From 0fdf91661d121d56314ad1e899b17729b2d0ee05 Mon Sep 17 00:00:00 2001
From: Hector Rivas Gandara <keymon@gmail.com>
Date: Fri, 8 Apr 2016 19:55:50 +0100
Subject: [PATCH] provider/aws: normalize json policy for sns topic policy
 attribute (#6089)

* provider/aws: test empty plan with sns_topic policy with random order

If we setup a sns_topic policy with a policy with a different order
to the one set by the AWS API, terraform plan will be not empty between
runs.

* provider/aws: normalize json policy for sns topic

For the policy attribute of the resource aws_sns_topic,  AWS returns the policy
in JSON format with the fields in a different order.
If we store and compare the values without normalizing, terraform
will unnecesary trigger and update of the resource.

To avoid that, we must add a normalization function in the StateFunc of
the policy attribute and also when we read the attribute from AWS.
---
 builtin/providers/aws/resource_aws_sns_topic.go     | 13 ++++++++++---
 .../providers/aws/resource_aws_sns_topic_test.go    |  6 +++---
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/builtin/providers/aws/resource_aws_sns_topic.go b/builtin/providers/aws/resource_aws_sns_topic.go
index 6a8e62fa7e33..4174e8732c94 100644
--- a/builtin/providers/aws/resource_aws_sns_topic.go
+++ b/builtin/providers/aws/resource_aws_sns_topic.go
@@ -56,7 +56,9 @@ func resourceAwsSnsTopic() *schema.Resource {
 						log.Printf("[WARN] Error compacting JSON for Policy in SNS Topic")
 						return ""
 					}
-					return buffer.String()
+					value := normalizeJson(buffer.String())
+					log.Printf("[DEBUG] topic policy before save: %s", value)
+					return value
 				},
 			},
 			"delivery_policy": &schema.Schema{
@@ -183,9 +185,14 @@ func resourceAwsSnsTopicRead(d *schema.ResourceData, meta interface{}) error {
 				// Some of the fetched attributes are stateful properties such as
 				// the number of subscriptions, the owner, etc. skip those
 				if resource.Schema[iKey] != nil {
-					value := *attrmap[oKey]
+					var value string
+					if iKey == "policy" {
+						value = normalizeJson(*attrmap[oKey])
+					} else {
+						value = *attrmap[oKey]
+					}
 					log.Printf("[DEBUG] Reading %s => %s -> %s", iKey, oKey, value)
-					d.Set(iKey, *attrmap[oKey])
+					d.Set(iKey, value)
 				}
 			}
 		}
diff --git a/builtin/providers/aws/resource_aws_sns_topic_test.go b/builtin/providers/aws/resource_aws_sns_topic_test.go
index 76510c76ee6c..2852c36fb2c3 100644
--- a/builtin/providers/aws/resource_aws_sns_topic_test.go
+++ b/builtin/providers/aws/resource_aws_sns_topic_test.go
@@ -128,8 +128,6 @@ resource "aws_sns_topic" "test_topic" {
   name = "example"
   policy = <<EOF
 {
-  "Version": "2012-10-17",
-  "Id": "Policy1445931846145",
   "Statement": [
     {
       "Sid": "Stmt1445931846145",
@@ -140,7 +138,9 @@ resource "aws_sns_topic" "test_topic" {
       "Action": "sns:Publish",
       "Resource": "arn:aws:sns:us-west-2::example"
     }
-  ]
+  ],
+  "Version": "2012-10-17",
+  "Id": "Policy1445931846145"
 }
 EOF
 }