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/credentials.go

@@ -0,0 +1,126 @@
+/*
+Copyright 2018 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 (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+)
+
+const (
+	credUserID           = "userID"
+	credUserKey          = "userKey"
+	credAdminID          = "adminID"
+	credAdminKey         = "adminKey"
+	credMonitors         = "monitors"
+	tmpKeyFileLocation   = "/tmp/csi/keys"
+	tmpKeyFileNamePrefix = "keyfile-"
+)
+
+type Credentials struct {
+	ID      string
+	KeyFile string
+}
+
+func storeKey(key string) (string, error) {
+	tmpfile, err := ioutil.TempFile(tmpKeyFileLocation, tmpKeyFileNamePrefix)
+	if err != nil {
+		return "", fmt.Errorf("error creating a temporary keyfile (%s)", err)
+	}
+	defer func() {
+		if err != nil {
+			// don't complain about unhandled error
+			_ = os.Remove(tmpfile.Name())
+		}
+	}()
+
+	if _, err = tmpfile.Write([]byte(key)); err != nil {
+		return "", fmt.Errorf("error writing key to temporary keyfile (%s)", err)
+	}
+
+	keyFile := tmpfile.Name()
+	if keyFile == "" {
+		err = fmt.Errorf("error reading temporary filename for key (%s)", err)
+		return "", err
+	}
+
+	if err = tmpfile.Close(); err != nil {
+		return "", fmt.Errorf("error closing temporary filename (%s)", err)
+	}
+
+	return keyFile, nil
+}
+
+func newCredentialsFromSecret(idField, keyField string, secrets map[string]string) (*Credentials, error) {
+	var (
+		c  = &Credentials{}
+		ok bool
+	)
+
+	if len(secrets) == 0 {
+		return nil, errors.New("provided secret is empty")
+	}
+	if c.ID, ok = secrets[idField]; !ok {
+		return nil, fmt.Errorf("missing ID field '%s' in secrets", idField)
+	}
+
+	key := secrets[keyField]
+	if key == "" {
+		return nil, fmt.Errorf("missing key field '%s' in secrets", keyField)
+	}
+
+	keyFile, err := storeKey(key)
+	if err == nil {
+		c.KeyFile = keyFile
+	}
+
+	return c, err
+}
+
+func (cr *Credentials) DeleteCredentials() {
+	// don't complain about unhandled error
+	_ = os.Remove(cr.KeyFile)
+}
+
+func NewUserCredentials(secrets map[string]string) (*Credentials, error) {
+	return newCredentialsFromSecret(credUserID, credUserKey, secrets)
+}
+
+func NewAdminCredentials(secrets map[string]string) (*Credentials, error) {
+	return newCredentialsFromSecret(credAdminID, credAdminKey, secrets)
+}
+
+func NewCredentials(id, key string) (*Credentials, error) {
+	var c = &Credentials{}
+
+	c.ID = id
+	keyFile, err := storeKey(key)
+	if err == nil {
+		c.KeyFile = keyFile
+	}
+
+	return c, err
+}
+
+func GetMonValFromSecret(secrets map[string]string) (string, error) {
+	if mons, ok := secrets[credMonitors]; ok {
+		return mons, nil
+	}
+	return "", fmt.Errorf("missing %q", credMonitors)
+}