feat(BRIDGE-356): Added retry logic for unavailable preferred keychain on Linux; Feature flag support before bridge initialization; Refactored some bits of the code;

internal/vault/storage/storage.go

@@ -0,0 +1,75 @@
+// Copyright (c) 2025 Proton AG
+//
+// This file is part of Proton Mail Bridge.
+//
+// Proton Mail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Proton Mail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Proton Mail Bridge. If not, see <https://www.gnu.org/licenses/>.
+
+package storage
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/sirupsen/logrus"
+)
+
+type JSONFile[T any] struct {
+	fileName string
+	fileType string
+}
+
+func NewJSONStorageFile[T any](fileName, fileType string) *JSONFile[T] {
+	return &JSONFile[T]{
+		fileName: fileName,
+		fileType: fileType,
+	}
+}
+
+func (jf *JSONFile[T]) Load(vaultDir string) (T, error) {
+	var result T
+	path := filepath.Join(vaultDir, jf.fileName)
+	bytes, err := os.ReadFile(path) //nolint:gosec
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			logrus.
+				WithFields(logrus.Fields{"pkg": "vault", "path": path}).
+				Tracef("%s file does not exists, default values will be used", jf.fileType)
+			return result, nil
+		}
+		return result, err
+	}
+
+	if err := json.Unmarshal(bytes, &result); err != nil {
+		return result, fmt.Errorf("%s file has invalid data: %w", jf.fileType, err)
+	}
+
+	return result, nil
+}
+
+func (jf *JSONFile[T]) Save(vaultDir string, data T) error {
+	bytes, err := json.MarshalIndent(data, "", "  ")
+	if err != nil {
+		return err
+	}
+
+	if err = os.MkdirAll(vaultDir, 0o700); err != nil {
+		return err
+	}
+
+	path := filepath.Join(vaultDir, jf.fileName)
+	return os.WriteFile(path, bytes, 0o600)
+}