From efa26ed2a7eac658ad92793d9d2361fff1f2d007 Mon Sep 17 00:00:00 2001
From: Clint Shryock <clint@ctshryock.com>
Date: Thu, 1 Oct 2015 17:00:30 -0500
Subject: [PATCH] provider/aws: Fix issue with disabling source dest check on
 first run

---
 .../providers/aws/resource_aws_instance.go    | 32 ++++++++++---------
 .../aws/resource_aws_instance_test.go         |  3 ++
 2 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/builtin/providers/aws/resource_aws_instance.go b/builtin/providers/aws/resource_aws_instance.go
index 093b6ae86..faac6e0a5 100644
--- a/builtin/providers/aws/resource_aws_instance.go
+++ b/builtin/providers/aws/resource_aws_instance.go
@@ -414,11 +414,6 @@ func resourceAwsInstanceCreate(d *schema.ResourceData, meta interface{}) error {
 		})
 	}
 
-	// Set our attributes
-	if err := resourceAwsInstanceRead(d, meta); err != nil {
-		return err
-	}
-
 	// Update if we need to
 	return resourceAwsInstanceUpdate(d, meta)
 }
@@ -548,16 +543,23 @@ func resourceAwsInstanceUpdate(d *schema.ResourceData, meta interface{}) error {
 	}
 
 	// SourceDestCheck can only be set on VPC instances
-	if d.Get("subnet_id").(string) != "" {
-		log.Printf("[INFO] Modifying instance %s", d.Id())
-		_, err := conn.ModifyInstanceAttribute(&ec2.ModifyInstanceAttributeInput{
-			InstanceId: aws.String(d.Id()),
-			SourceDestCheck: &ec2.AttributeBooleanValue{
-				Value: aws.Bool(d.Get("source_dest_check").(bool)),
-			},
-		})
-		if err != nil {
-			return err
+	// AWS will return an error of InvalidParameterCombination if we attempt
+	// to modify the source_dest_check of an instance in EC2 Classic
+	log.Printf("[INFO] Modifying instance %s", d.Id())
+	_, err := conn.ModifyInstanceAttribute(&ec2.ModifyInstanceAttributeInput{
+		InstanceId: aws.String(d.Id()),
+		SourceDestCheck: &ec2.AttributeBooleanValue{
+			Value: aws.Bool(d.Get("source_dest_check").(bool)),
+		},
+	})
+	if err != nil {
+		if ec2err, ok := err.(awserr.Error); ok {
+			// Toloerate InvalidParameterCombination error in Classic, otherwise
+			// return the error
+			if "InvalidParameterCombination" != ec2err.Code() {
+				return err
+			}
+			log.Printf("[WARN] Attempted to modify SourceDestCheck on non VPC instance: %s", ec2err.Message())
 		}
 	}
 
diff --git a/builtin/providers/aws/resource_aws_instance_test.go b/builtin/providers/aws/resource_aws_instance_test.go
index 258320d54..3224f9b5e 100644
--- a/builtin/providers/aws/resource_aws_instance_test.go
+++ b/builtin/providers/aws/resource_aws_instance_test.go
@@ -190,6 +190,9 @@ func TestAccAWSInstance_sourceDestCheck(t *testing.T) {
 
 	testCheck := func(enabled bool) resource.TestCheckFunc {
 		return func(*terraform.State) error {
+			if v.SourceDestCheck == nil {
+				return fmt.Errorf("bad source_dest_check: got nil")
+			}
 			if *v.SourceDestCheck != enabled {
 				return fmt.Errorf("bad source_dest_check: %#v", *v.SourceDestCheck)
 			}