[milo] Refactor all html knowledge out of backends.

milo/buildsource/buildbot/master.go

 // Copyright 2016 The LUCI Authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //      http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 package buildbot
 
 import (
         "bytes"
         "compress/gzip"
         "encoding/json"
         "fmt"
         "sort"
         "time"
 
         ds "github.com/luci/gae/service/datastore"
+        "github.com/luci/luci-go/common/errors"
         "github.com/luci/luci-go/common/logging"
         "github.com/luci/luci-go/milo/api/resp"
         "github.com/luci/luci-go/milo/common"
         "github.com/luci/luci-go/server/auth"
         "github.com/luci/luci-go/server/auth/identity"
 
         "golang.org/x/net/context"
 )
 
 func decodeMasterEntry(
@@ skipping 27 matching lines @@
 
         // We're not logged in, or we can only see public stuff, so see if the master
         // is public.
         if err := ds.Get(c, &buildbotMasterPublic{name}); err == nil {
                 // It exists and is public
                 return nil
         }
 
         if anon {
                 // They need to log in before we can tell them more stuff.
-                return errNotAuth
+                return errors.New("public master not found", common.CodeUnauthorized)
+
         }
 
         // They are logged in but have no access, so tell them it's missing.
-        return errMasterNotFound
+        return errors.New("master not found", common.CodeNotFound)
 }
 
 // getMasterEntry feches the named master and does an ACL check on the
 // current user.
 // It returns:
 func getMasterEntry(c context.Context, name string) (*buildbotMasterEntry, error) {
         if err := canAccessMaster(c, name); err != nil {
                 return nil, err
         }
 
         entry := buildbotMasterEntry{Name: name}
         err := ds.Get(c, &entry)
         if err == ds.ErrNoSuchEntity {
-                err = errMasterNotFound
+                return nil, errors.New("master not found", common.CodeNotFound)
         }
         return &entry, err
 }
 
 // getMasterJSON fetches the latest known buildbot master data and returns
 // the buildbotMaster struct (if found), whether or not it is internal,
 // the last modified time, and an error if not found.
 func getMasterJSON(c context.Context, name string) (
         master *buildbotMaster, internal bool, t time.Time, err error) {
         master = &buildbotMaster{}
@@ skipping 51 matching lines @@
                 for _, bn := range sb {
                         // Go templates escapes this for us, and also
                         // slashes are not allowed in builder names.
                         ml.Builders = append(ml.Builders, *resp.NewLink(
                                 bn, fmt.Sprintf("/buildbot/%s/%s", entry.Name, bn)))
                 }
                 result.BuilderGroups = append(result.BuilderGroups, ml)
         }
         return result, nil
 }