Add server/cache support to gaeconfig.

dm/api/template/loader.go

 // Copyright 2016 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package dmTemplate
 
 import (
         "fmt"
 
         "golang.org/x/net/context"
 
-        "github.com/luci/luci-go/common/config"
         "github.com/luci/luci-go/common/data/text/templateproto"
-        "github.com/luci/luci-go/common/proto"
         dm "github.com/luci/luci-go/dm/api/service/v1"
+        "github.com/luci/luci-go/server/config"
+        "github.com/luci/luci-go/server/config/textproto"
 )
 
 // LoadFile loads a File by configSet and path.
 func LoadFile(c context.Context, project, ref string) (file *File, vers string, err error) {
         cfgSet := "projects/" + project
         if ref != "" {
                 cfgSet += "/" + ref
         }
-        templateData, err := config.GetConfig(c, cfgSet, "dm/quest_templates.cfg", false)
-        if err != nil {
+
+        file = &File{}
+        var meta config.Meta
+        if err = config.Get(c, config.AsService, cfgSet, "dm/quest_templates.cfg", textproto.Message(file), &meta); err != nil {
                 return
         }
-        file = &File{}
-        vers = templateData.ContentHash
-        err = proto.UnmarshalTextML(templateData.Content, file)
-        if err != nil {
-                return
-        }
+        vers = meta.ContentHash
         err = file.Normalize()
         return
 }
 
 // Render renders the specified template with the given parameters.
 func (f *File) Render(spec *templateproto.Specifier) (*dm.Quest_Desc, error) {
         t := f.Template[spec.TemplateName]
         params, err := t.Parameters.Render(spec.Params)
         if err != nil {
                 return nil, fmt.Errorf("rendering %q: field distributor parameters: %s", spec.TemplateName, err)
         }
         distribParams, err := t.DistributorParameters.Render(spec.Params)
         if err != nil {
                 return nil, fmt.Errorf("rendering %q: field distributor parameters: %s", spec.TemplateName, err)
         }
         return &dm.Quest_Desc{
                 DistributorConfigName: t.DistributorConfigName,
                 Parameters:            params,
                 DistributorParameters: distribParams,
                 Meta: t.Meta,
         }, nil
 }