从python + flask + gunicorn + nginx + Compute Engine应用程序中读取来自Google Cloud Storage的文件失败

Question

Reading of a file downloaded from Google Cloud Storage fails in a python + flask + gunicorn + nginx + Compute Engine app. Link to the code: https://github.com/samuq/CE-test . The line number 64 of the file 'ETL_SHP_READ_SQL_WRITE' returns nothing, although the file is valid and has data in it:

prj_blob.download_to_file(self.prj_file)
logger.log_text(self.prj_file)
line 64 -->       euref_fin.ImportFromWkt(self.prj_file.read())).

Answer 1

file.seek(0) helped to solve the problem; somehow I assume that after blob.download_to_file(file_name) the file reader isn't in the start of the file. Code:

    try:
        fd, path = tempfile.mkstemp()
        with os.fdopen(fd, 'w+') as prj_file:
            # do stuff with temp file
            prj_blob.download_to_file(prj_file)
            prj_file.seek(0)
            euref_fin.ImportFromWkt(prj_file.read())
            logger.log_text(str(euref_fin))
            logger.log_text('euref_fin printed!')
    finally:
        os.remove(path)