[#552] Add systemd notifications to ir service

Signed-off-by: Ekaterina Lebedeva <ekaterina.lebedeva@yadro.com>

config/example/ir.yaml

@@ -119,3 +119,6 @@ prometheus:
   enabled: true
   address: localhost:9090  # Endpoint for application prometheus metrics; disabled by default
   shutdown_timeout: 30s    # Timeout for metrics HTTP server graceful shutdown
+
+systemdnotify:
+  enabled: true

pkg/innerring/innerring.go

@@ -24,6 +24,7 @@ import (
 	control "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/control/ir"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/precision"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/sdnotify"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/block"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
@@ -73,6 +74,7 @@ type (
 		predefinedValidators  keys.PublicKeys
 		initialEpochTickDelta uint32
 		withoutMainNet        bool
+		sdNotify              bool
 
 		// runtime processors
 		netmapProcessor   *netmap.Processor
@@ -336,6 +338,11 @@ func New(ctx context.Context, log *logger.Logger, cfg *viper.Viper, errChan chan
 		irMetrics: metrics,
 	}
 
+	server.sdNotify, err = server.initSdNotify(cfg)
+	if err != nil {
+		return nil, err
+	}
+
 	server.setHealthStatus(control.HealthStatus_HEALTH_STATUS_UNDEFINED)
 
 	// parse notary support
@@ -404,6 +411,13 @@ func New(ctx context.Context, log *logger.Logger, cfg *viper.Viper, errChan chan
 	return server, nil
 }
 
+func (s *Server) initSdNotify(cfg *viper.Viper) (bool, error) {
+	if cfg.GetBool("systemdnotify.enabled") {
+		return true, sdnotify.InitSocket()
+	}
+	return false, nil
+}
+
 func createListener(ctx context.Context, cli *client.Client, p *chainParams) (event.Listener, error) {
 	var (
 		sub subscriber.Subscriber

pkg/innerring/state.go

@@ -7,6 +7,7 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/innerring/processors/governance"
 	control "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/control/ir"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/sdnotify"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/state"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/spf13/viper"
@@ -154,6 +155,7 @@ func (s *Server) ResetEpochTimer(h uint32) error {
 
 func (s *Server) setHealthStatus(hs control.HealthStatus) {
 	s.healthStatus.Store(int32(hs))
+	s.notifySystemd(hs)
 	if s.irMetrics != nil {
 		s.irMetrics.SetHealth(int32(hs))
 	}
@@ -173,3 +175,21 @@ func initPersistentStateStorage(cfg *viper.Viper) (*state.PersistentStorage, err
 
 	return persistStorage, nil
 }
+
+func (s *Server) notifySystemd(st control.HealthStatus) {
+	if !s.sdNotify {
+		return
+	}
+	var err error
+	switch st {
+	case control.HealthStatus_READY:
+		err = sdnotify.FlagAndStatus(sdnotify.ReadyEnabled)
+	case control.HealthStatus_SHUTTING_DOWN:
+		err = sdnotify.FlagAndStatus(sdnotify.StoppingEnabled)
+	default:
+		err = sdnotify.Status(fmt.Sprintf("%v", st))
+	}
+	if err != nil {
+		s.log.Error(logs.FailedToReportStatusToSystemd, zap.Error(err))
+	}
+}