[#150] Add dropped logs metric

Signed-off-by: Pavel Pogodaev <p.pogodaev@yadro.com>

cmd/http-gw/app.go

@@ -50,35 +50,38 @@ import (
 
 type (
 	app struct {
-		ctx       context.Context
-		log       *zap.Logger
-		logLevel  zap.AtomicLevel
-		pool      *pool.Pool
-		treePool  *treepool.Pool
-		key       *keys.PrivateKey
-		owner     *user.ID
-		cfg       *viper.Viper
-		webServer *fasthttp.Server
-		webDone   chan struct{}
-		resolver  *resolver.ContainerResolver
-		metrics   *gateMetrics
-		services  []*metrics.Service
-		settings  *appSettings
+		ctx            context.Context
+		log            *zap.Logger
+		logLevel       zap.AtomicLevel
+		pool           *pool.Pool
+		treePool       *treepool.Pool
+		key            *keys.PrivateKey
+		owner          *user.ID
+		cfg            *viper.Viper
+		webServer      *fasthttp.Server
+		webDone        chan struct{}
+		resolver       *resolver.ContainerResolver
+		metrics        *gateMetrics
+		services       []*metrics.Service
+		settings       *appSettings
+		loggerSettings *loggerSettings
 
 		servers       []Server
 		unbindServers []ServerInfo
 		mu            sync.RWMutex
 	}
 
+	loggerSettings struct {
+		mu         sync.RWMutex
+		appMetrics *metrics.GateMetrics
+	}
+
 	// App is an interface for the main gateway function.
 	App interface {
 		Wait()
 		Serve()
 	}
 
-	// Option is an application option.
-	Option func(a *app)
-
 	gateMetrics struct {
 		logger   *zap.Logger
 		provider *metrics.GateMetrics
@@ -119,37 +122,17 @@ type (
 	}
 )
 
-// WithLogger returns Option to set a specific logger.
-func WithLogger(l *zap.Logger, lvl zap.AtomicLevel) Option {
-	return func(a *app) {
-		if l == nil {
-			return
-		}
-		a.log = l
-		a.logLevel = lvl
-	}
-}
+func newApp(ctx context.Context, v *viper.Viper) App {
+	logSettings := &loggerSettings{}
+	log := pickLogger(v, logSettings)
 
-// WithConfig returns Option to use specific Viper configuration.
-func WithConfig(c *viper.Viper) Option {
-	return func(a *app) {
-		if c == nil {
-			return
-		}
-		a.cfg = c
-	}
-}
-
-func newApp(ctx context.Context, opt ...Option) App {
 	a := &app{
-		ctx:       ctx,
-		log:       zap.L(),
-		cfg:       viper.GetViper(),
-		webServer: new(fasthttp.Server),
-		webDone:   make(chan struct{}),
-	}
-	for i := range opt {
-		opt[i](a)
+		ctx:            ctx,
+		log:            log.logger,
+		cfg:            v,
+		loggerSettings: logSettings,
+		webServer:      new(fasthttp.Server),
+		webDone:        make(chan struct{}),
 	}
 
 	a.initAppSettings()
@@ -227,6 +210,22 @@ func (s *appSettings) update(v *viper.Viper, l *zap.Logger) {
 	s.corsMaxAge = corsMaxAge
 }
 
+func (s *loggerSettings) DroppedLogsInc() {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	if s.appMetrics != nil {
+		s.appMetrics.DroppedLogsInc()
+	}
+}
+
+func (s *loggerSettings) setMetrics(appMetrics *metrics.GateMetrics) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	s.appMetrics = appMetrics
+}
+
 func (s *appSettings) DefaultTimestamp() bool {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
@@ -338,6 +337,7 @@ func (a *app) initMetrics() {
 	gateMetricsProvider := metrics.NewGateMetrics(a.pool)
 	a.metrics = newGateMetrics(a.log, gateMetricsProvider, a.cfg.GetBool(cfgPrometheusEnabled))
 	a.metrics.SetHealth(metrics.HealthStatusStarting)
+	a.loggerSettings.setMetrics(a.metrics.provider)
 }
 
 func newGateMetrics(logger *zap.Logger, provider *metrics.GateMetrics, enabled bool) *gateMetrics {