Milo: Add ts_mon metrics for master json datastore success

milo/appengine/buildbot/pubsub.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"
         "compress/zlib"
         "encoding/base64"
         "encoding/json"
+        "fmt"
         "net/http"
         "strings"
         "time"
 
         ds "github.com/luci/gae/service/datastore"
         "github.com/luci/luci-go/common/clock"
         "github.com/luci/luci-go/common/iotools"
         "github.com/luci/luci-go/common/logging"
         "github.com/luci/luci-go/server/router"
 
@@ skipping 13 matching lines @@
         buildCounter = metric.NewCounter(
                 "luci/milo/buildbot_pubsub/builds",
                 "The number of buildbot builds received by Milo from PubSub",
                 nil,
                 field.Bool("internal"),
                 field.String("master"),
                 field.String("builder"),
                 field.Bool("finished"),
                 // Status can be one of 3 options.  "New", "Replaced", "Rejected".
                 field.String("status"))
+
+        masterCounter = metric.NewCounter(
+                "luci/milo/buildbot_pubsub/masters",
+                "The number of buildbot master jsons received by Milo from PubSub",
+                nil,
+                field.Bool("internal"),
+                field.String("master"),
+                // Status can be one of 2 options.  "success", "failure".
+                field.String("status"))
 )
 
 type pubSubMessage struct {
         Attributes map[string]string `json:"attributes"`
         Data       string            `json:"data"`
         MessageID  string            `json:"message_id"`
 }
 
 type pubSubSubscription struct {
         Message      pubSubMessage `json:"message"`
@@ skipping 84 matching lines @@
                                 bm.Builds = append(bm.Builds, build)
                                 slave.RunningbuildsMap[build.Buildername] = append(
                                         slave.RunningbuildsMap[build.Buildername], build.Number)
                         }
                         slave.Runningbuilds = nil
                 }
         }
         return bm.Builds, bm.Master, nil
 }
 
-// getOSInfo fetches the os family and version of hte build from the
-// master json on a best-effort basis.
+// getOSInfo fetches the os family and version of the slave the build was
+// running on from the master json on a best-effort basis.
 func getOSInfo(c context.Context, b *buildbotBuild, m *buildbotMaster) (
         family, version string) {
         // Fetch the master info from datastore if not provided.
         if m.Name == "" {
                 logging.Infof(c, "Fetching info for master %s", b.Master)
                 entry := buildbotMasterEntry{Name: b.Master}
                 err := ds.Get(c, &entry)
                 if err != nil {
                         logging.WithError(err).Errorf(
                                 c, "Encountered error while fetching entry for %s", b.Master)
@@ skipping 43 matching lines @@
         b.Finished = true
         b.Results = &results
         b.Currentstep = nil
         b.Text = append(b.Text, "Build expired on Milo")
         return ds.Put(c, b)
 }
 
 func doMaster(c context.Context, master *buildbotMaster, internal bool) int {
         // Store the master json into the datastore.
         err := putDSMasterJSON(c, master, internal)
+        fullname := fmt.Sprintf("master.%s", master.Name)
         if err != nil {
                 logging.WithError(err).Errorf(
                         c, "Could not save master in datastore %s", err)
+                masterCounter.Add(c, 1, internal, fullname, "failure")
                 // This is transient, we do want PubSub to retry.
                 return 500
         }
+        masterCounter.Add(c, 1, internal, fullname, "success")
 
         // Extract current builds data out of the master json, and use it to
         // clean up expired builds.
         q := ds.NewQuery("buildbotBuild").
                 Eq("finished", false).
                 Eq("master", master.Name)
         builds := []*buildbotBuild{}
         err = ds.GetAll(c, q, &builds)
         if err != nil {
                 logging.WithError(err).Errorf(c, "Could not load current builds from master %s",
@@ skipping 153 matching lines @@
 
         }
         if master != nil {
                 code := doMaster(c, master, internal)
                 if code != 0 {
                         return code
                 }
         }
         return 200
 }