Question

我使用flask和flask-restplus为我的应用程序生成了一个上传api端点。一切似乎工作正常，但收到的文件数据为空，然后保存的文件为空。

这是我的代码

upload_parser = reqparse.RequestParser()
upload_parser.add_argument('data', location='files', type=FileStorage, required=True)
 ...

@ns.route('/upload')
class Upload(Resource):

    @api.expect(upload_parser)
    def post(self):
        args = upload_parser.parse_args()
        uploaded_file = args['data']  # This is FileStorage instance
        scan_for_virus(uploaded_file)  # This function raised error if a virus are found
        destination = current_app.config.get('UPLOAD_DATA_FOLDER')
        if not os.path.exists(destination):
            os.makedirs(destination)
        temp_filename = os.path.join(destination, str(uuid.uuid4()))

        print uploaded_file  # print "<FileStorage: u'IMG-20190129-WA0001.jpg' ('image/jpeg')>" seems correct
        print uploaded_file.stream  # print "<tempfile.SpooledTemporaryFile instance at 0x104b1c3f8>}"
        print uploaded_file.content_length  # print "0" ..... but my orignal file size is 4352436 bytes
        uploaded_file.save(temp_filename)  # create the file with the correct path, but this new file is empty.
        return {'url': 'upload://{0}'.format(os.path.basename(temp_filename))}, 202

我使用swagger接口（由restplus框架生成）来上传文件。发送的请求是：

curl -X POST "http://localhost:8888/api/upload" -H "accept: application/json" -H "Content-Type: multipart/form-data" -F "data=@my_file.pdf;type=application/pdf"

您对解决我的问题有什么建议吗？我需要在烧瓶配置中指定一些特殊的内容吗？谢谢您的帮助

雷诺（Renaud）

Answer 1

好，我找到了问题。...问题出在我的scan_for_virus函数中：

def scan_for_virus(uploaded_file):
    try:
        cd = pyclamd.ClamdUnixSocket(current_app.config.get('CLAMAV_SOCKET_FILE', '/tmp/clamd.socket'))
        cd.ping()
    except pyclamd.ConnectionError as ce:
        log.error("Unable to connect to Clamd :: "+str(ce))
        abort(500, str(ce))
    scan_result = cd.scan_stream(uploaded_file.stream)
    if scan_result is not None:  # In this case ClamAV found a virus !
        log.warning("Virus found into {0} :: {1}".format(uploaded_file.filename, scan_result['stream'][1]))
        abort(502, "Virus found !", detail=scan_result['stream'][1])

如您所见，scan_stream使用uploaded_file.stream属性读取upload_file内容。但是FileStorage.save()函数也使用stream属性，因此我需要在第一次读取后重置流：

....
scan_result = cd.scan_stream(uploaded_file.stream)
uploaded_file.stream.seek(0)
....

只要这样做，它就会按预期工作。

病毒扫描后，FileStorage文件似乎为空

1 个答案: