fix(ops/besadii): Pass Build.Author to Buildkite

Extracts author information from the flags passed by Gerrit and moves
them along to Buildkite. This should display the owners of builds
correctly in the UI, rather than marking everything as coming from me.

Change-Id: If9efe5553a13f0dbdb8bf3936c1d341ae5922318

ops/besadii/main.go

@@ -22,6 +22,7 @@ import (
 	"io/ioutil"
 	"log/syslog"
 	"net/http"
+	"net/mail"
 	"os"
 	"os/user"
 	"path"
@@ -58,7 +59,8 @@ type buildTrigger struct {
 	project string
 	ref     string
 	commit  string
-	owner   string
+	author  string
+	email   string
 
 	changeId string
 	patchset string
@@ -198,7 +200,8 @@ func triggerBuild(cfg *config, log *syslog.Writer, trigger *buildTrigger) error
 		Branch: trigger.ref,
 		Env:    env,
 		Author: Author{
-			Name: trigger.owner,
+			Name:  trigger.author,
+			Email: trigger.email,
 		},
 	}
 
@@ -291,6 +294,22 @@ func ignoreFlags(ignore []string) {
 	}
 }
 
+// Extract the username & email from Gerrit's uploader flag and set it
+// on the trigger struct, for display in Buildkite.
+func extractChangeUploader(uploader string, trigger *buildTrigger) error {
+	// Extract the uploader username & email from the input passed by
+	// Gerrit (in RFC 5322 format).
+	addr, err := mail.ParseAddress(uploader)
+	if err != nil {
+		return fmt.Errorf("invalid change uploader (%s): %w", uploader, err)
+	}
+
+	trigger.author = addr.Name
+	trigger.email = addr.Address
+
+	return nil
+}
+
 // Extract the buildtrigger struct out of the flags passed to besadii
 // when invoked as Gerrit's 'patchset-created' hook. This hook is used
 // for triggering CI on in-progress CLs.
@@ -299,21 +318,27 @@ func buildTriggerFromPatchsetCreated(cfg *config) (*buildTrigger, error) {
 	var trigger buildTrigger
 
 	// Information that is only needed for parsing
-	var targetBranch, changeUrl string
+	var targetBranch, changeUrl, uploader string
 
 	flag.StringVar(&trigger.project, "project", "", "Gerrit project")
 	flag.StringVar(&trigger.commit, "commit", "", "commit hash")
-	flag.StringVar(&trigger.owner, "change-owner", "", "change owner")
 	flag.StringVar(&trigger.patchset, "patchset", "", "patchset ID")
 
 	flag.StringVar(&targetBranch, "branch", "", "CL target branch")
 	flag.StringVar(&changeUrl, "change-url", "", "HTTPS URL of change")
+	flag.StringVar(&uploader, "uploader", "", "Change uploader name & email")
 
 	// patchset-created also passes various flags which we don't need.
-	ignoreFlags([]string{"kind", "topic", "change", "uploader", "uploader-username", "change-owner-username"})
+	ignoreFlags([]string{"kind", "topic", "change", "uploader-username", "change-owner", "change-owner-username"})
 
 	flag.Parse()
 
+	// Parse username & email
+	err := extractChangeUploader(uploader, &trigger)
+	if err != nil {
+		return nil, err
+	}
+
 	// If the patchset is not for the HEAD branch of the monorepo, then
 	// we can ignore it. It might be some other kind of change
 	// (refs/meta/config or Gerrit-internal), but it is not an error.
@@ -339,32 +364,38 @@ func buildTriggerFromPatchsetCreated(cfg *config) (*buildTrigger, error) {
 // Extract the buildtrigger struct out of the flags passed to besadii
 // when invoked as Gerrit's 'change-merged' hook. This hook is used
 // for triggering HEAD builds after change submission.
-func buildTriggerFromChangeMerged(cfg *config) *buildTrigger {
+func buildTriggerFromChangeMerged(cfg *config) (*buildTrigger, error) {
 	// Information that needs to be returned
 	var trigger buildTrigger
 
 	// Information that is only needed for parsing
-	var targetBranch string
+	var targetBranch, submitter string
 
 	flag.StringVar(&trigger.project, "project", "", "Gerrit project")
 	flag.StringVar(&trigger.commit, "commit", "", "Commit hash")
-	flag.StringVar(&trigger.owner, "change-owner", "", "Change owner")
+	flag.StringVar(&submitter, "submitter", "", "Submitter email & username")
 	flag.StringVar(&targetBranch, "branch", "", "CL target branch")
 
 	// Ignore extra flags passed by change-merged
-	ignoreFlags([]string{"change", "topic", "change-url", "submitter", "submitter-username", "newrev", "change-owner-username"})
+	ignoreFlags([]string{"change", "topic", "change-url", "submitter-username", "newrev", "change-owner", "change-owner-username"})
 
 	flag.Parse()
 
+	// Parse username & email
+	err := extractChangeUploader(submitter, &trigger)
+	if err != nil {
+		return nil, err
+	}
+
 	// If the patchset is not for the HEAD branch of the monorepo, then
 	// we can ignore it.
 	if trigger.project != cfg.Repository || targetBranch != cfg.Branch {
-		return nil
+		return nil, nil
 	}
 
 	trigger.ref = "refs/heads/" + targetBranch
 
-	return &trigger
+	return &trigger, nil
 }
 
 func gerritHookMain(cfg *config, log *syslog.Writer, trigger *buildTrigger) {
@@ -458,7 +489,11 @@ func main() {
 		}
 		gerritHookMain(cfg, log, trigger)
 	} else if bin == "change-merged" {
-		trigger := buildTriggerFromChangeMerged(cfg)
+		trigger, err := buildTriggerFromChangeMerged(cfg)
+		if err != nil {
+			log.Crit("failed to parse 'change-merged' invocation from args")
+			os.Exit(1)
+		}
 		gerritHookMain(cfg, log, trigger)
 	} else if bin == "post-command" {
 		postCommandMain(cfg)