refactor(api): restructure bolt package (#1981)

* refactor(api): bolt package refactor

* refactor(api): refactor bolt package

api/bolt/settings/settings.go

@@ -0,0 +1,48 @@
+package settings
+
+import (
+	"github.com/portainer/portainer"
+	"github.com/portainer/portainer/bolt/internal"
+
+	"github.com/boltdb/bolt"
+)
+
+const (
+	// BucketName represents the name of the bucket where this service stores data.
+	BucketName  = "settings"
+	settingsKey = "SETTINGS"
+)
+
+// Service represents a service for managing endpoint data.
+type Service struct {
+	db *bolt.DB
+}
+
+// NewService creates a new instance of a service.
+func NewService(db *bolt.DB) (*Service, error) {
+	err := internal.CreateBucket(db, BucketName)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Service{
+		db: db,
+	}, nil
+}
+
+// Settings retrieve the settings object.
+func (service *Service) Settings() (*portainer.Settings, error) {
+	var settings portainer.Settings
+
+	err := internal.GetObject(service.db, BucketName, []byte(settingsKey), &settings)
+	if err != nil {
+		return nil, err
+	}
+
+	return &settings, nil
+}
+
+// UpdateSettings persists a Settings object.
+func (service *Service) UpdateSettings(settings *portainer.Settings) error {
+	return internal.UpdateObject(service.db, BucketName, []byte(settingsKey), settings)
+}