Added support for updating a cloud storage object using source field (#362)

google/resource_storage_bucket_object.go

@@ -2,8 +2,11 @@ package google
 
 import (
 	"bytes"
+	"crypto/md5"
+	"encoding/base64"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"log"
 	"os"
 
@@ -92,6 +95,9 @@ func resourceStorageBucketObject() *schema.Resource {
 				Optional:      true,
 				ForceNew:      true,
 				ConflictsWith: []string{"content"},
+				StateFunc: func(src interface{}) string {
+					return fileNameWithMd5(src.(string))
+				},
 			},
 
 			"storage_class": &schema.Schema{
@@ -108,6 +114,20 @@ func objectGetId(object *storage.Object) string {
 	return object.Bucket + "-" + object.Name
 }
 
+func fileNameWithMd5(filename string) string {
+	data, err := ioutil.ReadFile(filename)
+	if err != nil {
+		log.Printf("[WARN] Failed to read source file %s. Will not compute md5 to store in state", filename)
+		return filename
+	}
+
+	h := md5.New()
+	h.Write(data)
+	md5 := base64.StdEncoding.EncodeToString(h.Sum(nil))
+
+	return filename + ":" + md5
+}
+
 func resourceStorageBucketObjectCreate(d *schema.ResourceData, meta interface{}) error {
 	config := meta.(*Config)
 

google/resource_storage_bucket_object_test.go

@@ -5,6 +5,7 @@ import (
 	"encoding/base64"
 	"fmt"
 	"io/ioutil"
+	"os"
 	"testing"
 
 	"github.com/hashicorp/terraform/helper/resource"
@@ -46,6 +47,51 @@ func TestAccGoogleStorageObject_basic(t *testing.T) {
 	})
 }
 
+func TestAccGoogleStorageObject_recreate(t *testing.T) {
+	t.Parallel()
+
+	bucketName := testBucketName()
+
+	writeFile := func(name string, data []byte) string {
+		h := md5.New()
+		h.Write(data)
+		data_md5 := base64.StdEncoding.EncodeToString(h.Sum(nil))
+
+		ioutil.WriteFile(name, data, 0644)
+		return data_md5
+	}
+	data_md5 := writeFile(tf.Name(), []byte("data data data"))
+	updated_data_md5 := writeFile(tf.Name()+".update", []byte("datum"))
+
+	resource.Test(t, resource.TestCase{
+		PreCheck: func() {
+			if err != nil {
+				panic(err)
+			}
+			testAccPreCheck(t)
+		},
+		Providers:    testAccProviders,
+		CheckDestroy: testAccGoogleStorageObjectDestroy,
+		Steps: []resource.TestStep{
+			resource.TestStep{
+				Config: testGoogleStorageBucketsObjectBasic(bucketName),
+				Check:  testAccCheckGoogleStorageObject(bucketName, objectName, data_md5),
+			},
+			resource.TestStep{
+				PreConfig: func() {
+					updateName := tf.Name() + ".update"
+					err := os.Rename(updateName, tf.Name())
+					if err != nil {
+						t.Errorf("Failed to rename %s to %s", updateName, tf.Name())
+					}
+				},
+				Config: testGoogleStorageBucketsObjectBasic(bucketName),
+				Check:  testAccCheckGoogleStorageObject(bucketName, objectName, updated_data_md5),
+			},
+		},
+	})
+}
+
 func TestAccGoogleStorageObject_content(t *testing.T) {
 	t.Parallel()