From 9e64304499ffa3b28694d0ef62d4e87158886154 Mon Sep 17 00:00:00 2001
From: Alex Vanin <a.vanin@yadro.com>
Date: Mon, 21 Oct 2024 15:51:48 +0300
Subject: [PATCH] [#521] Use handler to register dial events

While frostfs-node uses dial handler to udpate metric
value, gateway starts with simple event logging.

Signed-off-by: Alex Vanin <a.vanin@yadro.com>
---
 cmd/s3-gw/app.go              |  4 ++--
 cmd/s3-gw/app_settings.go     |  3 ++-
 internal/logs/logs.go         |  2 ++
 internal/net/config.go        |  2 ++
 internal/net/event_handler.go | 28 ++++++++++++++++++++++++++++
 5 files changed, 36 insertions(+), 3 deletions(-)
 create mode 100644 internal/net/event_handler.go

diff --git a/cmd/s3-gw/app.go b/cmd/s3-gw/app.go
index 382431b6..3e24acf8 100644
--- a/cmd/s3-gw/app.go
+++ b/cmd/s3-gw/app.go
@@ -658,7 +658,7 @@ func newMaxClients(cfg *viper.Viper) maxClientsConfig {
 }
 
 func getDialerSource(logger *zap.Logger, cfg *viper.Viper) *internalnet.DialerSource {
-	source, err := internalnet.NewDialerSource(fetchMultinetConfig(cfg))
+	source, err := internalnet.NewDialerSource(fetchMultinetConfig(cfg, logger))
 	if err != nil {
 		logger.Fatal(logs.FailedToLoadMultinetConfig, zap.Error(err))
 	}
@@ -892,7 +892,7 @@ func (a *App) updateSettings() {
 		a.settings.logLevel.SetLevel(lvl)
 	}
 
-	if err := a.settings.dialerSource.Update(fetchMultinetConfig(a.cfg)); err != nil {
+	if err := a.settings.dialerSource.Update(fetchMultinetConfig(a.cfg, a.log)); err != nil {
 		a.log.Warn(logs.MultinetConfigWontBeUpdated, zap.Error(err))
 	}
 
diff --git a/cmd/s3-gw/app_settings.go b/cmd/s3-gw/app_settings.go
index 24ceb433..bd7c35cf 100644
--- a/cmd/s3-gw/app_settings.go
+++ b/cmd/s3-gw/app_settings.go
@@ -756,12 +756,13 @@ func fetchVHSNamespaces(v *viper.Viper, log *zap.Logger) map[string]bool {
 	return vhsNamespacesEnabled
 }
 
-func fetchMultinetConfig(v *viper.Viper) (cfg internalnet.Config) {
+func fetchMultinetConfig(v *viper.Viper, logger *zap.Logger) (cfg internalnet.Config) {
 	cfg.Enabled = v.GetBool(cfgMultinetEnabled)
 	cfg.Balancer = v.GetString(cfgMultinetBalancer)
 	cfg.Restrict = v.GetBool(cfgMultinetRestrict)
 	cfg.FallbackDelay = v.GetDuration(cfgMultinetFallbackDelay)
 	cfg.Subnets = make([]internalnet.Subnet, 0, 5)
+	cfg.EventHandler = internalnet.NewLogEventHandler(logger)
 
 	for i := 0; ; i++ {
 		key := cfgMultinetSubnets + "." + strconv.Itoa(i) + "."
diff --git a/internal/logs/logs.go b/internal/logs/logs.go
index a24065a7..3da12556 100644
--- a/internal/logs/logs.go
+++ b/internal/logs/logs.go
@@ -175,4 +175,6 @@ const (
 	CheckCustomAccessKeyIDUniqueness                     = "check custom access key id uniqueness"
 	FailedToLoadMultinetConfig                           = "failed to load multinet config"
 	MultinetConfigWontBeUpdated                          = "multinet config won't be updated"
+	MultinetDialSuccess                                  = "multinet dial successful"
+	MultinetDialFail                                     = "multinet dial failed"
 )
diff --git a/internal/net/config.go b/internal/net/config.go
index 6a047982..b40e003f 100644
--- a/internal/net/config.go
+++ b/internal/net/config.go
@@ -23,6 +23,7 @@ type Config struct {
 	Balancer      string
 	Restrict      bool
 	FallbackDelay time.Duration
+	EventHandler  multinet.EventHandler
 }
 
 func (c Config) toMultinetConfig() (multinet.Config, error) {
@@ -52,6 +53,7 @@ func (c Config) toMultinetConfig() (multinet.Config, error) {
 		Restrict:      c.Restrict,
 		FallbackDelay: c.FallbackDelay,
 		Dialer:        newDefaultDialer(),
+		EventHandler:  c.EventHandler,
 	}, nil
 }
 
diff --git a/internal/net/event_handler.go b/internal/net/event_handler.go
new file mode 100644
index 00000000..866fdd0c
--- /dev/null
+++ b/internal/net/event_handler.go
@@ -0,0 +1,28 @@
+package net
+
+import (
+	"net"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/logs"
+	"go.uber.org/zap"
+)
+
+type LogEventHandler struct {
+	logger *zap.Logger
+}
+
+func (l LogEventHandler) DialPerformed(sourceIP net.Addr, _, address string, err error) {
+	sourceIPString := "undefined"
+	if sourceIP != nil {
+		sourceIPString = sourceIP.Network() + "://" + sourceIP.String()
+	}
+	if err == nil {
+		l.logger.Debug(logs.MultinetDialSuccess, zap.String("source", sourceIPString), zap.String("destination", address))
+	} else {
+		l.logger.Debug(logs.MultinetDialFail, zap.String("source", sourceIPString), zap.String("destination", address), zap.Error(err))
+	}
+}
+
+func NewLogEventHandler(logger *zap.Logger) LogEventHandler {
+	return LogEventHandler{logger: logger}
+}