From 8efe1856e22df23b6b67a1d69c451c93e5248cbc Mon Sep 17 00:00:00 2001
From: Ganesh Vernekar <15064823+codesome@users.noreply.github.com>
Date: Mon, 12 Jul 2021 18:53:01 +0530
Subject: [PATCH] Alerting: A better and cleaner way to know if Alertmanager is
 initialised (#36659)

Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
---
 pkg/services/ngalert/notifier/alertmanager.go | 20 +++++++++----------
 pkg/services/ngalert/notifier/alerts.go       |  2 +-
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/pkg/services/ngalert/notifier/alertmanager.go b/pkg/services/ngalert/notifier/alertmanager.go
index 241e79a8c6b..a763e9efb8a 100644
--- a/pkg/services/ngalert/notifier/alertmanager.go
+++ b/pkg/services/ngalert/notifier/alertmanager.go
@@ -104,8 +104,6 @@ type Alertmanager struct {
 
 	reloadConfigMtx sync.RWMutex
 	config          []byte
-
-	initialised bool
 }
 
 func New(cfg *setting.Cfg, store store.AlertingStore, m *metrics.Metrics) (*Alertmanager, error) {
@@ -158,6 +156,16 @@ func New(cfg *setting.Cfg, store store.AlertingStore, m *metrics.Metrics) (*Aler
 	return am, nil
 }
 
+func (am *Alertmanager) Ready() bool {
+	// We consider AM as ready only when the config has been
+	// applied at least once successfully. Until then, some objects
+	// can still be nil.
+	am.reloadConfigMtx.RLock()
+	defer am.reloadConfigMtx.RUnlock()
+
+	return len(am.config) > 0
+}
+
 func (am *Alertmanager) Run(ctx context.Context) error {
 	// Make sure dispatcher starts. We can tolerate future reload failures.
 	if err := am.SyncAndApplyConfigFromDatabase(); err != nil {
@@ -272,14 +280,6 @@ func (am *Alertmanager) SyncAndApplyConfigFromDatabase() error {
 // applyConfig applies a new configuration by re-initializing all components using the configuration provided.
 // It is not safe to call concurrently.
 func (am *Alertmanager) applyConfig(cfg *apimodels.PostableUserConfig, rawConfig []byte) (err error) {
-	defer func() {
-		if err == nil {
-			// We consider AM as initialised only when the config has been
-			// applied at least once successfully. Until then, some objects
-			// can still be nil.
-			am.initialised = true
-		}
-	}()
 	// First, let's make sure this config is not already loaded
 	var configChanged bool
 	if rawConfig == nil {
diff --git a/pkg/services/ngalert/notifier/alerts.go b/pkg/services/ngalert/notifier/alerts.go
index 02078db01c3..0bc795d96d8 100644
--- a/pkg/services/ngalert/notifier/alerts.go
+++ b/pkg/services/ngalert/notifier/alerts.go
@@ -28,7 +28,7 @@ func (am *Alertmanager) GetAlerts(active, silenced, inhibited bool, filter []str
 		res = apimodels.GettableAlerts{}
 	)
 
-	if !am.initialised {
+	if !am.Ready() {
 		return res, ErrGetAlertsUnavailable
 	}