Milo: Move instance configuration to luci-config

milo/appengine/swarming/buildinfo.go

 // Copyright 2017 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 swarming
 
 import (
         "strconv"
         "strings"
         "unicode/utf8"
@@ skipping 19 matching lines @@
         bl buildLoader
 
         // swarmingServiceFunc returns a swarmingService instance for the supplied
         // parameters.
         //
         // If nil, a production fetcher will be generated.
         swarmingServiceFunc func(c context.Context, host string) (swarmingService, error)
 }
 
 func (p *BuildInfoProvider) newSwarmingService(c context.Context, host string) (swarmingService, error) {
-        fn := p.swarmingServiceFunc
-        if fn == nil {
-                fn = getSwarmingService
+        if p.swarmingServiceFunc == nil {
+                return newProdService(c, host)
         }
-        return fn(c, host)
+        return p.swarmingServiceFunc(c, host)
 }
 
 // GetBuildInfo resolves a Milo protobuf Step for a given Swarming task.
 func (p *BuildInfoProvider) GetBuildInfo(c context.Context, req *milo.BuildInfoRequest_Swarming,
         projectHint cfgtypes.ProjectName) (*milo.BuildInfoResponse, error) {
 
         // Load the Swarming task (no log content).
         sf, err := p.newSwarmingService(c, req.Host)
         if err != nil {
                 logging.WithError(err).Errorf(c, "Failed to create Swarming fetcher.")
@@ skipping 213 matching lines @@
         lastChar, lastCharSize := utf8.DecodeLastRuneInString(taskID)
         v, err := strconv.ParseUint(string(lastChar), 16, 8)
         if err != nil {
                 return "", errors.Annotate(err).Reason("failed to parse hex from rune: %(rune)r").
                         D("rune", lastChar).
                         Err()
         }
 
         return taskID[:len(taskID)-lastCharSize] + strconv.FormatUint((v|uint64(tryNumber)), 16), nil
 }