Milo: Extract the rietveld information from buildbot.

appengine/cmd/milo/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"
@@ skipping 323 matching lines @@
                         Repo:        c.Repository,
                         Revision:    c.Revision,
                         Description: c.Comments,
                         Title:       strings.Split(c.Comments, "\n")[0],
                         File:        files,
                 })
         }
         return
 }
 
+// sourcestamp extracts the source stamp from various parts of a buildbot build,
+// including the properties.
+func sourcestamp(b *buildbotBuild) *resp.SourceStamp {
+        ss := &resp.SourceStamp{}
+        rietveld := ""
+        issue := int64(-1)
+        // TODO(hinoka): Gerrit URLs.
+        for _, prop := range b.Properties {
+                key := prop[0].(string)
+                value := prop[1]
+                switch key {
+                case "rietveld":
+                        rietveld = value.(string)
+                case "issue":
+                        issue = int64(value.(float64))
+                case "got_revision":
+                        ss.Revision = value.(string)
+                }
+        }

[nodir, 2016/06/28 02:06:44]

This code will panic if user input malformed, we should not panic if user gave
us bad data. Please add checks in type assertions and log erros if type
assertions fail

[Ryan Tseng, 2016/06/28 21:49:31]

Done.

+        if issue != -1 && rietveld == "" {
+                // Default rietveld server
+                rietveld = "https://codereview.chromium.org"

[nodir, 2016/06/28 02:06:44]

Do we have to define defaults in our code? Do we have builds that do not specify
rietveld hostname?

[Ryan Tseng, 2016/06/28 21:49:31]

Not sure, this is just incase.  I'll remove this

+        }
+        if issue != -1 {
+                ss.Changelist = &resp.Link{
+                        Label: fmt.Sprintf("Issue %d", issue),
+                        URL:   fmt.Sprintf("%s/%d", rietveld, issue),

[nodir, 2016/06/28 02:06:44]

What if rietveld ends with /
Trim it 

[Ryan Tseng, 2016/06/28 21:49:31]

Done.

+                }
+        }
+        return ss
+}
+
 func getDebugBuild(c context.Context, builder, buildNum string) (*buildbotBuild, error) {
         fname := fmt.Sprintf("%s.%s.json", builder, buildNum)
         path := filepath.Join("testdata", "buildbot", fname)
         raw, err := ioutil.ReadFile(path)
         if err != nil {
                 return nil, err
         }
         b := &buildbotBuild{}
         return b, json.Unmarshal(raw, b)
 }
 
 // build fetches a buildbot build and translates it into a miloBuild.
 func build(c context.Context, master, builder, buildNum string) (*resp.MiloBuild, error) {
         var b *buildbotBuild
         var err error
         if master == "debug" {
                 b, err = getDebugBuild(c, builder, buildNum)
         } else {
                 b, err = getBuild(c, master, builder, buildNum)
         }
         if err != nil {
                 return nil, err
         }
 
         return &resp.MiloBuild{
+                SourceStamp:   sourcestamp(b),
                 Summary:       summary(b),
                 Components:    components(b),
                 PropertyGroup: properties(b),
                 Blame:         blame(b),
         }, nil
 }