kite: add configurable timeout support

Author: rjeczalik

config/config.go

@@ -71,6 +71,18 @@ type Config struct {
 	// Required.
 	XHR *http.Client
 
+	// Timeout specified max time waiting for the following operations to complete:
+	//
+	//   - polling on an XHR connection
+	//   - default timeout for certain kite requests (Kontrol API)
+	//   - HTTP heartbeats and register method
+	//
+	// NOTE: Ensure the Timeout is higher than SockJS.HeartbeatDelay, otherwise
+	// XHR connections may get randomly closed.
+	//
+	// TODO(rjeczalik): Make kite heartbeats configurable as well.
+	Timeout time.Duration
+
 	// Client is a HTTP client used for issuing HTTP register request and
 	// HTTP heartbeats.
 	Client *http.Client
@@ -101,15 +113,12 @@ var DefaultConfig = &Config{
 	IP:          "0.0.0.0",
 	Port:        0,
 	Transport:   Auto,
+	Timeout:     15 * time.Second,
 	XHR: &http.Client{
-		// TODO(rjeczalik): make XHR handler timeout if polling on body
-		// is idle > timeout. Timing out after 10s is a bad idea when
-		// the connection is active.
-		// Timeout: 10 * time.Second,
 		Jar: CookieJar,
 	},
 	Client: &http.Client{
-		Timeout: 20 * time.Second,
+		Timeout: 15 * time.Second,
 		Jar:     CookieJar,
 	},
 	Websocket: &websocket.Dialer{
@@ -121,7 +130,7 @@ var DefaultConfig = &Config{
 		JSessionID:      sockjs.DefaultOptions.JSessionID,
 		SockJSURL:       sockjs.DefaultOptions.SockJSURL,
 		HeartbeatDelay:  10 * time.Second, // better fit for AWS ELB; empirically picked
-		DisconnectDelay: 10 * time.Second, // >= XHR poll interval
+		DisconnectDelay: 10 * time.Second, // >= Timeout
 		ResponseLimit:   sockjs.DefaultOptions.ResponseLimit,
 	},
 }
@@ -210,7 +219,8 @@ func (c *Config) ReadEnvironmentVariables() error {
 	}
 
 	if timeout, err := time.ParseDuration(os.Getenv("KITE_TIMEOUT")); err == nil {
-		c.XHR.Timeout = timeout
+		c.Timeout = timeout
+		c.Client.Timeout = timeout
 	}
 
 	if timeout, err := time.ParseDuration(os.Getenv("KITE_HANDSHAKE_TIMEOUT")); err == nil {

kontrolclient.go

@@ -17,10 +17,6 @@ import (
 const (
 	kontrolRetryDuration = 10 * time.Second
 	proxyRetryDuration   = 10 * time.Second
-
-	// kontrolConnectTimeout is the timeout for connecting to Kontrol in
-	// TellKontrol-like methods.
-	kontrolConnectTimeout = 10 * time.Second
 )
 
 // Returned from GetKites when query matches no kites.
@@ -146,7 +142,7 @@ func (k *Kite) GetKites(query *protocol.KontrolQuery) ([]*Client, error) {
 func (k *Kite) getKites(args protocol.GetKitesArgs) ([]*Client, error) {
 	<-k.kontrol.readyConnected
 
-	response, err := k.kontrol.TellWithTimeout("getKites", 4*time.Second, args)
+	response, err := k.kontrol.TellWithTimeout("getKites", k.Config.Timeout, args)
 	if err != nil {
 		return nil, err
 	}
@@ -195,7 +191,7 @@ func (k *Kite) GetToken(kite *protocol.Kite) (string, error) {
 
 	<-k.kontrol.readyConnected
 
-	result, err := k.kontrol.TellWithTimeout("getToken", 4*time.Second, kite)
+	result, err := k.kontrol.TellWithTimeout("getToken", k.Config.Timeout, kite)
 	if err != nil {
 		return "", err
 	}
@@ -225,7 +221,7 @@ func (k *Kite) GetTokenForce(kite *protocol.Kite) (string, error) {
 		Force:        true,
 	}
 
-	result, err := k.kontrol.TellWithTimeout("getToken", 4*time.Second, args)
+	result, err := k.kontrol.TellWithTimeout("getToken", k.Config.Timeout, args)
 	if err != nil {
 		return "", err
 	}
@@ -250,7 +246,7 @@ func (k *Kite) GetKey() (string, error) {
 
 	<-k.kontrol.readyConnected
 
-	result, err := k.kontrol.TellWithTimeout("getKey", 4*time.Second)
+	result, err := k.kontrol.TellWithTimeout("getKey", k.Config.Timeout)
 	if err != nil {
 		return "", err
 	}
@@ -358,7 +354,7 @@ func (k *Kite) Register(kiteURL *url.URL) (*registerResult, error) {
 
 	k.Log.Info("Registering to kontrol with URL: %s", kiteURL.String())
 
-	response, err := k.kontrol.TellWithTimeout("register", 4*time.Second, args)
+	response, err := k.kontrol.TellWithTimeout("register", k.Config.Timeout, args)
 	if err != nil {
 		return nil, err
 	}
@@ -477,7 +473,7 @@ func (k *Kite) registerToProxyKite(c *Client, kiteURL *url.URL) (*url.URL, error
 
 	// this could be tunnelproxy or reverseproxy. Tunnelproxy doesn't need an
 	// URL however Reverseproxy needs one.
-	result, err := c.TellWithTimeout("register", 4*time.Second, kiteURL.String())
+	result, err := c.TellWithTimeout("register", k.Config.Timeout, kiteURL.String())
 	if err != nil {
 		k.Log.Error("Proxy register error: %s", err.Error())
 		return nil, err
@@ -508,12 +504,12 @@ func (k *Kite) TellKontrolWithTimeout(method string, timeout time.Duration, args
 
 	// Wait for readyConnect, or timeout
 	select {
-	case <-time.After(kontrolConnectTimeout):
+	case <-time.After(k.Config.Timeout):
 		return nil, &Error{
 			Type: "timeout",
 			Message: fmt.Sprintf(
 				"Timed out registering to kontrol for %s method after %s",
-				method, kontrolConnectTimeout,
+				method, k.Config.Timeout,
 			),
 		}
 	case <-k.kontrol.readyConnected: