Error when redirecting from Facebook login with python-social-auth, SqlAlchemy and Flask

Question

I am trying to implement social login in Flask using python-social-auth. It works in development on localhost, but not in production.

The error occurs when redirecting from login with Facebook. After debugging it seems to be caused by decoding in sql type pickle or json. I dug into the json module but have no idea how to fix it and I think it should not be fixed there since it is a built-in module.

Why does Facebook login work in development on localhost but not in production?

Exception on /complete/facebook/ [GET]
Traceback (most recent call last):
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/flask/app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/social/apps/flask_app/utils.py", line 46, in wrapper
    return func(backend, *args, **kwargs)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/social/apps/flask_app/routes.py", line 23, in complete
    *args, **kwargs)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/social/actions.py", line 43, in do_complete
    user = backend.complete(user=user, *args, **kwargs)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/social/backends/base.py", line 41, in complete
    return self.auth_complete(*args, **kwargs)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/social/utils.py", line 229, in wrapper
    return func(*args, **kwargs)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/social/backends/facebook.py", line 87, in auth_complete
    return self.do_auth(access_token, response, *args, **kwargs)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/social/backends/facebook.py", line 119, in do_auth
    return self.strategy.authenticate(*args, **kwargs)
File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/social/backends/base.py", line 82, in authenticate
    return self.pipeline(pipeline, *args, **kwargs)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/social/backends/base.py", line 85, in pipeline
    out = self.run_pipeline(pipeline, pipeline_index, *args, **kwargs)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/social/backends/base.py", line 112, in run_pipeline
    result = func(*args, **out) or {}
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/social/pipeline/social_auth.py", line 20, in social_user
    social = backend.strategy.storage.user.get_social_auth(provider, uid)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/social/storage/sqlalchemy_orm.py", line 136, in get_social_auth
    uid=uid)[0]
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2462, in __getitem__
    return list(self[item:item + 1])[0]
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2457, in __getitem__
    return list(res)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/sqlalchemy/orm/loading.py", line 86, in instances
    util.raise_from_cause(err)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/sqlalchemy/util/compat.py", line 200, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb, cause=cause)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/sqlalchemy/orm/loading.py", line 71, in instances
    rows = [proc(row) for row in fetch]
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/sqlalchemy/orm/loading.py", line 428, in _instance
    loaded_instance, populate_existing, populators)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/sqlalchemy/orm/loading.py", line 486, in _populate_full
    dict_[key] = getter(row)
  File "/home/dev/huugbaan/xxvenv/lib/python2.7/site-packages/sqlalchemy/sql/sqltypes.py", line 1258, in process
    return loads(value)
  File "/usr/local/lib/python2.7.12/lib/python2.7/json/__init__.py", line 339, in loads
    return _default_decoder.decode(s)
  File "/usr/local/lib/python2.7.12/lib/python2.7/json/decoder.py", line 364, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
TypeError: expected string or buffer
[pid: 5053|app: 0|req: 6/26] 171.99.3.44 () {42 vars in 1892 bytes} [Sun Jul 17 02:09:00 2016] GET /complete/facebook/?redirect_state=i2C8teuxp7n3o39bhzK8Ypwa8S2O1EzC&code=AQBim0qoaEqukud-ysEQpuhyhy63v729wxqQ5qo3HTYRFSerzQrCgjXVKUu-EA1A1A5CXbAfzvZHb87K4moaxt0Wk4g5mhQQQ--ovb9NygFUybyznSk-09O8x-zB5CXSyFVR-fDV54CXSNbhBOJJvPWQu9rJ0QlGj53kEDFyKCgXA0-gHyLIXfDveY-3Z_nouWv0mosSogs9JSE06EQ9ZfZh87HKJkihEcnAs_QhO3eHhkZ5uqf7ZSWc-Soj2c4XXVEG38aR5Ltl-cv7tWkwAsKFtW36nBcF0NzEhDiuSYaiTIn-nZBnRBveO7PFrDJRj6GEts1tc9pY29KnZuA72YwN&state=i2C8teuxp7n3o39bhzK8Ypwa8S2O1EzC => generated 4571 bytes in 587 msecs (HTTP/1.1 500) 2 headers in 100 bytes (1 switches on core 0)

Answer 1

just do dirty fix at sqltype.py of sqlalchemy package after debugging. I found out the different of type of value in method below. so I decided to skip and return the value if it is already dict.

1245     def result_processor(self, dialect, coltype):
1246         impl_processor = self.impl.result_processor(dialect, coltype)
1247         loads = self.pickler.loads
1248         if impl_processor:
1249             def process(value):
1250                 value = impl_processor(value)
1251                 if value is None:
1252                     return None
1253                 return loads(value)
1254         else:
1255             def process(value):
1256                 if value is None:
1257                     return None
#### ->>>            if type(value) is dict: return value
1258                 return loads(value) 
1259         return process

if type(value) is dict: return value at line 1258