From fdc21aad25b947a443126ed8d0d39c1e0ff263a9 Mon Sep 17 00:00:00 2001
From: Radek Simko <radek.simko@timeinc.com>
Date: Fri, 19 Feb 2016 12:13:26 +0000
Subject: [PATCH] provider/aws: Simplify update logic for Lambda function

---
 .../aws/resource_aws_lambda_function.go       | 74 ++++---------------
 1 file changed, 15 insertions(+), 59 deletions(-)

diff --git a/builtin/providers/aws/resource_aws_lambda_function.go b/builtin/providers/aws/resource_aws_lambda_function.go
index 178b0d88ff..692d1b0f3e 100644
--- a/builtin/providers/aws/resource_aws_lambda_function.go
+++ b/builtin/providers/aws/resource_aws_lambda_function.go
@@ -1,8 +1,6 @@
 package aws
 
 import (
-	"crypto/sha256"
-	"encoding/base64"
 	"fmt"
 	"io/ioutil"
 	"log"
@@ -103,11 +101,6 @@ func resourceAwsLambdaFunction() *schema.Resource {
 					},
 				},
 			},
-			"update_code": &schema.Schema{
-				Type:     schema.TypeBool,
-				Optional: true,
-				Default:  false,
-			},
 			"arn": &schema.Schema{
 				Type:     schema.TypeString,
 				Computed: true,
@@ -118,10 +111,7 @@ func resourceAwsLambdaFunction() *schema.Resource {
 			},
 			"source_code_hash": &schema.Schema{
 				Type:     schema.TypeString,
-				Computed: true,
-			},
-			"remote_code_hash": &schema.Schema{
-				Type:     schema.TypeString,
+				Optional: true,
 				Computed: true,
 			},
 		},
@@ -140,13 +130,12 @@ func resourceAwsLambdaFunctionCreate(d *schema.ResourceData, meta interface{}) e
 
 	var functionCode *lambda.FunctionCode
 	if v, ok := d.GetOk("filename"); ok {
-		zipfile, shaSum, err := loadLocalZipFile(v.(string))
+		file, err := loadFileContent(v.(string))
 		if err != nil {
-			return err
+			return fmt.Errorf("Unable to load %q: %s", v.(string), err)
 		}
-		d.Set("source_code_hash", shaSum)
 		functionCode = &lambda.FunctionCode{
-			ZipFile: zipfile,
+			ZipFile: file,
 		}
 	} else {
 		s3Bucket, bucketOk := d.GetOk("s3_bucket")
@@ -257,26 +246,7 @@ func resourceAwsLambdaFunctionRead(d *schema.ResourceData, meta interface{}) err
 	if config := flattenLambdaVpcConfigResponse(function.VpcConfig); len(config) > 0 {
 		d.Set("vpc_config", config)
 	}
-
-	// Compare code hashes, and see if an update is required to code. If there
-	// is, set the "update_code" attribute.
-
-	remoteSum, err := decodeBase64(*function.CodeSha256)
-	if err != nil {
-		return err
-	}
-	_, localSum, err := loadLocalZipFile(d.Get("filename").(string))
-	if err != nil {
-		return err
-	}
-	d.Set("remote_code_hash", remoteSum)
-	d.Set("source_code_hash", localSum)
-
-	if remoteSum != localSum {
-		d.Set("update_code", true)
-	} else {
-		d.Set("update_code", false)
-	}
+	d.Set("source_code_hash", function.CodeSha256)
 
 	return nil
 }
@@ -314,16 +284,12 @@ func resourceAwsLambdaFunctionUpdate(d *schema.ResourceData, meta interface{}) e
 	}
 
 	codeUpdate := false
-	if sourceHash, ok := d.GetOk("source_code_hash"); ok {
-		zipfile, shaSum, err := loadLocalZipFile(d.Get("filename").(string))
+	if v, ok := d.GetOk("filename"); ok && d.HasChange("source_code_hash") {
+		file, err := loadFileContent(v.(string))
 		if err != nil {
-			return err
-		}
-		if sourceHash != shaSum {
-			d.SetPartial("filename")
-			d.SetPartial("source_code_hash")
+			return fmt.Errorf("Unable to load %q: %s", v.(string), err)
 		}
-		codeReq.ZipFile = zipfile
+		codeReq.ZipFile = file
 		codeUpdate = true
 	}
 	if d.HasChange("s3_bucket") || d.HasChange("s3_key") || d.HasChange("s3_object_version") {
@@ -390,27 +356,17 @@ func resourceAwsLambdaFunctionUpdate(d *schema.ResourceData, meta interface{}) e
 	return resourceAwsLambdaFunctionRead(d, meta)
 }
 
-// loads the local ZIP data and the SHA sum of the data.
-func loadLocalZipFile(v string) ([]byte, string, error) {
+// loadFileContent returns contents of a file in a given path
+func loadFileContent(v string) ([]byte, error) {
 	filename, err := homedir.Expand(v)
 	if err != nil {
-		return nil, "", err
-	}
-	zipfile, err := ioutil.ReadFile(filename)
-	if err != nil {
-		return nil, "", err
+		return nil, err
 	}
-	sum := sha256.Sum256(zipfile)
-	return zipfile, fmt.Sprintf("%x", sum), nil
-}
-
-// Decodes a base64 string to a string.
-func decodeBase64(s string) (string, error) {
-	sum, err := base64.StdEncoding.DecodeString(s)
+	fileContent, err := ioutil.ReadFile(filename)
 	if err != nil {
-		return "", err
+		return nil, err
 	}
-	return fmt.Sprintf("%x", sum), nil
+	return fileContent, nil
 }
 
 func validateVPCConfig(v interface{}) (map[string]interface{}, error) {