From 2647330f71713e3a14bc7b3a9dd64bd122fea7a7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Mierzwa?= <l.mierzwa@gmail.com>
Date: Sun, 25 Jun 2017 11:21:55 -0700
Subject: [PATCH] Generate AlertGroup unique fingerprint on the fly

---
 alertmanager/models.go |  8 +-------
 models/alertgroup.go   | 11 +++++++++++
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/alertmanager/models.go b/alertmanager/models.go
index 517a28e86..7788e360e 100644
--- a/alertmanager/models.go
+++ b/alertmanager/models.go
@@ -1,9 +1,7 @@
 package alertmanager
 
 import (
-	"crypto/sha1"
 	"fmt"
-	"io"
 	"sort"
 	"sync"
 	"time"
@@ -13,7 +11,6 @@ import (
 	"github.com/cloudflare/unsee/models"
 	"github.com/cloudflare/unsee/transform"
 	"github.com/cloudflare/unsee/transport"
-	"github.com/cnf/structhash"
 	"github.com/prometheus/client_golang/prometheus"
 
 	log "github.com/Sirupsen/logrus"
@@ -107,10 +104,7 @@ func (am *Alertmanager) pullAlerts(version string) error {
 	uniqueGroups := map[string]models.AlertGroup{}
 	uniqueAlerts := map[string]map[string]models.Alert{}
 	for _, ag := range groups {
-		agIDHasher := sha1.New()
-		io.WriteString(agIDHasher, ag.Receiver)
-		io.WriteString(agIDHasher, fmt.Sprintf("%x", structhash.Sha1(ag.Labels, 1)))
-		agID := fmt.Sprintf("%x", agIDHasher.Sum(nil))
+		agID := ag.LabelsFingerprint()
 		if _, found := uniqueGroups[agID]; !found {
 			uniqueGroups[agID] = models.AlertGroup{
 				Receiver: ag.Receiver,
diff --git a/models/alertgroup.go b/models/alertgroup.go
index 114cdfd9f..b6bfc2e92 100644
--- a/models/alertgroup.go
+++ b/models/alertgroup.go
@@ -4,6 +4,8 @@ import (
 	"crypto/sha1"
 	"fmt"
 	"io"
+
+	"github.com/cnf/structhash"
 )
 
 // AlertList is flat list of UnseeAlert objects
@@ -39,6 +41,15 @@ type AlertGroup struct {
 	StateCount map[string]int    `json:"stateCount"`
 }
 
+// LabelsFingerprint is a checksum of this AlertGroup labels and the receiver
+// it should be unique for each AlertGroup
+func (ag AlertGroup) LabelsFingerprint() string {
+	agIDHasher := sha1.New()
+	io.WriteString(agIDHasher, ag.Receiver)
+	io.WriteString(agIDHasher, fmt.Sprintf("%x", structhash.Sha1(ag.Labels, 1)))
+	return fmt.Sprintf("%x", agIDHasher.Sum(nil))
+}
+
 // ContentFingerprint is a checksum of all alerts in the group
 func (ag AlertGroup) ContentFingerprint() string {
 	h := sha1.New()