cleanup: move pkg/ to internal/

The internal/ directory in Go has a special meaning, and indicates that
those packages are not meant for external consumption. Ceph-CSI does
provide public APIs for other projects to consume. There is no plan to
keep the API of the internally used packages stable.

Closes: #903
Signed-off-by: Niels de Vos <ndevos@redhat.com>

internal/util/cryptsetup.go

@@ -0,0 +1,67 @@
+/*
+Copyright 2019 The Ceph-CSI Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package util
+
+import (
+	"bytes"
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+// LuksFormat sets up volume as an encrypted LUKS partition
+func LuksFormat(devicePath, passphrase string) (stdout, stderr []byte, err error) {
+	return execCryptsetupCommand(&passphrase, "-q", "luksFormat", "--hash", "sha256", devicePath, "-d", "/dev/stdin")
+}
+
+// LuksOpen opens LUKS encrypted partition and sets up a mapping
+func LuksOpen(devicePath, mapperFile, passphrase string) (stdout, stderr []byte, err error) {
+	return execCryptsetupCommand(&passphrase, "luksOpen", devicePath, mapperFile, "-d", "/dev/stdin")
+}
+
+// LuksClose removes existing mapping
+func LuksClose(mapperFile string) (stdout, stderr []byte, err error) {
+	return execCryptsetupCommand(nil, "luksClose", mapperFile)
+}
+
+// LuksStatus returns encryption status of a provided device
+func LuksStatus(mapperFile string) (stdout, stderr []byte, err error) {
+	return execCryptsetupCommand(nil, "status", mapperFile)
+}
+
+func execCryptsetupCommand(stdin *string, args ...string) (stdout, stderr []byte, err error) {
+	var (
+		program       = "cryptsetup"
+		cmd           = exec.Command(program, args...) // nolint: gosec, #nosec
+		sanitizedArgs = StripSecretInArgs(args)
+		stdoutBuf     bytes.Buffer
+		stderrBuf     bytes.Buffer
+	)
+
+	cmd.Stdout = &stdoutBuf
+	cmd.Stderr = &stderrBuf
+	if stdin != nil {
+		cmd.Stdin = strings.NewReader(*stdin)
+	}
+
+	if err := cmd.Run(); err != nil {
+		return stdoutBuf.Bytes(), stderrBuf.Bytes(), fmt.Errorf("an error (%v)"+
+			" occurred while running %s args: %v", err, program, sanitizedArgs)
+	}
+
+	return stdoutBuf.Bytes(), nil, nil
+}