Milo: pRPC endpoint for getting Buildbot master data

milo/appengine/buildbot/master.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 (
         "bytes"
         "compress/gzip"
         "encoding/json"
         "fmt"
+        "net/http"
         "sort"
         "time"
 
         "github.com/luci/gae/service/datastore"
         "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"
 
         "golang.org/x/net/context"
 )
 
 func decodeMasterEntry(
         c context.Context, entry *buildbotMasterEntry, master *buildbotMaster) error {
 
         reader, err := gzip.NewReader(bytes.NewReader(entry.Data))
         if err != nil {
                 return err
         }
         defer reader.Close()
         if err = json.NewDecoder(reader).Decode(master); err != nil {
                 return err
         }
         return nil
 }
 
+var errMasterNotFound = miloerror.Error{
+        Message: "Master not found",
+        Code:    http.StatusNotFound,
+}
+
+// getMasterEntry feches the named master and does an ACL check on the
+// current user.
+func getMasterEntry(c context.Context, name string) (*buildbotMasterEntry, error) {
+        entry := buildbotMasterEntry{Name: name}
+        ds := datastore.Get(c)
+        err := ds.Get(&entry)
+        switch {
+        case err == datastore.ErrNoSuchEntity:
+                return nil, errMasterNotFound
+        case err != nil:
+                logging.WithError(err).Errorf(
+                        c, "Encountered error while fetching entry for %s:\n%s", name, err)
+                return nil, err
+        }
+
+        // Do the ACL check if the entry is internal.
+        if entry.Internal {
+                allowed, err := settings.IsAllowedInternal(c)
+                if err != nil {
+                        return nil, err
+                }
+                if !allowed {
+                        return nil, errMasterNotFound
+                }
+        }
+
+        return &entry, nil
+}
+
 // 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, t time.Time, err error) {
         master = &buildbotMaster{}
-        entry := buildbotMasterEntry{Name: name}
-        ds := datastore.Get(c)
-        err = ds.Get(&entry)
+        entry, err := getMasterEntry(c, name)
         if err != nil {
-                logging.WithError(err).Errorf(
-                        c, "Encountered error while fetching entry for %s:\n%s", name, err)
                 return
         }
-        internal = entry.Internal
         t = entry.Modified
-        err = decodeMasterEntry(c, &entry, master)
+        err = decodeMasterEntry(c, entry, master)
         return
 }
 
 // GetAllBuilders returns a resp.Module object containing all known masters
 // and builders.
 func GetAllBuilders(c context.Context) (*resp.Module, error) {
         result := &resp.Module{Name: "Buildbot"}
         // Fetch all Master entries from datastore
         ds := datastore.Get(c)
         q := datastore.NewQuery("buildbotMasterEntry")
@@ skipping 37 matching lines @@
                                 Label: bn,
                                 // Go templates escapes this for us, and also
                                 // slashes are not allowed in builder names.
                                 URL: fmt.Sprintf("/buildbot/%s/%s", entry.Name, bn),
                         })
                 }
                 result.Masters = append(result.Masters, ml)
         }
         return result, nil
 }