common: don't wait SSH on first try

CHANGELOG.md

@@ -4,11 +4,10 @@ FEATURES:
 
   * builder/vmware: VMware Fusion Pro 7 is now supported. [GH-1478]
 
-IMPROVEMENTS:
-
 BUG FIXES:
 
-  * build scripts: Windows executable renamed to packer.exe. [GH-1483]
+  * core: SSH will connect slightly faster if it is ready immediately.
+  * scripts: Windows executable renamed to packer.exe. [GH-1483]
 
 ## 0.7.0 (September 8, 2014)
 

common/step_connect_ssh.go

@@ -98,13 +98,18 @@ func (s *StepConnectSSH) waitForSSH(state multistep.StateBag, cancel <-chan stru
 	handshakeAttempts := 0
 
 	var comm packer.Communicator
+	first := true
 	for {
-		select {
-		case <-cancel:
-			log.Println("SSH wait cancelled. Exiting loop.")
-			return nil, errors.New("SSH wait cancelled")
-		case <-time.After(5 * time.Second):
+		// Don't check for cancel or wait on first iteration
+		if !first {
+			select {
+			case <-cancel:
+				log.Println("SSH wait cancelled. Exiting loop.")
+				return nil, errors.New("SSH wait cancelled")
+			case <-time.After(5 * time.Second):
+			}
 		}
+		first = false
 
 		// First we request the TCP connection information
 		address, err := s.SSHAddress(state)