From 099ceeae501f1e20abfa2adb147d707a2b22817b Mon Sep 17 00:00:00 2001
From: Leonard Lyubich <leonard@nspcc.ru>
Date: Fri, 21 May 2021 20:40:43 +0300
Subject: [PATCH] [#493] node/config: Implement ENV variable key constructor

Add `internal.Env` function which converts path to config value to ENV
variable key.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
---
 cmd/neofs-node/config/internal/env.go      | 14 ++++++++++++++
 cmd/neofs-node/config/internal/env_test.go | 15 +++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100644 cmd/neofs-node/config/internal/env_test.go

diff --git a/cmd/neofs-node/config/internal/env.go b/cmd/neofs-node/config/internal/env.go
index e5174254..43cd8d44 100644
--- a/cmd/neofs-node/config/internal/env.go
+++ b/cmd/neofs-node/config/internal/env.go
@@ -1,8 +1,22 @@
 package internal
 
+import (
+	"strings"
+)
+
 // EnvPrefix is a prefix of ENV variables related
 // to storage node configuration.
 const EnvPrefix = "neofs"
 
 // EnvSeparator is a section separator in ENV variables.
 const EnvSeparator = "_"
+
+// Env returns ENV variable key for particular config parameter.
+func Env(path ...string) string {
+	return strings.ToUpper(
+		strings.Join(
+			append([]string{EnvPrefix}, path...),
+			EnvSeparator,
+		),
+	)
+}
diff --git a/cmd/neofs-node/config/internal/env_test.go b/cmd/neofs-node/config/internal/env_test.go
new file mode 100644
index 00000000..a599ad45
--- /dev/null
+++ b/cmd/neofs-node/config/internal/env_test.go
@@ -0,0 +1,15 @@
+package internal_test
+
+import (
+	"testing"
+
+	"github.com/nspcc-dev/neofs-node/cmd/neofs-node/config/internal"
+	"github.com/stretchr/testify/require"
+)
+
+func TestEnv(t *testing.T) {
+	require.Equal(t,
+		"NEOFS_SECTION_PARAMETER",
+		internal.Env("section", "parameter"),
+	)
+}