[#493] node/config: Implement sections of local object storage

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

cmd/neofs-node/config/engine/shard/config.go

@@ -0,0 +1,60 @@
+package shardconfig
+
+import (
+	"github.com/nspcc-dev/neofs-node/cmd/neofs-node/config"
+	blobstorconfig "github.com/nspcc-dev/neofs-node/cmd/neofs-node/config/engine/shard/blobstor"
+	gcconfig "github.com/nspcc-dev/neofs-node/cmd/neofs-node/config/engine/shard/gc"
+	metabaseconfig "github.com/nspcc-dev/neofs-node/cmd/neofs-node/config/engine/shard/metabase"
+	writecacheconfig "github.com/nspcc-dev/neofs-node/cmd/neofs-node/config/engine/shard/writecache"
+)
+
+// Config is a wrapper over the config section
+// which provides access to Shard configurations.
+type Config config.Config
+
+// From wraps config section into Config.
+func From(c *config.Config) *Config {
+	return (*Config)(c)
+}
+
+// UseWriteCache returns value of "use_write_cache" config parameter.
+//
+// Panics if value is not a valid bool.
+func (x *Config) UseWriteCache() bool {
+	return config.Bool(
+		(*config.Config)(x),
+		"use_write_cache",
+	)
+}
+
+// BlobStor returns "blobstor" subsection as a blobstorconfig.Config.
+func (x *Config) BlobStor() *blobstorconfig.Config {
+	return blobstorconfig.From(
+		(*config.Config)(x).
+			Sub("blobstor"),
+	)
+}
+
+// Metabase returns "metabase" subsection as a metabaseconfig.Config.
+func (x *Config) Metabase() *metabaseconfig.Config {
+	return metabaseconfig.From(
+		(*config.Config)(x).
+			Sub("metabase"),
+	)
+}
+
+// WriteCache returns "writecache" subsection as a writecacheconfig.Config.
+func (x *Config) WriteCache() *writecacheconfig.Config {
+	return writecacheconfig.From(
+		(*config.Config)(x).
+			Sub("writecache"),
+	)
+}
+
+// GC returns "gc" subsection as a gcconfig.Config.
+func (x *Config) GC() *gcconfig.Config {
+	return gcconfig.From(
+		(*config.Config)(x).
+			Sub("gc"),
+	)
+}