Add server/cache support to gaeconfig.

dm/appengine/distributor/registry.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 distributor
 
 import (
         "errors"
         "fmt"
         "reflect"
 
-        "github.com/golang/protobuf/proto"
         "github.com/luci/gae/service/info"
-        "github.com/luci/luci-go/common/config"
         "github.com/luci/luci-go/common/logging"
         "github.com/luci/luci-go/dm/api/distributor"
         "github.com/luci/luci-go/dm/api/service/v1"
+        "github.com/luci/luci-go/luci_config/server/cfgclient"
+        "github.com/luci/luci-go/luci_config/server/cfgclient/textproto"
         "github.com/luci/luci-go/tumble"
+
+        "github.com/golang/protobuf/proto"
+
         "golang.org/x/net/context"
 )
 
 var regKey = "holds a DM Distributor Registry"
 
 // WithRegistry adds the registry to the Context.
 func WithRegistry(c context.Context, r Registry) context.Context {
         if r == nil {
                 panic(errors.New("you may not use WithRegistry on a nil Registry"))
         }
@@ skipping 86 matching lines @@
                 return nil, "", fmt.Errorf("unknown distributor type %T", cfg.Content)
         }
 
         d, err = fn(c, cfg)
         return
 }
 
 // loadConfig loads the named distributor configuration from luci-config,
 // possibly using the in-memory or memcache version.
 func loadConfig(c context.Context, cfgName string) (ret *Config, err error) {
-        aid := info.TrimmedAppID(c)
-        distCfgObj, err := config.GetConfig(c, fmt.Sprintf("services/%s", aid), "distributors.cfg", false)
-        if err != nil {
+        configSet := cfgclient.CurrentServiceConfigSet(c)
+
+        var (
+                distCfg distributor.Config
+                meta    cfgclient.Meta
+        )
+        if err = cfgclient.Get(c, cfgclient.AsService, configSet, "distributors.cfg", textproto.Message(&distCfg), &meta); err != nil {
                 return
         }
 
-        cfgVersion := distCfgObj.Revision
-        distCfg := &distributor.Config{}
-        if err = proto.UnmarshalText(distCfgObj.Content, distCfg); err != nil {
-                return
-        }
-
+        cfgVersion := meta.Revision
         cfg, ok := distCfg.DistributorConfigs[cfgName]
         if !ok {
                 err = fmt.Errorf("unknown distributor configuration: %q", cfgName)
                 return
         }
         if alias := cfg.GetAlias(); alias != nil {
                 cfg, ok = distCfg.DistributorConfigs[alias.OtherConfig]
                 if !ok {
                         err = fmt.Errorf("unknown distributor configuration: %q (via alias %q)", cfgName, alias.OtherConfig)
                         return
@@ skipping 16 matching lines @@
         implConfig := dVal.Elem().Field(0).Interface().(proto.Message)
 
         ret = &Config{
                 info.DefaultVersionHostname(c),
                 cfgName,
                 cfgVersion,
                 implConfig,
         }
         return
 }