Compute content_base64 for google_storage_bucket_object_content

This returns the same content present in the return object but exposed
by using Base64 encoding. This is mostly useful for reading binary
content.

Our particular use case is to push the content of a WASM file to a
Fastly Compute@Edge service. But this is also useful for other
serverless services like AWS Lambda as well.

This alongside including the hash sums for the source object content
proposed in
hashicorp/terraform-provider-google#13002,
would allow us pushing content directly from Google Storage Object
Content data source to Fastly Compute@Edge. AWS Lambda also uses the
same version/content discrimination method of sending the content hash
sum within the `source_code_hash` parameter.

Sign-off-by: Gorka Lerchundi Osa <glertxundi@gmail.com>

mmv1/third_party/terraform/data_sources/data_source_storage_bucket_object_content.go

@@ -1,6 +1,7 @@
 package google
 
 import (
+	"encoding/base64"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -16,6 +17,13 @@ func dataSourceGoogleStorageBucketObjectContent() *schema.Resource {
 	addRequiredFieldsToSchema(dsSchema, "bucket")
 	addRequiredFieldsToSchema(dsSchema, "name")
 	addOptionalFieldsToSchema(dsSchema, "content")
+	dsSchema["content_base64"] = &schema.Schema{
+		Type:        schema.TypeString,
+		Description: "Base64 encoded version of the object content. Use this when dealing with binary data.",
+		Computed:    true,
+		Optional:    false,
+		Required:    true,
+	}
 
 	return &schema.Resource{
 		Read:   dataSourceGoogleStorageBucketObjectContentRead,
@@ -40,22 +48,25 @@ func dataSourceGoogleStorageBucketObjectContentRead(d *schema.ResourceData, meta
 	if err != nil {
 		return fmt.Errorf("Error downloading storage bucket object: %s", err)
 	}
-
 	defer res.Body.Close()
-	var bodyString string
 
+	var bodyBytes []byte
 	if res.StatusCode == http.StatusOK {
-		bodyBytes, err := ioutil.ReadAll(res.Body)
+		candidateBodyBytes, err := ioutil.ReadAll(res.Body)
 		if err != nil {
 			return fmt.Errorf("Error reading all  from res.Body: %s", err)
 		}
-		bodyString = string(bodyBytes)
+		bodyBytes = candidateBodyBytes
 	}
 
-	if err := d.Set("content", bodyString); err != nil {
+	if err := d.Set("content", string(bodyBytes)); err != nil {
 		return fmt.Errorf("Error setting content: %s", err)
 	}
 
+	if err := d.Set("content_base64", base64.StdEncoding.EncodeToString(bodyBytes)); err != nil {
+		return fmt.Errorf("Error setting content_base64: %s", err)
+	}
+
 	d.SetId(bucket + "-" + name)
 	return nil
 }

mmv1/third_party/terraform/tests/data_source_storage_bucket_object_content_test.go

@@ -1,6 +1,7 @@
 package google
 
 import (
+	"encoding/base64"
 	"fmt"
 	"testing"
 
@@ -21,6 +22,8 @@ func TestAccDataSourceStorageBucketObjectContent_Basic(t *testing.T) {
 				Check: resource.ComposeTestCheckFunc(
 					resource.TestCheckResourceAttrSet("data.google_storage_bucket_object_content.default", "content"),
 					resource.TestCheckResourceAttr("data.google_storage_bucket_object_content.default", "content", content),
+					resource.TestCheckResourceAttrSet("data.google_storage_bucket_object_content.default", "content_base64"),
+					resource.TestCheckResourceAttr("data.google_storage_bucket_object_content.default", "content_base64", base64.StdEncoding.EncodeToString([]byte(content))),
 				),
 			},
 		},

mmv1/third_party/terraform/website/docs/d/storage_bucket_object_content.html.markdown

@@ -42,4 +42,10 @@ The following arguments are supported:
 
 The following attributes are exported:
 
-* `content` - (Computed) [Content-Language](https://tools.ietf.org/html/rfc7231#section-3.1.3.2) of the object content.
+* `content` - (Computed) Raw content of the object content, assumed by Terraform
+  to be UTF-8 encoded string. Files that do not contain UTF-8 text will have
+  invalid UTF-8 sequences in `content` replaced with the Unicode replacement
+  character.
+
+* `content_base64` - (Computed) Base64 encoded version of the object content.
+  Use this when dealing with binary data.