token-server: Warmup some local caches in /_ah/warmup.

tokenserver/appengine/impl/delegation/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 delegation
 
 import (
         "fmt"
         "strings"
         "time"
@@ skipping 79 matching lines @@
         cfg := &DelegationConfig{}
         switch err := ds.Get(c, cfg); {
         case err == ds.ErrNoSuchEntity:
                 return cfg, nil
         case err != nil:
                 return nil, errors.WrapTransient(err)
         }
         return cfg, nil
 }
 
-// DelegationConfigLoader constructs a function that lazy-loads delegation
-// config and keeps it cached in memory, refreshing the cached copy each minute.
+// DelegationConfigLoader lazy-loads delegation config and keeps it cached in
+// memory, refreshing the cached copy each minute.
 //
 // Used as MintDelegationTokenRPC.ConfigLoader implementation in prod.
-func DelegationConfigLoader() func(context.Context) (*DelegationConfig, error) {
+var DelegationConfigLoader = delegationConfigLoader()
+
+// delegationConfigLoader constructs a function that lazy-loads delegation
+// config and keeps it cached in memory, refreshing the cached copy each minute.
+func delegationConfigLoader() func(context.Context) (*DelegationConfig, error) {
         slot := lazyslot.Slot{
                 Fetcher: func(c context.Context, prev lazyslot.Value) (lazyslot.Value, error) {
                         newCfg, err := FetchDelegationConfig(c)
                         if err != nil {
                                 return lazyslot.Value{}, err
                         }
 
                         // Reuse existing unpacked validated config if the revision didn't change.
                         prevCfg, _ := prev.Value.(*DelegationConfig)
                         if prevCfg != nil && prevCfg.Revision == newCfg.Revision {
@@ skipping 184 matching lines @@
                 return false, nil
         }
 
         // Rule's allowed targets is superset of requested targets?
         if !rule.services.IsSuperset(q.Services) {
                 return false, nil
         }
 
         return true, nil
 }