provider/aws: Add validation for aws_launch_configuration

builtin/providers/aws/resource_aws_launch_configuration.go

@@ -30,6 +30,15 @@ func resourceAwsLaunchConfiguration() *schema.Resource {
 				Optional: true,
 				Computed: true,
 				ForceNew: true,
+				ValidateFunc: func(v interface{}, k string) (ws []string, errors []error) {
+					// https://github.com/boto/botocore/blob/9f322b1/botocore/data/autoscaling/2011-01-01/service-2.json#L1932-L1939
+					value := v.(string)
+					if len(value) > 255 {
+						errors = append(errors, fmt.Errorf(
+							"%q cannot be longer than 255 characters", k))
+					}
+					return
+				},
 			},
 
 			"image_id": &schema.Schema{