Uploading blob to BlobStore from python returns 500 on http

Question

I am trying to upload a blob to BlobStore from python and it works when on https://...appspot.com and https://...com/ but when the exact same code is executed from http it does not work and BlobStore returns 500 error.

I have tried making the connection always secure even even when not.

Here is my code:

@staticmethod
def save_to_blobstore(_request, id, file_contents, file_type, file_name = 'fixmeh.png'):
    upload_url  = blobstore.create_upload_url('/upload-item/blob-key/{}'.format(id))

    if upload_url.startswith('http://') and 'localhost.com' not in _request.get_host():
        upload_url = 'https' + upload_url[4:]

    # ----- CREATING FORMDATA -----
    boundary = 'WebKitFormBoundaryE19zNvXGzXaLvS5C'
    body = '\r\n'.join([
        '--' + boundary,
        'Content-Disposition: form-data; name="file"; filename="{}"'.format(file_name),
        'Content-Type: {}'.format(file_type),
        '',
        file_contents,
        '',
        '--' + boundary + '--',
        '',
    ])

    headers = {
        'Content-Type'  : 'multipart/form-data; boundary={}'.format(boundary),
        'User-Agent'    : 'Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Firefox/31.0',
    }

    logging.critical('blobstore save')

    # TODO Why the hell do we receive deadline limit exceeded?
    request = urllib2.Request(upload_url)

    # ----- FORCING SECURE CONNECTION EXCEPT ON LOCALHOST -----
    if 'localhost.com' in _request.get_host():
        conn = httplib.HTTPConnection(request.get_host(), timeout = 50)
    else:
        conn = httplib.HTTPSConnection(request.get_host(), timeout = 50)

    conn._follow_redirects = True

    logging.info(['upload_url', upload_url ])
    logging.info(['get_host', request.get_host() ])
    logging.info(['get_selector', request.get_selector() ])
    conn.request('POST', request.get_selector(), body, headers)

    try:
        response = conn.getresponse()
        response_body = response.read()

        logging.info(response_body)

        # TODO we need to have an exception if the response is not 200
    except DeadlineExceededError:
        logging.exception('Saving blob - DeadlineExceededError')
    except:
        logging.exception('Saving blob')

When executed through HTTP this is the return from BlobStore, though it does not help a lot. Is there a way to log blobstore error in https://console.developers.google.com/project/.../logs or anywhere else.

<html><head>
<meta http-equiv="content-type" content="text/html;charset=utf-8">
<title>500 Server Error</title></head>
<body text=#000000 bgcolor=#ffffff>
<h1>Error: Server Error</h1>
<h2>The server encountered an error and could not complete your request.
<p>Please retry your last submission.</p>
<p>If the problem persists, please contact the person responsible for the application you're using, or, if you are that person,
<a href="http://code.google.com/appengine/community.html">report</a> your
problem and mention this error message and the query that caused it.</h2>
</body></html>

Can you help me with any ideas why the may not work on http but works on https. (NOTE it works with http on the SDK - no ssl there, this is only happening on appspot)

What error is in your logs? You have two logging.exception calls with string arguments. Do they appear? — Josh J

voscausa voscausa · Accepted Answer · 2015-09-14T13:43:50

I used this code for the full upload url using webapp2 routing:

upload_url = create_upload_url(webapp2.uri_for('blob_update', _full=True))

And the handler uses a webapp2 named route: 'blob_update'

class BlobUpdate(blobstore_handlers.BlobstoreUploadHandler):
    """ has named route : blob_update : 
    webapp2.Route(r'/blob_update', handler='....BlobUpdate', name='blob_update') """

    def post(self):
        """ blob upload handler returns the new blobkey"""

    blob_info = self.get_uploads('file')[0]
    ....

More here: App Engine update blob

Uploading blob to BlobStore from python returns 500 on http

2 Answers