初始化项目框架，完成部分接口开发

utility/oss/oss.go

@@ -0,0 +1,26 @@
+package oss
+
+import (
+	"context"
+	"server/internal/model"
+)
+
+// OssClient 是所有云存储平台要实现的统一接口
+type OssClient interface {
+	UploadFile(ctx context.Context, in *model.OssUploadFileInput) (out *model.OssOutput, err error)
+	GetFileURL(ctx context.Context, in *model.OssGetFileInput) (out *model.OssOutput, err error)
+}
+
+// registry 存储各个平台的实现
+var clients = make(map[string]OssClient)
+
+// Register 用于注册平台实现
+func Register(name string, client OssClient) {
+	clients[name] = client
+}
+
+// GetClient 获取指定平台的实现
+func GetClient(name string) (OssClient, bool) {
+	client, ok := clients[name]
+	return client, ok
+}