Milo: Use luci-config for storing buildbot acls

milo/appengine/common/config.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 common
 
 import (
+        "errors"
         "fmt"
 
-        ds "github.com/luci/gae/service/datastore"
+        "github.com/luci/gae/service/datastore"
         "github.com/luci/gae/service/info"
         "github.com/luci/luci-go/common/logging"
         "github.com/luci/luci-go/luci_config/server/cfgclient"
         "github.com/luci/luci-go/luci_config/server/cfgclient/textproto"
         "github.com/luci/luci-go/milo/common/config"
 
         "github.com/golang/protobuf/proto"
         "golang.org/x/net/context"
 )
 
 // Project is a LUCI project.
 type Project struct {
         // The ID of the project, as per self defined.  This is not the luci-cfg
         // name.
         ID string `gae:"$id"`
         // The luci-cfg name of the project.
         Name string
         // The Project data in protobuf binary format.
         Data []byte `gae:",noindex"`
 }
 
-// Update internal configuration based off luci-cfg.
+var errNotConfigured = errors.New("milo instance is missing settings.cfg")
+
+// GetServiceConfig returns the service (aka global) config for the current
+// instance of Milo.
+func GetSettings(c context.Context) (*config.Settings, error) {
+        cs := cfgclient.CurrentServiceConfigSet(c)
+        var content string
+        // Our global config name is called settings.cfg.
+        err := cfgclient.Get(c, cfgclient.AsService, cs, "settings.cfg", cfgclient.String(&content), nil)

[nodir, 2017/03/20 21:41:32]

this API call should be used in serving path. LuciConfig has very low
reliability and should be used only in background tasks.

[hinoka, 2017/03/20 22:19:26]

Done.

+        switch err {
+        case cfgclient.ErrNoConfig:
+                return nil, errNotConfigured

[nodir, 2017/03/20 21:41:32]

this will cause http500s on all requests, I assume?
Why not return an empty Settings struct?

[hinoka, 2017/03/20 22:19:26]

Done.

+        case nil:
+                // continue
+        default:
+                return nil, err
+        }
+        msg := &config.Settings{}
+        err = proto.UnmarshalText(content, msg)

[nodir, 2017/03/20 21:41:32]

make sure the config is stored in binary so we can rollback milo version

[hinoka, 2017/03/20 22:19:26]

Done.

+        return msg, err
+}
+
+// UpdateProjectConfigs internal project configuration based off luci-cfg.
 // update updates Milo's configuration based off luci config.  This includes
 // scanning through all project and extract all console configs.
-func Update(c context.Context) error {
+func UpdateProjectConfigs(c context.Context) error {
         cfgName := info.AppID(c) + ".cfg"
 
         var (
                 configs []*config.Project
                 metas   []*cfgclient.Meta
         )
         if err := cfgclient.Projects(c, cfgclient.AsService, cfgName, textproto.Slice(&configs), &metas); err != nil {
                 logging.WithError(err).Errorf(c, "Encountered error while getting project config for %s", cfgName)
                 return err
         }
@@ skipping 19 matching lines @@
                 if err != nil {
                         return err
                 }
         }
 
         // Now load all the data into the datastore.
         projs := make([]*Project, 0, len(projects))
         for _, proj := range projects {
                 projs = append(projs, proj)
         }
-        if err := ds.Put(c, projs); err != nil {
+        if err := datastore.Put(c, projs); err != nil {
                 return err
         }
 
         // Delete entries that no longer exist.
-        q := ds.NewQuery("Project").KeysOnly(true)
+        q := datastore.NewQuery("Project").KeysOnly(true)
         allProjs := []Project{}
-        ds.GetAll(c, q, &allProjs)
+        datastore.GetAll(c, q, &allProjs)
         toDelete := []Project{}
         for _, proj := range allProjs {
                 if _, ok := projects[proj.ID]; !ok {
                         toDelete = append(toDelete, proj)
                 }
         }
-        ds.Delete(c, toDelete)
+        datastore.Delete(c, toDelete)
 
         return nil
 }
 
 // GetAllProjects returns all registered projects.
 func GetAllProjects(c context.Context) ([]*config.Project, error) {
-        q := ds.NewQuery("Project")
+        q := datastore.NewQuery("Project")
         q.Order("ID")
 
         ps := []*Project{}
-        err := ds.GetAll(c, q, &ps)
+        err := datastore.GetAll(c, q, &ps)
         if err != nil {
                 return nil, err
         }
         results := make([]*config.Project, len(ps))
         for i, p := range ps {
                 results[i] = &config.Project{}
                 if err := proto.Unmarshal(p.Data, results[i]); err != nil {
                         return nil, err
                 }
         }
         return results, nil
 }
 
 // GetProject returns the requested project.
 func GetProject(c context.Context, projName string) (*config.Project, error) {
         // Next, Try datastore
         p := Project{ID: projName}
-        if err := ds.Get(c, &p); err != nil {
+        if err := datastore.Get(c, &p); err != nil {
                 return nil, err
         }
         mp := config.Project{}
         if err := proto.Unmarshal(p.Data, &mp); err != nil {
                 return nil, err
         }
 
         return &mp, nil
 }
 
 // GetConsole returns the requested console instance.
 func GetConsole(c context.Context, projName, consoleName string) (*config.Console, error) {
         p, err := GetProject(c, projName)
         if err != nil {
                 return nil, err
         }
         for _, cs := range p.Consoles {
                 if cs.Name == consoleName {
                         return cs, nil
                 }
         }
         return nil, fmt.Errorf("Console %s not found in project %s", consoleName, projName)
 }