luci_deploy: Enable loading "index.yaml" directly.

deploytool/api/deploy/util.go

Index: deploytool/api/deploy/util.go
diff --git a/deploytool/api/deploy/util.go b/deploytool/api/deploy/util.go
index 66e1cfa3049e4c33fecb75d57c3ec6ba68dbf177..9adbe2508d1a70ee6d33623022d544669e965848 100644
--- a/deploytool/api/deploy/util.go
+++ b/deploytool/api/deploy/util.go
@@ -6,6 +6,8 @@ package deploy
 
 import (
 	"fmt"
+
+	"github.com/luci/luci-go/common/errors"
 )
 
 // AppYAMLString returns the "app.yaml" string for this option.
@@ -36,7 +38,7 @@ func (v AppEngineModule_Handler_SecureOption) AppYAMLString() string {
 	}
 }
 
-// AppYAMLString returns the "app.yaml" string for this option.
+// AppYAMLString returns the "index.yaml" string for this option.
 func (v AppEngineResources_Index_Direction) AppYAMLString() string {
 	switch v {
 	case AppEngineResources_Index_ASCENDING:
@@ -48,6 +50,26 @@ func (v AppEngineResources_Index_Direction) AppYAMLString() string {
 	}
 }
 
+// IndexDirectionFromAppYAMLString returns the
+// AppEngineResources_Index_Direction value associated with the given
+// "index.yaml" strnig value.
+//
+// This is a reverse of the AppEngineResources_Index_Direction's AppYAMLString.
+//
+// If the direction value is not recognized, an error will be returned.
+func IndexDirectionFromAppYAMLString(v string) (AppEngineResources_Index_Direction, error) {
+	switch v {
+	case "asc", "":
+		return AppEngineResources_Index_ASCENDING, nil
+
+	case "desc":
+		return AppEngineResources_Index_DESCENDING, nil
+
+	default:
+		return 0, errors.Reason("invalid index direction %(value)q").D("value", v).Err()
+	}
+}
+
 // KubeString returns the Kubernetes "restartPolicy" field string for the
 // enumeration value.
 func (v KubernetesPod_RestartPolicy) KubeString() string {