Specify a custom dial function per config

Author: aaronjheng

connector.go

@@ -77,20 +77,30 @@ func (c *connector) Connect(ctx context.Context) (driver.Conn, error){
 mc.parseTime=mc.cfg.ParseTime
 
 // Connect to Server
-dialsLock.RLock()
-dial, ok:=dials[mc.cfg.Net]
-dialsLock.RUnlock()
-ifok{
+ifc.cfg.DialFunc!=nil{
 dctx:=ctx
 ifmc.cfg.Timeout>0{
 varcancel context.CancelFunc
 dctx, cancel=context.WithTimeout(ctx, c.cfg.Timeout)
 defercancel()
  }
-mc.netConn, err=dial(dctx, mc.cfg.Addr)
+mc.netConn, err=c.cfg.DialFunc(dctx, mc.cfg.Net, mc.cfg.Addr)
  } else{
-nd:= net.Dialer{Timeout: mc.cfg.Timeout}
-mc.netConn, err=nd.DialContext(ctx, mc.cfg.Net, mc.cfg.Addr)
+dialsLock.RLock()
+dial, ok:=dials[mc.cfg.Net]
+dialsLock.RUnlock()
+ifok{
+dctx:=ctx
+ifmc.cfg.Timeout>0{
+varcancel context.CancelFunc
+dctx, cancel=context.WithTimeout(ctx, c.cfg.Timeout)
+defercancel()
+ }
+mc.netConn, err=dial(dctx, mc.cfg.Addr)
+ } else{
+nd:= net.Dialer{Timeout: mc.cfg.Timeout}
+mc.netConn, err=nd.DialContext(ctx, mc.cfg.Net, mc.cfg.Addr)
+ }
  }
 
 iferr!=nil{

dsn.go

@@ -10,6 +10,7 @@ package mysql
 
 import (
 "bytes"
+"context"
 "crypto/rsa"
 "crypto/tls"
 "errors"
@@ -34,24 +35,25 @@ var (
 // If a new Config is created instead of being parsed from a DSN string,
 // the NewConfig function should be used, which sets default values.
 typeConfigstruct{
-Userstring// Username
-Passwdstring// Password (requires User)
-Netstring// Network (e.g. "tcp", "tcp6", "unix". default: "tcp")
-Addrstring// Address (default: "127.0.0.1:3306" for "tcp" and "/tmp/mysql.sock" for "unix")
-DBNamestring// Database name
-Paramsmap[string]string// Connection parameters
-ConnectionAttributesstring// Connection Attributes, comma-delimited string of user-defined "key:value" pairs
-Collationstring// Connection collation
-Loc*time.Location// Location for time.Time values
-MaxAllowedPacketint// Max packet size allowed
-ServerPubKeystring// Server public key name
-pubKey*rsa.PublicKey// Server public key
-TLSConfigstring// TLS configuration name
-TLS*tls.Config// TLS configuration, its priority is higher than TLSConfig
-Timeout time.Duration// Dial timeout
-ReadTimeout time.Duration// I/O read timeout
-WriteTimeout time.Duration// I/O write timeout
-LoggerLogger// Logger
+Userstring// Username
+Passwdstring// Password (requires User)
+Netstring// Network (e.g. "tcp", "tcp6", "unix". default: "tcp")
+Addrstring// Address (default: "127.0.0.1:3306" for "tcp" and "/tmp/mysql.sock" for "unix")
+DBNamestring// Database name
+Paramsmap[string]string// Connection parameters
+ConnectionAttributesstring// Connection Attributes, comma-delimited string of user-defined "key:value" pairs
+Collationstring// Connection collation
+Loc*time.Location// Location for time.Time values
+MaxAllowedPacketint// Max packet size allowed
+ServerPubKeystring// Server public key name
+pubKey*rsa.PublicKey// Server public key
+TLSConfigstring// TLS configuration name
+TLS*tls.Config// TLS configuration, its priority is higher than TLSConfig
+Timeout time.Duration// Dial timeout
+ReadTimeout time.Duration// I/O read timeout
+WriteTimeout time.Duration// I/O write timeout
+LoggerLogger// Logger
+DialFuncfunc(ctx context.Context, network, addrstring) (net.Conn, error) // Specifies the dial function for creating connections
 
 AllowAllFilesbool// Allow all files to be used with LOAD DATA LOCAL INFILE
 AllowCleartextPasswordsbool// Allows the cleartext client side plugin