From c8508ade17696ff07199c9c3c0aa503fbd20d230 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Sat, 3 Aug 2013 16:37:34 -0700
Subject: [PATCH] builder/amazon/common: be more gentle on AWS API while
 getting SSHAddr

---
 builder/amazon/common/ssh.go | 43 ++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/builder/amazon/common/ssh.go b/builder/amazon/common/ssh.go
index 808a868f6..a5ddf8fae 100644
--- a/builder/amazon/common/ssh.go
+++ b/builder/amazon/common/ssh.go
@@ -12,27 +12,32 @@ import (
 // for determining the SSH address based on the instance DNS name.
 func SSHAddress(e *ec2.EC2, port int) func(map[string]interface{}) (string, error) {
 	return func(state map[string]interface{}) (string, error) {
-		var host string
-		i := state["instance"].(*ec2.Instance)
-		r, err := e.Instances([]string{i.InstanceId}, ec2.NewFilter())
-		if err != nil {
-			return "", err
+		for j := 0; j < 2; j++ {
+			var host string
+			i := state["instance"].(*ec2.Instance)
+			if i.DNSName != "" {
+				host = i.DNSName
+			} else if i.VpcId == "" {
+				host = i.PrivateIpAddress
+			}
+
+			if host != "" {
+				return fmt.Sprintf("%s:%d", host, port), nil
+			}
+
+			r, err := e.Instances([]string{i.InstanceId}, ec2.NewFilter())
+			if err != nil {
+				return "", err
+			}
+
+			if len(r.Reservations) == 0 || len(r.Reservations[0].Instances) == 0 {
+				return "", fmt.Errorf("instance not found: %s", i.InstanceId)
+			}
+
+			state["instance"] = &r.Reservations[0].Instances[0]
 		}
 
-		if len(r.Reservations) == 0 || len(r.Reservations[0].Instances) == 0 {
-			return "", fmt.Errorf("instance not found: %s", i.InstanceId)
-		}
-
-		i = &r.Reservations[0].Instances[0]
-		if i.DNSName != "" {
-			host = i.DNSName
-		} else if i.VpcId == "" {
-			host = i.PrivateIpAddress
-		} else {
-			return "", errors.New("couldn't determine IP address for instance")
-		}
-
-		return fmt.Sprintf("%s:%d", host, port), nil
+		return "", errors.New("couldn't determine IP address for instance")
 	}
 }