Milo: Use custom config caching layer

milo/appengine/buildbucket/builder.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 buildbucket
 
 import (
         "encoding/json"
         "fmt"
         "net/url"
@@ skipping 211 matching lines @@
 
 type builderQuery struct {
         Bucket  string
         Builder string
         Limit   int
 }
 
 // builderImpl is the implementation for getting a milo builder page from buildbucket.
 // if maxCompletedBuilds < 0, 25 is used.
 func builderImpl(c context.Context, q builderQuery) (*resp.Builder, error) {
-        settings, err := common.GetSettings(c)
-        if err != nil {
-                logging.WithError(err).Errorf(c, "failed to get settings")
-                return nil, err
-        }
+        settings := common.GetSettings(c)
         if settings.Buildbucket == nil || settings.Buildbucket.Host == "" {
-                logging.WithError(err).Errorf(c, "missing buildbucket settings")
+                logging.Errorf(c, "missing buildbucket settings")
                 return nil, errors.New("missing buildbucket settings")
         }
         host := settings.Buildbucket.Host
 
         if q.Limit < 0 {
                 q.Limit = 20
         }
 
         result := &resp.Builder{
                 Name: q.Builder,
@@ skipping 42 matching lines @@
         return time.Unix(microseconds/1e6, microseconds%1e6*1000).UTC()
 }
 
 type newBuildsFirst []*resp.BuildSummary
 
 func (a newBuildsFirst) Len() int      { return len(a) }
 func (a newBuildsFirst) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
 func (a newBuildsFirst) Less(i, j int) bool {
         return a[i].PendingTime.Started.After(a[j].PendingTime.Started)
 }