From 6f2fb0db384cd87933e6abb61005168ae8f85f2b Mon Sep 17 00:00:00 2001
From: Radek Simko <radek.simko@timeinc.com>
Date: Thu, 25 Jun 2015 11:00:15 +0100
Subject: [PATCH] provider/aws: Add validation for aws_elb.name

---
 builtin/providers/aws/resource_aws_elb.go | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/builtin/providers/aws/resource_aws_elb.go b/builtin/providers/aws/resource_aws_elb.go
index ebc45c941183..08fde29a263f 100644
--- a/builtin/providers/aws/resource_aws_elb.go
+++ b/builtin/providers/aws/resource_aws_elb.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"log"
+	"regexp"
 	"strings"
 
 	"github.com/aws/aws-sdk-go/aws"
@@ -25,6 +26,26 @@ func resourceAwsElb() *schema.Resource {
 				Type:     schema.TypeString,
 				Required: true,
 				ForceNew: true,
+				ValidateFunc: func(v interface{}, k string) (ws []string, errors []error) {
+					value := v.(string)
+					if !regexp.MustCompile(`^[0-9a-z-]$`).MatchString(value) {
+						errors = append(errors, fmt.Errorf(
+							"only lowercase alphanumeric characters and hyphens allowed in %q", k))
+					}
+					if len(value) > 32 {
+						errors = append(errors, fmt.Errorf(
+							"%q cannot be longer than 32 characters", k))
+					}
+					if regexp.MustCompile(`^-`).MatchString(value) {
+						errors = append(errors, fmt.Errorf(
+							"%q cannot begin with a hyphen", k))
+					}
+					if regexp.MustCompile(`-$`).MatchString(value) {
+						errors = append(errors, fmt.Errorf(
+							"%q cannot end with a hyphen", k))
+					}
+					return
+				},
 			},
 
 			"internal": &schema.Schema{