feature(manager): skeleton for worker-manager communication

manager/db.go

@@ -0,0 +1,23 @@
+package manager
+
+import "github.com/boltdb/bolt"
+
+type dbAdapter interface {
+	GetWorker(workerID string)
+	UpdateMirrorStatus(workerID, mirrorID string, status mirrorStatus)
+	GetMirrorStatus(workerID, mirrorID string)
+	GetMirrorStatusList(workerID string)
+	Close()
+}
+
+type boltAdapter struct {
+	db     *bolt.DB
+	dbFile string
+}
+
+func (b *boltAdapter) Close() error {
+	if b.db != nil {
+		return b.db.Close()
+	}
+	return nil
+}