provider/aws: fix case in ELB listener protocols

fixes #2242

builtin/providers/aws/resource_aws_elb.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"log"
+	"strings"
 
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/awserr"
@@ -541,9 +542,11 @@ func resourceAwsElbListenerHash(v interface{}) int {
 	var buf bytes.Buffer
 	m := v.(map[string]interface{})
 	buf.WriteString(fmt.Sprintf("%d-", m["instance_port"].(int)))
-	buf.WriteString(fmt.Sprintf("%s-", m["instance_protocol"].(string)))
+	buf.WriteString(fmt.Sprintf("%s-",
+		strings.ToLower(m["instance_protocol"].(string))))
 	buf.WriteString(fmt.Sprintf("%d-", m["lb_port"].(int)))
-	buf.WriteString(fmt.Sprintf("%s-", m["lb_protocol"].(string)))
+	buf.WriteString(fmt.Sprintf("%s-",
+		strings.ToLower(m["lb_protocol"].(string))))
 
 	if v, ok := m["ssl_certificate_id"]; ok {
 		buf.WriteString(fmt.Sprintf("%s-", v.(string)))

builtin/providers/aws/resource_aws_elb_test.go

@@ -362,6 +362,39 @@ func TestAccAWSELB_SecurityGroups(t *testing.T) {
 	})
 }
 
+// Unit test for listeners hash
+func TestResourceAwsElbListenerHash(t *testing.T) {
+	cases := map[string]struct {
+		Left  map[string]interface{}
+		Right map[string]interface{}
+		Match bool
+	}{
+		"protocols are case insensitive": {
+			map[string]interface{}{
+				"instance_port":     80,
+				"instance_protocol": "TCP",
+				"lb_port":           80,
+				"lb_protocol":       "TCP",
+			},
+			map[string]interface{}{
+				"instance_port":     80,
+				"instance_protocol": "Tcp",
+				"lb_port":           80,
+				"lb_protocol":       "tcP",
+			},
+			true,
+		},
+	}
+
+	for tn, tc := range cases {
+		leftHash := resourceAwsElbListenerHash(tc.Left)
+		rightHash := resourceAwsElbListenerHash(tc.Right)
+		if (leftHash == rightHash) != tc.Match {
+			t.Fatalf("%s: expected match: %t, but did not get it", tn, tc.Match)
+		}
+	}
+}
+
 func testAccCheckAWSELBDestroy(s *terraform.State) error {
 	conn := testAccProvider.Meta().(*AWSClient).elbconn
 
@@ -513,7 +546,8 @@ resource "aws_elb" "bar" {
     instance_port = 8000
     instance_protocol = "http"
     lb_port = 80
-    lb_protocol = "http"
+    // Protocol should be case insensitive
+    lb_protocol = "HttP"
   }
 
 	tags {