Firebase管理SDK上传文件到Google云存储

Question

func main() {
   config := &firebase.Config{
      ProjectID:     "myproject-id",
      StorageBucket: "myproject-id.appspot.com",
   }
   credentialsJSON := os.Getenv("GOOGLE_CREDENTIALS")
   creds := google.Credentials{JSON: []byte(credentialsJSON)}
   opt := option.WithCredentials(&creds)

   app, err := firebase.NewApp(context.Background(), config,
    opt)

   if err != nil {
     log.Fatalln(err)
   }
   ctx, cancel := context.WithTimeout(context.Background(), time.Second*50)
   defer cancel()

   client, err := app.Storage(ctx)
   if err != nil {
     log.Fatalln(err)
   }
   fmt.Println(client)

   bucket, err := client.DefaultBucket()

   object := bucket.Object("foo.png")
   wc := object.NewWriter(ctx)

   r, err := os.Open("/Users/foo/test.png")
   defer r.Close()

   if _, err = io.Copy(wc, r); err != nil {
      log.Error(err)
   }

   if err := wc.Close(); err != nil {
     fmt.Println(err)
     log.Error(err)
   }
}

 Post "https://storage.googleapis.com/upload/storage/v1/b/myproject-id.appspot.com/o?alt=json&name=foo.png&prettyPrint=false&projection=full&uploadType=multipart": oauth2: Transport's Source is nil

Firebase Admin SDK文档清楚地说明，服务帐户对存储帐户具有完全的范围控制，但由于传输令牌源为nil，因此正确引导凭据似乎有些错误。