From 32d92d4e3f4739260fd9b48f0a91d9d7fac9130a Mon Sep 17 00:00:00 2001
From: JamesJJ <jj@fcg.fyi>
Date: Thu, 15 Apr 2021 21:00:21 +0800
Subject: [PATCH] Env SUPPRESS_UNKNOWN_TO_OK (bool) to eliminate non-actionable
 alerts

---
 function/main.go | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/function/main.go b/function/main.go
index a98105a..7f04a84 100644
--- a/function/main.go
+++ b/function/main.go
@@ -10,9 +10,16 @@ import (
 	"log"
 	"net/http"
 	"os"
+	"strconv"
 	"time"
 )
 
+var (
+	SuppressableAlertsStateFromTo = map[string]string{
+		"INSUFFICIENT_DATA": "OK",
+	}
+)
+
 func handleRequest(request events.SNSEvent) error {
 
 	var cloudwatchAlarm events.CloudWatchAlarmSNSPayload
@@ -22,6 +29,18 @@ func handleRequest(request events.SNSEvent) error {
 		return nil // Non-retryable error
 	}
 
+	if suppress, err := strconv.ParseBool(os.Getenv("SUPPRESS_UNKNOWN_TO_OK")); err == nil && suppress {
+		if SuppressableAlertsStateFromTo[cloudwatchAlarm.OldStateValue] == cloudwatchAlarm.NewStateValue {
+			log.Printf(
+				"Alarm suppressed for %s --> %s \"%s\"",
+				cloudwatchAlarm.OldStateValue,
+				cloudwatchAlarm.NewStateValue,
+				cloudwatchAlarm.AlarmName,
+			)
+			return nil
+		}
+	}
+
 	log.Printf(
 		"Alarm: %s --> %s \"%s\"",
 		cloudwatchAlarm.OldStateValue,