cmd/watchflakes: only open issues bots that have been dead for 24-hours

This change adds a 24-hour delay before an issue is created for a bot
confirmed as dead. Bot maintainers have commented that there should be
some grace period before an issue is created.

Fixes golang/go#72857

Change-Id: I8372291aa2a713183052e66734d446f053472300
Reviewed-on: https://go-review.googlesource.com/c/build/+/659236
Reviewed-by: Dmitri Shuralyov <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Auto-Submit: Carlos Amedee <[email protected]>

Author: cagedmantis

cmd/watchflakes/luci.go

@@ -152,6 +152,7 @@ type Bot struct {
 	Goarch      string
 	Dead        bool
 	Quarantined bool
+	LastSeen    time.Time
 }
 
 // ListCommits fetches the list of commits from Gerrit.
@@ -733,7 +734,13 @@ nextCursor:
 				fmt.Printf("failed to determine platform for %s: %s\n", bot.GetBotId(), err)
 				continue
 			}
-			brokenBots = append(brokenBots, Bot{ID: bot.BotId, Dead: bot.IsDead, Quarantined: bot.Quarantined, Goos: goos, Goarch: goarch})
+			brokenBots = append(brokenBots, Bot{
+				ID:          bot.BotId,
+				Dead:        bot.IsDead,
+				Quarantined: bot.Quarantined,
+				Goos:        goos,
+				Goarch:      goarch,
+				LastSeen:    bot.GetLastSeenTs().AsTime()})
 		}
 	}
 	if resp.GetCursor() != "" {

cmd/watchflakes/main.go

@@ -356,8 +356,18 @@ func reportBrokenBots(ctx context.Context, c *LUCIClient) {
 	if err != nil {
 		log.Printf("failed to query for platform owners: %s", err)
 	}
+
+	// lastSeenThreshold is the minimum amount of time a dead bot has not been
+	// seen in before an issue is created for it.
+	lastSeenThreshold := 24 * time.Hour
+
 	// for each broken bot, is there an existing open issue?
 	for _, bot := range brokenBots {
+		// Do not open to an issue when a dead bot has not been dead for at least the lastSeenThreshold amount.
+		if bot.Dead && bot.LastSeen.After(time.Now().Add(-lastSeenThreshold)) {
+			fmt.Printf("broken bot %q has not been dead for %s. Skipping issue creation/updates.", bot.ID, lastSeenThreshold.String())
+			continue
+		}
 		if issueID, ok := botIssues[bot.ID]; ok {
 			fmt.Printf("issue #%d found for broken bot %s\n", issueID, bot.ID)
 			continue