From e15e40fbd3e017b35d9572f277a83cbbda020680 Mon Sep 17 00:00:00 2001
From: Santiago <santiagohernandez.1997@gmail.com>
Date: Mon, 10 Jun 2024 13:51:11 +0200
Subject: [PATCH] Alerting: Skip setting up clustering in remote primary/only
 modes (#88968)

* Alerting: Skip setting up clustering in remote primary mode

* Update pkg/services/ngalert/notifier/multiorg_alertmanager.go

Co-authored-by: Steve Simpson <steve.simpson@grafana.com>

---------

Co-authored-by: Steve Simpson <steve.simpson@grafana.com>
---
 pkg/services/ngalert/ngalert.go                        | 2 ++
 pkg/services/ngalert/notifier/multiorg_alertmanager.go | 8 ++++++--
 pkg/setting/setting_unified_alerting.go                | 1 +
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/pkg/services/ngalert/ngalert.go b/pkg/services/ngalert/ngalert.go
index 5e7640bf535..1c4003182ce 100644
--- a/pkg/services/ngalert/ngalert.go
+++ b/pkg/services/ngalert/ngalert.go
@@ -177,6 +177,7 @@ func (ng *AlertNG) init() error {
 			ng.Log.Debug("Starting Grafana with remote only mode enabled")
 			m := ng.Metrics.GetRemoteAlertmanagerMetrics()
 			m.Info.WithLabelValues(metrics.ModeRemoteOnly).Set(1)
+			ng.Cfg.UnifiedAlerting.SkipClustering = true
 
 			// This function will be used by the MOA to create new Alertmanagers.
 			override := notifier.WithAlertmanagerOverride(func(_ notifier.OrgAlertmanagerFactory) notifier.OrgAlertmanagerFactory {
@@ -203,6 +204,7 @@ func (ng *AlertNG) init() error {
 
 		case remotePrimary:
 			ng.Log.Warn("Only remote secondary mode is supported at the moment, falling back to remote secondary")
+			// TODO: Skip setting up clustering with ng.Cfg.UnifiedAlerting.SkipClustering = true
 			fallthrough
 
 		case remoteSecondary:
diff --git a/pkg/services/ngalert/notifier/multiorg_alertmanager.go b/pkg/services/ngalert/notifier/multiorg_alertmanager.go
index 26ee2f13e12..4f70a3b57d9 100644
--- a/pkg/services/ngalert/notifier/multiorg_alertmanager.go
+++ b/pkg/services/ngalert/notifier/multiorg_alertmanager.go
@@ -142,8 +142,12 @@ func NewMultiOrgAlertmanager(
 		peer:           &NilPeer{},
 	}
 
-	if err := moa.setupClustering(cfg); err != nil {
-		return nil, err
+	if cfg.UnifiedAlerting.SkipClustering {
+		l.Info("Skipping setting up clustering for MOA")
+	} else {
+		if err := moa.setupClustering(cfg); err != nil {
+			return nil, err
+		}
 	}
 
 	// Set up the default per tenant Alertmanager factory.
diff --git a/pkg/setting/setting_unified_alerting.go b/pkg/setting/setting_unified_alerting.go
index d6f674979e3..228fb049dc1 100644
--- a/pkg/setting/setting_unified_alerting.go
+++ b/pkg/setting/setting_unified_alerting.go
@@ -98,6 +98,7 @@ type UnifiedAlertingSettings struct {
 	DefaultRuleEvaluationInterval time.Duration
 	Screenshots                   UnifiedAlertingScreenshotSettings
 	ReservedLabels                UnifiedAlertingReservedLabelSettings
+	SkipClustering                bool
 	StateHistory                  UnifiedAlertingStateHistorySettings
 	RemoteAlertmanager            RemoteAlertmanagerSettings
 	// MaxStateSaveConcurrency controls the number of goroutines (per rule) that can save alert state in parallel.