Remote Alertmanager: Configure SMTP From address (#104925)

* Remote Alertmanager: Configure SMTP From address

* include smtp from address in config comparison

* updte tests

* trigger build

* make linter happy

* trigger build

* fix test

pkg/services/ngalert/ngalert.go

@@ -213,6 +213,7 @@ func (ng *AlertNG) init() error {
 						PromoteConfig:     true,
 						SyncInterval:      ng.Cfg.UnifiedAlerting.RemoteAlertmanager.SyncInterval,
 						ExternalURL:       ng.Cfg.AppURL,
+						SmtpFrom:          ng.Cfg.Smtp.FromAddress,
 						StaticHeaders:     ng.Cfg.Smtp.StaticHeaders,
 					}
 					remoteAM, err := createRemoteAlertmanager(ctx, cfg, ng.KVStore, ng.SecretsService.Decrypt, autogenFn, m, ng.tracer)
@@ -249,6 +250,7 @@ func (ng *AlertNG) init() error {
 						TenantID:          ng.Cfg.UnifiedAlerting.RemoteAlertmanager.TenantID,
 						URL:               ng.Cfg.UnifiedAlerting.RemoteAlertmanager.URL,
 						ExternalURL:       ng.Cfg.AppURL,
+						SmtpFrom:          ng.Cfg.Smtp.FromAddress,
 						StaticHeaders:     ng.Cfg.Smtp.StaticHeaders,
 					}
 					remoteAM, err := createRemoteAlertmanager(ctx, cfg, ng.KVStore, ng.SecretsService.Decrypt, autogenFn, m, ng.tracer)
@@ -287,6 +289,7 @@ func (ng *AlertNG) init() error {
 						URL:               ng.Cfg.UnifiedAlerting.RemoteAlertmanager.URL,
 						SyncInterval:      ng.Cfg.UnifiedAlerting.RemoteAlertmanager.SyncInterval,
 						ExternalURL:       ng.Cfg.AppURL,
+						SmtpFrom:          ng.Cfg.Smtp.FromAddress,
 						StaticHeaders:     ng.Cfg.Smtp.StaticHeaders,
 					}
 					remoteAM, err := createRemoteAlertmanager(ctx, cfg, ng.KVStore, ng.SecretsService.Decrypt, autogenFn, m, ng.tracer)

pkg/services/ngalert/remote/alertmanager.go

@@ -60,6 +60,7 @@ type Alertmanager struct {
 	orgID             int64
 	ready             bool
 	sender            *sender.ExternalAlertmanager
+	smtpFrom          string
 	state             stateStore
 	tenantID          string
 	url               string
@@ -86,7 +87,8 @@ type AlertmanagerConfig struct {
 	// The same flag is used for promoting state.
 	PromoteConfig bool
 
-	// StaticHeaders are used in email notifications sent by the remote Alertmanager.
+	// SmtpFrom and StaticHeaders are used in email notifications sent by the remote Alertmanager.
+	SmtpFrom      string
 	StaticHeaders map[string]string
 
 	// SyncInterval determines how often we should attempt to synchronize configuration.
@@ -126,6 +128,7 @@ func NewAlertmanager(ctx context.Context, cfg AlertmanagerConfig, store stateSto
 		URL:           u,
 		PromoteConfig: cfg.PromoteConfig,
 		ExternalURL:   cfg.ExternalURL,
+		SmtpFrom:      cfg.SmtpFrom,
 		StaticHeaders: cfg.StaticHeaders,
 	}
 	mc, err := remoteClient.New(mcCfg, metrics, tracer)
@@ -193,6 +196,7 @@ func NewAlertmanager(ctx context.Context, cfg AlertmanagerConfig, store stateSto
 		metrics:           metrics,
 		mimirClient:       mc,
 		orgID:             cfg.OrgID,
+		smtpFrom:          cfg.SmtpFrom,
 		state:             store,
 		sender:            s,
 		syncInterval:      cfg.SyncInterval,
@@ -670,6 +674,11 @@ func (am *Alertmanager) shouldSendConfig(ctx context.Context, hash [16]byte) boo
 		return true
 	}
 
+	if rc.SmtpFrom != am.smtpFrom {
+		am.log.Debug("SMTP 'from' address is different, sending the configuration to the remote Alertmanager", "remote", rc.SmtpFrom, "local", am.smtpFrom)
+		return true
+	}
+
 	rawRemote, err := json.Marshal(rc.GrafanaAlertmanagerConfig)
 	if err != nil {
 		am.log.Error("Unable to marshal the remote Alertmanager configuration for comparison", "err", err)

pkg/services/ngalert/remote/alertmanager_test.go

@@ -137,20 +137,24 @@ func TestApplyConfig(t *testing.T) {
 	})
 
 	var configSent client.UserGrafanaConfig
-	var lastConfigSync, lastStateSync time.Time
+	var configSyncs, stateSyncs int
 	okHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		require.Equal(t, tenantID, r.Header.Get(client.MimirTenantHeader))
 		require.Equal(t, "true", r.Header.Get(client.RemoteAlertmanagerHeader))
+		var res = map[string]any{"status": "success"}
+
 		if r.Method == http.MethodPost {
 			if strings.Contains(r.URL.Path, "/config") {
 				require.NoError(t, json.NewDecoder(r.Body).Decode(&configSent))
-				lastConfigSync = time.Now()
+				configSyncs++
 			} else {
-				lastStateSync = time.Now()
+				stateSyncs++
 			}
+		} else {
+			res["data"] = &configSent
 		}
 		w.Header().Add("content-type", "application/json")
-		require.NoError(t, json.NewEncoder(w).Encode(map[string]string{"status": "success"}))
+		require.NoError(t, json.NewEncoder(w).Encode(res))
 	})
 
 	// Encrypt receivers to save secrets in the database.
@@ -178,6 +182,7 @@ func TestApplyConfig(t *testing.T) {
 		PromoteConfig: true,
 		SyncInterval:  1 * time.Hour,
 		ExternalURL:   "https://test.grafana.com",
+		SmtpFrom:      "test-instance@grafana.net",
 		StaticHeaders: map[string]string{"Header-1": "Value-1", "Header-2": "Value-2"},
 	}
 
@@ -197,11 +202,15 @@ func TestApplyConfig(t *testing.T) {
 	}
 	require.Error(t, am.ApplyConfig(ctx, config))
 	require.False(t, am.Ready())
+	require.Equal(t, 0, stateSyncs)
+	require.Equal(t, 0, configSyncs)
 
 	// A 200 status code response should make the check succeed.
 	server.Config.Handler = okHandler
 	require.NoError(t, am.ApplyConfig(ctx, config))
 	require.True(t, am.Ready())
+	require.Equal(t, 1, stateSyncs)
+	require.Equal(t, 1, configSyncs)
 
 	// The sent configuration should be unencrypted and promoted.
 	amCfg, err := json.Marshal(configSent.GrafanaAlertmanagerConfig)
@@ -209,28 +218,46 @@ func TestApplyConfig(t *testing.T) {
 	require.JSONEq(t, testGrafanaConfigWithSecret, string(amCfg))
 	require.True(t, configSent.Promoted)
 
-	// Grafana's URL and static headers should be sent alongside the configuration.
+	// Grafana's URL, email "from" address, and static headers should be sent alongside the configuration.
 	require.Equal(t, cfg.ExternalURL, configSent.ExternalURL)
+	require.Equal(t, cfg.SmtpFrom, configSent.SmtpFrom)
 	require.Equal(t, cfg.StaticHeaders, configSent.StaticHeaders)
 
 	// If we already got a 200 status code response and the sync interval hasn't elapsed,
 	// we shouldn't send the state/configuration again.
-	expStateSync := lastStateSync
-	expConfigSync := lastConfigSync
 	require.NoError(t, am.ApplyConfig(ctx, config))
-	require.Equal(t, expStateSync, lastStateSync)
-	require.Equal(t, expConfigSync, lastConfigSync)
+	require.Equal(t, 1, stateSyncs)
+	require.Equal(t, 1, configSyncs)
 
-	// Changing the sync interval and calling ApplyConfig again
+	// Changing the sync interval and calling ApplyConfig again with a new config
 	// should result in us sending the configuration but not the state.
 	am.syncInterval = 0
+	config = &ngmodels.AlertConfiguration{
+		AlertmanagerConfiguration: string(testGrafanaConfig),
+	}
+	require.NoError(t, am.ApplyConfig(ctx, config))
+	require.Equal(t, 2, configSyncs)
+	require.Equal(t, 1, stateSyncs)
+
+	// After a restart, the Alertmanager shouldn't send the configuration if it has not changed.
+	am, err = NewAlertmanager(cfg, fstore, secretsService.Decrypt, NoopAutogenFn, m, tracing.InitializeTracerForTest())
+	require.NoError(t, err)
+	require.NoError(t, am.ApplyConfig(ctx, config))
+	require.Equal(t, 2, configSyncs)
+
+	// Changing the "from" address should result in the configuration being updated.
+	cfg.SmtpFrom = "new-address@test.com"
+	am, err = NewAlertmanager(cfg, fstore, secretsService.Decrypt, NoopAutogenFn, m, tracing.InitializeTracerForTest())
+	require.NoError(t, err)
 	require.NoError(t, am.ApplyConfig(ctx, config))
-	require.Equal(t, lastStateSync, expStateSync)
-	require.Greater(t, lastConfigSync, expConfigSync)
+	require.Equal(t, 3, configSyncs)
+	require.Equal(t, am.smtpFrom, configSent.SmtpFrom)
 
 	// Failing to add the auto-generated routes should result in an error.
-	am.autogenFn = errAutogenFn
+	am, err = NewAlertmanager(cfg, fstore, secretsService.Decrypt, errAutogenFn, m, tracing.InitializeTracerForTest())
+	require.NoError(t, err)
 	require.ErrorIs(t, am.ApplyConfig(ctx, config), errTest)
+	require.Equal(t, 3, configSyncs)
 }
 
 func TestCompareAndSendConfiguration(t *testing.T) {
@@ -315,9 +342,7 @@ func TestCompareAndSendConfiguration(t *testing.T) {
 			"error from autogen function",
 			strings.Replace(testGrafanaConfigWithSecret, `"password":"test"`, fmt.Sprintf("%q:%q", "password", base64.StdEncoding.EncodeToString(testValue)), 1),
 			errAutogenFn,
-			&client.UserGrafanaConfig{
-				GrafanaAlertmanagerConfig: cfgWithSecret,
-			},
+			nil,
 			errTest.Error(),
 		},
 		{

pkg/services/ngalert/remote/client/alertmanager_configuration.go

@@ -22,6 +22,7 @@ type UserGrafanaConfig struct {
 	Default                   bool                          `json:"default"`
 	Promoted                  bool                          `json:"promoted"`
 	ExternalURL               string                        `json:"external_url"`
+	SmtpFrom                  string                        `json:"smtp_from"`
 	StaticHeaders             map[string]string             `json:"static_headers"`
 }
 
@@ -56,6 +57,7 @@ func (mc *Mimir) CreateGrafanaAlertmanagerConfig(ctx context.Context, cfg *apimo
 		Default:                   isDefault,
 		Promoted:                  mc.promoteConfig,
 		ExternalURL:               mc.externalURL,
+		SmtpFrom:                  mc.smtpFrom,
 		StaticHeaders:             mc.staticHeaders,
 	})
 	if err != nil {

pkg/services/ngalert/remote/client/mimir.go

@@ -48,6 +48,7 @@ type Mimir struct {
 	metrics       *metrics.RemoteAlertmanager
 	promoteConfig bool
 	externalURL   string
+	smtpFrom      string
 	staticHeaders map[string]string
 }
 
@@ -59,6 +60,7 @@ type Config struct {
 	Logger        log.Logger
 	PromoteConfig bool
 	ExternalURL   string
+	SmtpFrom      string
 	StaticHeaders map[string]string
 }
 
@@ -103,6 +105,7 @@ func New(cfg *Config, metrics *metrics.RemoteAlertmanager, tracer tracing.Tracer
 		metrics:       metrics,
 		promoteConfig: cfg.PromoteConfig,
 		externalURL:   cfg.ExternalURL,
+		smtpFrom:      cfg.SmtpFrom,
 		staticHeaders: cfg.StaticHeaders,
 	}, nil
 }