Alerting: Send configuration and state to the remote Alertmanager on shutdown (#78682)

* Alerting: Send configuration and state to the remote Alertmanager on shutdown

* Alerting: Add a sync interval for ApplyConfig in remote secondary mode

* add routine to sync states and configs

* pass a cancellable context to syncRoutine(), remove tests for ApplyConfig, cache last config in memory

* extract logic to update config and state in the remote Alertmanager

* get latest config from the database

* avoid using separate goroutine for updating state and config

* clean up PR

* refactor, comments, tests

* update tests

* remove canceled context from calls to StopAndWait()

* create context with timeout and send config and state to remote Alertmanager

* update tests

* address code review comments

pkg/services/ngalert/remote/alertmanager.go

@@ -336,8 +336,6 @@ func (am *Alertmanager) TestTemplate(ctx context.Context, c apimodels.TestTempla
 // In the context of a "remote Alertmanager" it is a good heuristic for Grafana is about to shut down or we no longer need you.
 func (am *Alertmanager) StopAndWait() {
 	am.sender.Stop()
-
-	// Upload the configuration and state
 }
 
 func (am *Alertmanager) Ready() bool {

pkg/services/ngalert/remote/forked_alertmanager_test.go

@@ -323,11 +323,41 @@ func TestForkedAlertmanager_ModeRemoteSecondary(t *testing.T) {
 	})
 
 	t.Run("StopAndWait", func(tt *testing.T) {
-		// StopAndWait should be called on both Alertmanagers.
-		internal, remote, forked := genTestAlertmanagers(tt, modeRemoteSecondary)
-		internal.EXPECT().StopAndWait().Once()
-		remote.EXPECT().StopAndWait().Once()
-		forked.StopAndWait()
+		{
+			// StopAndWait should be called in both Alertmanagers.
+			// Methods to sync the Alertmanagers should be called on the remote Alertmanager.
+			internal, remote, forked := genTestAlertmanagers(tt, modeRemoteSecondary)
+			internal.EXPECT().StopAndWait().Once()
+			remote.EXPECT().StopAndWait().Once()
+			remote.EXPECT().CompareAndSendConfiguration(mock.Anything, mock.Anything).Return(nil).Once()
+			remote.EXPECT().CompareAndSendState(mock.Anything).Return(nil).Once()
+			forked.StopAndWait()
+		}
+
+		{
+			// An error in the remote Alertmanager should't be a problem.
+			// These errors are caught and logged.
+			internal, remote, forked := genTestAlertmanagers(tt, modeRemoteSecondary)
+			internal.EXPECT().StopAndWait().Once()
+			remote.EXPECT().StopAndWait().Once()
+			remote.EXPECT().CompareAndSendConfiguration(mock.Anything, mock.Anything).Return(expErr).Once()
+			remote.EXPECT().CompareAndSendState(mock.Anything).Return(expErr).Once()
+			forked.StopAndWait()
+		}
+
+		{
+			// An error when retrieving the configuration should cause
+			// CompareAndSendConfiguration not to be called.
+			internal, remote, forked := genTestAlertmanagers(tt, modeRemoteSecondary)
+			secondaryForked, ok := forked.(*RemoteSecondaryForkedAlertmanager)
+			require.True(t, ok)
+			secondaryForked.store = &errConfigStore{}
+
+			internal.EXPECT().StopAndWait().Once()
+			remote.EXPECT().StopAndWait().Once()
+			remote.EXPECT().CompareAndSendState(mock.Anything).Return(expErr).Once()
+			forked.StopAndWait()
+		}
 	})
 
 	t.Run("Ready", func(tt *testing.T) {
@@ -583,9 +613,14 @@ func genTestAlertmanagersWithSyncInterval(t *testing.T, mode int, syncInterval t
 	remote := remote_alertmanager_mock.NewRemoteAlertmanagerMock(t)
 
 	if mode == modeRemoteSecondary {
+		configs := map[int64]*models.AlertConfiguration{
+			1: {},
+		}
 		cfg := RemoteSecondaryConfig{
 			Logger:       log.NewNopLogger(),
 			SyncInterval: syncInterval,
+			OrgID:        1,
+			Store:        notifier.NewFakeConfigStore(t, configs),
 		}
 		forked, err := NewRemoteSecondaryForkedAlertmanager(cfg, internal, remote)
 		require.NoError(t, err)
@@ -593,3 +628,10 @@ func genTestAlertmanagersWithSyncInterval(t *testing.T, mode int, syncInterval t
 	}
 	return internal, remote, NewRemotePrimaryForkedAlertmanager(internal, remote)
 }
+
+// errConfigStore returns an error when a method is called.
+type errConfigStore struct{}
+
+func (s *errConfigStore) GetLatestAlertmanagerConfiguration(context.Context, int64) (*models.AlertConfiguration, error) {
+	return nil, errors.New("test error")
+}

pkg/services/ngalert/remote/remote_secondary_forked_alertmanager.go

@@ -12,6 +12,10 @@ import (
 	"github.com/grafana/grafana/pkg/services/ngalert/notifier"
 )
 
+type configStore interface {
+	GetLatestAlertmanagerConfiguration(ctx context.Context, orgID int64) (*models.AlertConfiguration, error)
+}
+
 //go:generate mockery --name remoteAlertmanager --structname RemoteAlertmanagerMock --with-expecter --output mock --outpkg alertmanager_mock
 type remoteAlertmanager interface {
 	notifier.Alertmanager
@@ -20,7 +24,9 @@ type remoteAlertmanager interface {
 }
 
 type RemoteSecondaryForkedAlertmanager struct {
-	log log.Logger
+	log   log.Logger
+	orgID int64
+	store configStore
 
 	internal notifier.Alertmanager
 	remote   remoteAlertmanager
@@ -30,10 +36,13 @@ type RemoteSecondaryForkedAlertmanager struct {
 }
 
 type RemoteSecondaryConfig struct {
+	Logger log.Logger
+	OrgID  int64
+	Store  configStore
+
 	// SyncInterval determines how often we should attempt to synchronize
 	// state and configuration on the external Alertmanager.
 	SyncInterval time.Duration
-	Logger       log.Logger
 }
 
 func (c *RemoteSecondaryConfig) Validate() error {
@@ -49,6 +58,8 @@ func NewRemoteSecondaryForkedAlertmanager(cfg RemoteSecondaryConfig, internal no
 	}
 	return &RemoteSecondaryForkedAlertmanager{
 		log:          cfg.Logger,
+		orgID:        cfg.OrgID,
+		store:        cfg.Store,
 		internal:     internal,
 		remote:       remote,
 		syncInterval: cfg.SyncInterval,
@@ -160,9 +171,26 @@ func (fam *RemoteSecondaryForkedAlertmanager) CleanUp() {
 }
 
 func (fam *RemoteSecondaryForkedAlertmanager) StopAndWait() {
+	// Stop the internal Alertmanager.
 	fam.internal.StopAndWait()
+	// Stop our alert senders.
 	fam.remote.StopAndWait()
-	// TODO: send config and state on shutdown.
+
+	// Send config and state to the remote Alertmanager.
+	// Using context.TODO() here as we think we want to allow this operation to finish regardless of time.
+	ctx := context.TODO()
+	if err := fam.remote.CompareAndSendState(ctx); err != nil {
+		fam.log.Error("Error sending state to the remote Alertmanager while stopping", "err", err)
+	}
+
+	config, err := fam.store.GetLatestAlertmanagerConfiguration(ctx, fam.orgID)
+	if err != nil {
+		fam.log.Error("Error getting latest Alertmanager configuration while stopping", "err", err)
+		return
+	}
+	if err := fam.remote.CompareAndSendConfiguration(ctx, config); err != nil {
+		fam.log.Error("Error sending configuration to the remote Alertmanager while stopping", "err", err)
+	}
 }
 
 func (fam *RemoteSecondaryForkedAlertmanager) Ready() bool {