[#579] cmd/node: Add grpc section to config

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

cmd/neofs-node/config/grpc/config.go

@@ -0,0 +1,76 @@
+package grpcconfig
+
+import (
+	"errors"
+
+	"github.com/nspcc-dev/neofs-node/cmd/neofs-node/config"
+)
+
+const (
+	subsection    = "grpc"
+	tlsSubsection = "tls"
+)
+
+var (
+	errEndpointNotSet = errors.New("empty/not set endpoint, see `grpc.endpoint` section")
+	errTLSKeyNotSet   = errors.New("empty/not set TLS key file path, see `grpc.tls.key` section")
+	errTLSCertNotSet  = errors.New("empty/not set TLS certificate file path, see `grpc.tls.certificate` section")
+)
+
+// TLSConfig is a wrapper over "tls" config section which provides access
+// to TLS configuration of gRPC connection.
+type TLSConfig struct {
+	cfg *config.Config
+}
+
+// Endpoint returns value of "endpoint" config parameter
+// from "grpc" section.
+//
+// Panics if value is not a non-empty string.
+func Endpoint(c *config.Config) string {
+	v := config.StringSafe(c.Sub(subsection), "endpoint")
+	if v == "" {
+		panic(errEndpointNotSet)
+	}
+
+	return v
+}
+
+// TLS returns structure that provides access to "tls" subsection of
+// "grpc" section.
+func TLS(c *config.Config) TLSConfig {
+	return TLSConfig{
+		cfg: c.Sub(subsection).Sub(tlsSubsection),
+	}
+}
+
+// Enabled returns value of "enabled" config parameter.
+//
+// Returns false if value is not set.
+func (tls TLSConfig) Enabled() bool {
+	return config.BoolSafe(tls.cfg, "enabled")
+}
+
+// KeyFile returns value of "key" config parameter.
+//
+// Panics if value is not a non-empty string.
+func (tls TLSConfig) KeyFile() string {
+	v := config.StringSafe(tls.cfg, "key")
+	if v == "" {
+		panic(errTLSKeyNotSet)
+	}
+
+	return v
+}
+
+// CertificateFile returns value of "certificate" config parameter.
+//
+// Panics if value is not a non-empty string.
+func (tls TLSConfig) CertificateFile() string {
+	v := config.StringSafe(tls.cfg, "certificate")
+	if v == "" {
+		panic(errTLSCertNotSet)
+	}
+
+	return v
+}