From cc081335f9f9c713ae2f26dee8c383313f6c7a74 Mon Sep 17 00:00:00 2001
From: David Rocamora <dave@n22t.com>
Date: Tue, 18 Feb 2014 12:08:29 -0500
Subject: [PATCH] Test if on EC2 before trying IAM role auth

---
 common.go | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/common.go b/common.go
index 2233210..7723478 100644
--- a/common.go
+++ b/common.go
@@ -11,6 +11,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
+	"net"
 	"net/http"
 	"net/url"
 	"os"
@@ -52,7 +53,7 @@ func checkKeys() {
 		}
 	}
 	// if accesskey and the secretkey are blank, get the key from the role
-	if Keys.AccessKeyID == "" {
+	if Keys.AccessKeyID == "" && onEC2() {
 
 		Keys = getIAMRoleCredentials()
 	}
@@ -63,6 +64,18 @@ func checkKeys() {
 	}
 }
 
+func onEC2() bool {
+
+	c, err := net.DialTimeout("tcp", "169.254.169.254:80", time.Second)
+
+	if err != nil {
+		return false
+	} else {
+		c.Close()
+		return true
+	}
+}
+
 func getIAMRoleList() []string {
 	// Get a list of the roles that are available to this instance
 	url := "http://169.254.169.254/latest/meta-data/iam/security-credentials/"