Add logger constructor and replace graceful context

Signed-off-by: Evgeniy Kulikov <kim@nspcc.ru>

cmd/gate/main.go

@@ -1,10 +1,47 @@
 package main
 
+import (
+	"github.com/nspcc-dev/cdn-neofs-sdk/grace"
+	"github.com/nspcc-dev/cdn-neofs-sdk/logger"
+	"github.com/spf13/viper"
+	"go.uber.org/zap"
+)
+
+func newLogger(v *viper.Viper) *zap.Logger {
+	options := []logger.Option{
+		logger.WithLevel(v.GetString("logger.level")),
+		logger.WithTraceLevel(v.GetString("logger.trace_level")),
+
+		logger.WithFormat(v.GetString("logger.format")),
+
+		logger.WithSamplingInitial(v.GetInt("logger.sampling.initial")),
+		logger.WithSamplingThereafter(v.GetInt("logger.sampling.thereafter")),
+
+		logger.WithAppName(v.GetString("app_name")),
+		logger.WithAppVersion(v.GetString("app_version")),
+	}
+
+	if v.GetBool("logger.no_caller") {
+		options = append(options, logger.WithoutCaller())
+	}
+
+	if v.GetBool("logger.no_disclaimer") {
+		options = append(options, logger.WithoutDisclaimer())
+	}
+
+	l, err := logger.New(options...)
+	if err != nil {
+		panic(err)
+	}
+
+	return l
+}
+
 func main() {
 	var (
 		v = newSettings()
 		l = newLogger(v)
-		g = newGracefulContext(l)
+		g = grace.Context(l)
 		a = newApp(g, l, v)
 	)