Milo: Add themed page for errors

milo/appengine/buildbot/build.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 buildbot
 
 import (
         "encoding/json"
         "fmt"
         "io/ioutil"
         "net/http"
         "path/filepath"
         "sort"
         "strings"
         "time"
 
         ds "github.com/luci/gae/service/datastore"
         "github.com/luci/luci-go/common/data/stringset"
         "github.com/luci/luci-go/common/logging"
         "github.com/luci/luci-go/milo/api/resp"
         "github.com/luci/luci-go/milo/appengine/settings"
         "github.com/luci/luci-go/milo/common/miloerror"
+        "github.com/luci/luci-go/server/auth"
+        "github.com/luci/luci-go/server/auth/identity"
         "golang.org/x/net/context"
 )
 
 var errBuildNotFound = miloerror.Error{
         Message: "Build not found",
         Code:    http.StatusNotFound,
 }
 
 // getBuild fetches a buildbot build from the datastore and checks ACLs.
+// The return code matches the master responses, that is:
+// User not logged in, master found, master public: 200
+// User not logged in, master not found: 401
+// User not logged in, master internal: 401
+// User logged in, master found, master internal: 200
+// User logged in, master not found: 404
+// User logged in, master found, master internal: 404
+// Other error: 500
 func getBuild(c context.Context, master, builder string, buildNum int) (*buildbotBuild, error) {
         result := &buildbotBuild{
                 Master:      master,
                 Buildername: builder,
                 Number:      buildNum,
         }
+        cu := auth.CurrentUser(c)
 
         err := ds.Get(c, result)
         switch {
         case err == ds.ErrNoSuchEntity:
-                return nil, errBuildNotFound
+                if cu.Identity == identity.AnonymousIdentity {
+                        return nil, errNotAuth
+                } else {
+                        return nil, errBuildNotFound
+                }
         case err != nil:
                 return nil, err
         }
         if result.Internal {
                 allowed, err := settings.IsAllowedInternal(c)
                 if err != nil {
                         return nil, err
                 }
                 if !allowed {
-                        return nil, errBuildNotFound
+                        if cu.Identity == identity.AnonymousIdentity {
+                                return nil, errNotAuth
+                        } else {
+                                return nil, errBuildNotFound
+                        }
                 }
         }
 
         return result, nil
 }
 
 // result2Status translates a buildbot result integer into a resp.Status.
 func result2Status(s *int) (status resp.Status) {
         if s == nil {
                 return resp.Running
@@ skipping 425 matching lines @@
 
         // TODO(hinoka): Do all fields concurrently.
         return &resp.MiloBuild{
                 SourceStamp:   sourcestamp(c, b),
                 Summary:       summary(c, b),
                 Components:    components(b),
                 PropertyGroup: properties(b),
                 Blame:         blame(b),
         }, nil
 }