From bb90fe2c69ceb85caaca0524cc2bf8d986a17216 Mon Sep 17 00:00:00 2001
From: diphantxm <diphantxm@yandex-team.ru>
Date: Mon, 6 May 2024 12:28:59 +0300
Subject: [PATCH] add systemd notify

---
 coordinator/app/app.go    | 27 +++++++++++++++++++++++++++
 pkg/config/coordinator.go | 18 ++++++++++--------
 2 files changed, 37 insertions(+), 8 deletions(-)

diff --git a/coordinator/app/app.go b/coordinator/app/app.go
index f56ce3e42..ee81e687e 100644
--- a/coordinator/app/app.go
+++ b/coordinator/app/app.go
@@ -7,6 +7,7 @@ import (
 	"os"
 	"path"
 	"sync"
+	"time"
 
 	"github.com/pg-sharding/spqr/pkg/spqrlog"
 	"github.com/pg-sharding/spqr/router/port"
@@ -18,6 +19,7 @@ import (
 	"github.com/pg-sharding/spqr/coordinator/provider"
 	"github.com/pg-sharding/spqr/pkg/config"
 	protos "github.com/pg-sharding/spqr/pkg/protos"
+	sdnotifier "github.com/pg-sharding/spqr/router/sdnotifier"
 
 	"golang.org/x/sync/semaphore"
 )
@@ -43,6 +45,20 @@ func (app *App) Run(withPsql bool) error {
 
 	app.coordinator.RunCoordinator(context.TODO(), !withPsql)
 
+	var notifier *sdnotifier.Notifier
+	if config.CoordinatorConfig().UseSystemdNotifier {
+		// systemd notifier
+		var err error
+		notifier, err = sdnotifier.NewNotifier(os.Getenv("NOTIFY_SOCKET"), config.CoordinatorConfig().SystemdNotifierDebug)
+		if err != nil {
+			return err
+		}
+
+		if err := notifier.Ready(); err != nil {
+			return fmt.Errorf("could not send ready msg: %s", err)
+		}
+	}
+
 	wg := &sync.WaitGroup{}
 
 	wg.Add(1)
@@ -66,6 +82,17 @@ func (app *App) Run(withPsql bool) error {
 		}
 	}(wg)
 
+	if notifier != nil {
+		go func() {
+			for {
+				if err := notifier.Notify(); err != nil {
+					spqrlog.Zero.Error().Err(err).Msg("error sending systemd notification")
+				}
+				time.Sleep(sdnotifier.Timeout)
+			}
+		}()
+	}
+
 	wg.Wait()
 
 	spqrlog.Zero.Debug().Msg("exit coordinator app")
diff --git a/pkg/config/coordinator.go b/pkg/config/coordinator.go
index 99b79abb5..4a51e58eb 100644
--- a/pkg/config/coordinator.go
+++ b/pkg/config/coordinator.go
@@ -14,14 +14,16 @@ import (
 var cfgCoordinator Coordinator
 
 type Coordinator struct {
-	LogLevel        string     `json:"log_level" toml:"log_level" yaml:"log_level"`
-	QdbAddr         string     `json:"qdb_addr" toml:"qdb_addr" yaml:"qdb_addr"`
-	CoordinatorPort string     `json:"coordinator_port" toml:"coordinator_port" yaml:"coordinator_port"`
-	GrpcApiPort     string     `json:"grpc_api_port" toml:"grpc_api_port" yaml:"grpc_api_port"`
-	Host            string     `json:"host" toml:"host" yaml:"host"`
-	Auth            *AuthCfg   `json:"auth" toml:"auth" yaml:"auth"`
-	FrontendTLS     *TLSConfig `json:"frontend_tls" yaml:"frontend_tls" toml:"frontend_tls"`
-	ShardDataCfg    string     `json:"shard_data" toml:"shard_data" yaml:"shard_data"`
+	LogLevel             string     `json:"log_level" toml:"log_level" yaml:"log_level"`
+	QdbAddr              string     `json:"qdb_addr" toml:"qdb_addr" yaml:"qdb_addr"`
+	CoordinatorPort      string     `json:"coordinator_port" toml:"coordinator_port" yaml:"coordinator_port"`
+	GrpcApiPort          string     `json:"grpc_api_port" toml:"grpc_api_port" yaml:"grpc_api_port"`
+	Host                 string     `json:"host" toml:"host" yaml:"host"`
+	Auth                 *AuthCfg   `json:"auth" toml:"auth" yaml:"auth"`
+	FrontendTLS          *TLSConfig `json:"frontend_tls" yaml:"frontend_tls" toml:"frontend_tls"`
+	ShardDataCfg         string     `json:"shard_data" toml:"shard_data" yaml:"shard_data"`
+	UseSystemdNotifier   bool       `json:"use_systemd_notifier" toml:"use_systemd_notifier" yaml:"use_systemd_notifier"`
+	SystemdNotifierDebug bool       `json:"systemd_notifier_debug" toml:"systemd_notifier_debug" yaml:"systemd_notifier_debug"`
 }
 
 func LoadCoordinatorCfg(cfgPath string) error {