 @@ func getNetProto(addr string) string {
 // Connect to a MySQL server, addr can be ip:port, or a unix socket domain like /var/sock.
 // Accepts a series of configuration functions as a variadic argument.
 func Connect(addr string, user string, password string, dbName string, options ...func(*Conn)) (*Conn, error) {
-	proto := getNetProto(addr)
-
 	ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
 	defer cancel()
 
 	dialer := &net.Dialer{}
 
-	return ConnectWithDialer(ctx, proto, addr, user, password, dbName, dialer.DialContext, options...)
+	return ConnectWithDialer(ctx, "", addr, user, password, dbName, dialer.DialContext, options...)
 }
 
 // Dialer connects to the address on the named network using the provided context.
@@ -78,6 +76,10 @@ type Dialer func(ctx context.Context, network, address string) (net.Conn, error)
 func ConnectWithDialer(ctx context.Context, network string, addr string, user string, password string, dbName string, dialer Dialer, options ...func(*Conn)) (*Conn, error) {
 	c := new(Conn)
 
+	if network == "" {
+		network = getNetProto(addr)
+	}
+
 	var err error
 	conn, err := dialer(ctx, network, addr)
 	if err != nil {

replication/binlogsyncer.go

@@ -112,6 +112,9 @@ type BinlogSyncerConfig struct {
 
 	// Set Logger
 	Logger *log.Logger
+
+	// Set Dialer
+	Dialer client.Dialer
 }
 
 // BinlogSyncer syncs binlog event from server.
@@ -149,6 +152,10 @@ func NewBinlogSyncer(cfg BinlogSyncerConfig) *BinlogSyncer {
 	if cfg.ServerID == 0 {
 		cfg.Logger.Fatal("can't use 0 as the server ID")
 	}
+	if cfg.Dialer == nil {
+		dialer := &net.Dialer{}
+		cfg.Dialer = dialer.DialContext
+	}
 
 	// Clear the Password to avoid outputing it in log.
 	pass := cfg.Password
@@ -864,9 +871,13 @@ func (b *BinlogSyncer) newConnection() (*client.Conn, error) {
 		addr = b.cfg.Host
 	}
 
-	return client.Connect(addr, b.cfg.User, b.cfg.Password, "", func(c *client.Conn) {
-		c.SetTLSConfig(b.cfg.TLSConfig)
-	})
+	ctx, cancel := context.WithTimeout(b.ctx, time.Second*10)
+	defer cancel()
+
+	return client.ConnectWithDialer(ctx, "", addr, b.cfg.User, b.cfg.Password,
+		"", b.cfg.Dialer, func(c *client.Conn) {
+			c.SetTLSConfig(b.cfg.TLSConfig)
+		})
 }
 
 func (b *BinlogSyncer) killConnection(conn *client.Conn, id uint32) {