*: make dial timeout configurable

Dial timeout is set shorter because
1. etcd is supposed to work in good environment, and the new value is long
enough
2. shorter dial timeout makes dial fail faster, which is good for
performance

Conflicts:
	etcdmain/etcd.go

etcdmain/etcd.go

@@ -116,7 +116,7 @@ func startEtcd(cfg *config) (<-chan struct{}, error) {
 		return nil, fmt.Errorf("error setting up initial cluster: %v", err)
 	}
 
-	pt, err := transport.NewTimeoutTransport(cfg.peerTLSInfo, rafthttp.ConnReadTimeout, rafthttp.ConnWriteTimeout)
+	pt, err := transport.NewTimeoutTransport(cfg.peerTLSInfo, rafthttp.DialTimeout, rafthttp.ConnReadTimeout, rafthttp.ConnWriteTimeout)
 	if err != nil {
 		return nil, err
 	}

integration/cluster_test.go

@@ -663,7 +663,7 @@ func mustNewHTTPClient(t *testing.T, eps []string) client.HTTPClient {
 }
 
 func mustNewTransport(t *testing.T) *http.Transport {
-	tr, err := transport.NewTimeoutTransport(transport.TLSInfo{}, rafthttp.ConnReadTimeout, rafthttp.ConnWriteTimeout)
+	tr, err := transport.NewTimeoutTransport(transport.TLSInfo{}, rafthttp.DialTimeout, rafthttp.ConnReadTimeout, rafthttp.ConnWriteTimeout)
 	if err != nil {
 		t.Fatal(err)
 	}

pkg/transport/timeout_transport.go

@@ -23,7 +23,7 @@ import (
 // NewTimeoutTransport returns a transport created using the given TLS info.
 // If read/write on the created connection blocks longer than its time limit,
 // it will return timeout error.
-func NewTimeoutTransport(info TLSInfo, rdtimeoutd, wtimeoutd time.Duration) (*http.Transport, error) {
+func NewTimeoutTransport(info TLSInfo, dialtimeoutd, rdtimeoutd, wtimeoutd time.Duration) (*http.Transport, error) {
 	tr, err := NewTransport(info)
 	if err != nil {
 		return nil, err
@@ -33,7 +33,7 @@ func NewTimeoutTransport(info TLSInfo, rdtimeoutd, wtimeoutd time.Duration) (*ht
 	tr.MaxIdleConnsPerHost = -1
 	tr.Dial = (&rwTimeoutDialer{
 		Dialer: net.Dialer{
-			Timeout:   30 * time.Second,
+			Timeout:   dialtimeoutd,
 			KeepAlive: 30 * time.Second,
 		},
 		rdtimeoutd: rdtimeoutd,

pkg/transport/timeout_transport_test.go

@@ -26,7 +26,7 @@ import (
 // TestNewTimeoutTransport tests that NewTimeoutTransport returns a transport
 // that can dial out timeout connections.
 func TestNewTimeoutTransport(t *testing.T) {
-	tr, err := NewTimeoutTransport(TLSInfo{}, time.Hour, time.Hour)
+	tr, err := NewTimeoutTransport(TLSInfo{}, time.Hour, time.Hour, time.Hour)
 	if err != nil {
 		t.Fatalf("unexpected NewTimeoutTransport error: %v", err)
 	}

rafthttp/peer.go

@@ -40,6 +40,7 @@ const (
 	appRespBatchMs = 50
 	propBatchMs    = 10
 
+	DialTimeout      = time.Second
 	ConnReadTimeout  = 5 * time.Second
 	ConnWriteTimeout = 5 * time.Second
 )