How to emit websocket message from outside a websocket endpoint? - python

I'm building a website using Flask in which I also use Websockets using Flask-socketIO, but there's one thing I don't understand.
I built a chat-functionality. When one user sends a message I use websockets to send that message to the server, after which I emit the message to the other user from within that same call:
#socketio.on('newPM', namespace='/test')
#login_required_with_global
def io_newMessage(theJson):
emit('message', {'message': theJson['message']}, room=str(theJson['toUserId']))
But let's say that I want to emit a message to a user when a file was saved. This means that I need to emit a message from within the view in which the file is POSTed. So according to the flask_socketio docs I can add a namespace in the emit. So I wrote this:
#app.route('/doc', methods=['POST'])
#login_required
def postDoc():
saveDocument(request.files['file'], g.user.id)
emit('my response', {'data': 'A NEW FILE WAS POSTED'}, room=current_user.id, namespace='/test')
return jsonify({'id': str(doc.id)})
But seeing the stacktrace below there still is a problem with the namespace; werkzeug has an AttributeError: 'Request' object has no attribute 'namespace'.
Does anybody know what I'm doing wrong here? Or is this a bug in flask_socketio? All tips are welcome!
Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1820, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1403, in handle_exception
reraise(exc_type, exc_value, tb)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1477, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1381, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1475, in full_dispatch_request
rv = self.dispatch_request()
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1461, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/usr/local/lib/python2.7/dist-packages/flask_login.py", line 758, in decorated_view
return func(*args, **kwargs)
File "/home/vg/app/views.py", line 768, in emitNotificationCount
emit('menuInit', emitJson, room=current_user.id, namespace='/test')
File "/usr/local/lib/python2.7/dist-packages/flask_socketio/__init__.py", line 444, in emit
return request.namespace.emit(event, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/werkzeug/local.py", line 338, in __getattr__
return getattr(self._get_current_object(), name)
AttributeError: 'Request' object has no attribute 'namespace'

Quoting from Miguel Grinberg's response on an open issue page on the Flask-SocketIO GitHub:
When you want to emit from a regular route you have to use
socketio.emit(), only socket handlers have the socketio context
necessary to call the plain emit().
So as an example:
from flask_socketio import SocketIO
app = Flask(__name__)
app.config.from_object('config')
socketio = SocketIO(app)
#app.route('/doc', methods=['POST'])
def postDoc():
saveDocument(request.files['file'], g.user.id)
socketio.emit('my response', {'data': 'A NEW FILE WAS POSTED'}, room=current_user.id)
return jsonify({'id': str(doc.id)})

Related

Python Flask routing - how to get parameter from MethodView class

In my new job we are using the Flask framework (I'm newbie in the Flask). Every view is the child of MethodView. The code looks like this:
from flask import render_template
from flask.views import MethodView
class HelloWorldPage(MethodView):
def get(self):
return render_template('helloworld.html')
def configure_routing(app):
app.add_url_rule('/<lang>/helloworld', view_func=HelloWorldPage.as_view('helloworld'))
Of course, configure_routing(app) from helloworld.py is called in appropriate place. Now, my question is if it's possible to get <lang> from route? When I write get(self, lang) it throws an exception TypeError: get() takes exactly 2 arguments (1 given), when I create a method called helloworld(lang), it throws me that method get is not implemented and so on. Thank you very much. Bye
Edit:
traceback to get(self, lang)
Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1994, in __call__
return self.wsgi_app(environ, start_response)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1985, in wsgi_app
response = self.handle_exception(e)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1540, in handle_exception
reraise(exc_type, exc_value, tb)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1982, in wsgi_app
response = self.full_dispatch_request()
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1614, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1517, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1612, in full_dispatch_request
rv = self.dispatch_request()
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1598, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/usr/local/lib/python2.7/dist-packages/flask/views.py", line 84, in view
return self.dispatch_request(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/flask/views.py", line 149, in dispatch_request
return meth(*args, **kwargs)
TypeError: get() takes exactly 2 arguments (1 given)
I tried the same
from flask import Flask, render_template
from flask.views import MethodView
app = Flask(__name__)
class HelloWorldPage(MethodView):
def get(self, lang):
return render_template('HelloWorld.html', language=lang)
app.add_url_rule('/<lang>/helloworld', view_func=HelloWorldPage.as_view('helloworld'))
if __name__ == '__main__':
app.run()
response below
comment from flask.views
METHODVIEW :
Like a regular class-based view but that dispatches requests to
particular methods. For instance if you implement a method called
:meth:get it means it will respond to 'GET' requests and
the :meth:dispatch_request implementation will automatically
forward your request to that. Also :attr:options is set for you
automatically::
Did you restrart the service after changing get(self) to get(self, lang) ?
if you did then please check the application init file where you import HelloWorldPage view and make sure
app = Flask(__name__)
## IMPORT YOUR APP VIEWS
## THEN CONFIGURE THE ROUTINGS
def configure_routing(app):
app.add_url_rule('/<lang>/helloworld', view_func=HelloWorldPage.as_view('helloworld'))

KeyError: u'FLASK_AUTH_REALM'

I impemented today https://pypi.python.org/pypi/flask-htpasswd/ on my site and I'm getting KeyError: u'FLASK_AUTH_REALM' error. What I did was putting app.config's before Class so it looks like here:
from .utils import now, dottedQuadToNum, get_blacklist
log = logging.getLogger(__name__)
compress = Compress()
import flask
from flask_htpasswd import HtPasswdAuth
app = flask.Flask(__name__)
app.config['FLASK_HTPASSWD_PATH'] = 'C:/.htpasswd'
app.config['FLASK_SECRET'] = 'Hey Hey Kids, secure me!'
htpasswd = HtPasswdAuth(app)
class Pogom(Flask):
def __init__(self, import_name, **kwargs):
And here's an error that I'm getting
Traceback (most recent call last):
File "C:\Python27\lib\site-packages\flask\app.py", line 1997, in __call__
return self.wsgi_app(environ, start_response)
File "C:\Python27\lib\site-packages\flask\app.py", line 1985, in wsgi_app
response = self.handle_exception(e)
File "C:\Python27\lib\site-packages\flask\app.py", line 1540, in handle_exception
reraise(exc_type, exc_value, tb)
File "C:\Python27\lib\site-packages\flask\app.py", line 1982, in wsgi_app
response = self.full_dispatch_request()
File "C:\Python27\lib\site-packages\flask\app.py", line 1614, in full_dispatch_request
rv = self.handle_user_exception(e)
File "C:\Python27\lib\site-packages\flask\app.py", line 1517, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "C:\Python27\lib\site-packages\flask\app.py", line 1612, in full_dispatch_request
rv = self.dispatch_request()
File "C:\Python27\lib\site-packages\flask\app.py", line 1598, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "C:\Python27\lib\site-packages\flask_htpasswd.py", line 205, in decorated
return self.auth_failed()
File "C:\Python27\lib\site-packages\flask_htpasswd.py", line 159, in auth_failed
current_app.config['FLASK_AUTH_REALM']
KeyError: u'FLASK_AUTH_REALM'
You do not show the complete code. I guess you want to declare the Pogom class which derive from Flask class, then declare an instance from Pogom, and execute pogom.run.
According to the exception stack, I think missing FLASK_AUTH_REALM key in app.config.
Why the FLASK_AUTH_REALM missing?
First, the flask_htpasswd extension will set the default value for FLASK_AUTH_REALM in init_app function.
But you declare one new class, and may be instance one app from Pogom and app.run. the flask_htpasswd just initialize the old app which is the instance Flask, and the new app does not have proper FLASK_AUTH_REALM key in config.
So, I try to show some code like below:
from flask import Flask
from flask_htpasswd import HtPasswdAuth
class Pogom(Flask):
def __init__(self, import_name, **kwargs):
# missing some special code
super(Pogom, self).__init__(import_name, **kwargs)
htpasswd = HtPasswdAuth()
def create_app():
app = Pogom(__name__)
app.config['FLASK_HTPASSWD_PATH'] = 'C:/.htpasswd'
app.config['FLASK_SECRET'] = 'Hey Hey Kids, secure me!'
htpasswd.init_app(app)
return app
if __name__ == '__main__':
app = create_app()
# just for demonstration
#app.route('/')
#htpasswd.required
def index():
return "Hello"
app.run()

How do I configure a Flask app inside a Docker container to parse a large MessagePack object?

I'm getting the following when sending a very large POST to a Flask application.
Logs:
restful stderr | /usr/local/lib/python2.7/dist-packages/werkzeug/filesystem.py:63: BrokenFilesystemWarning: Detected a misconfigured UNIX filesystem: Will use UTF-8 as filesystem encoding instead of 'ANSI_X3.4-1968'
BrokenFilesystemWarning)
restful stderr | 172.19.0.5 - - [25/Apr/2017 00:05:40] "POST /ml/source/ HTTP/1.1" 500 -
restful stderr | Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1836, in __call__
return self.wsgi_app(environ, start_response)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1820, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1403, in handle_exception
reraise(exc_type, exc_value, tb)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1477, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1381, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1475, in full_dispatch_request
rv = self.dispatch_request()
File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1461, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/opt/fish/bizco/ml/restful.py", line 49, in index
job = q.enqueue_call(func=process_request, args=(postObject,), result_ttl=5000, timeout=36000)
File "/usr/local/lib/python2.7/dist-packages/rq/queue.py", line 216, in enqueue_call
job = self.enqueue_job(job, at_front=at_front)
File "/usr/local/lib/python2.7/dist-packages/rq/queue.py", line 282, in enqueue_job
pipe.execute()
File "/usr/local/lib/python2.7/dist-packages/redis/client.py", line 2641, in execute
return execute(conn, stack, raise_on_error)
File "/usr/local/lib/python2.7/dist-packages/redis/client.py", line 2495, in _execute_transaction
connection.send_packed_command(all_cmds)
File "/usr/local/lib/python2.7/dist-packages/redis/connection.py", line 556, in send_packed_command
(errno, errmsg))
ConnectionError: Error 104 while writing to socket. Connection reset by peer.
Route Code:
#app.route('/zebra/', methods=['GET', 'POST'])
def index():
print "/zebra/ called:")
if request.method == "POST":
state = True
if request.headers['Content-Type'] == 'application/x-msgpack':
print 'Found MsgPack'
postObject = msgpack.unpackb(request.data)
else:
print 'Content type not correct'
state = False
if state == True:
json = jsonify(...)
else:
# return an error
json = jsonify...)
return json
The POST object contains a MessagePack encoded payload, but it never enters my route handler. I see no log statement inside the handler block.
This only seems to happen when the payload is above 200MB. How do I get flask to store handle properly?

Python Flask failing on combined GET and POST request

I'm writing a function in Python Flask to deal with the oauth2 call backs of multiple api's.
The function as it stands is:
#app.route('/external_api/<api>/oauth2callback', methods=['POST', 'GET'])
def gdrive_oauth2callback(api):
toReturn = external_api.APIs[api]['lib'].oauth2callback(os.path.join(APP_OAUTH, str(api + '_id.json')))
userSession = UserSession()
userSession.addUserAuth(api)
return toReturn
However this causes a build error:
raise BuildError(endpoint, values, method)
BuildError: ('gdrive_oauth2callback', {}, None)
I'm confused as to why this is happening, as when i replace the api variable with the string 'gdrive' no error is created and it works perfectly. I'm calling the function in the same manner on both occasions (example.com/external_api/gdrive/oauth2callback), I'm wondering if Flask is unable to deal with both a POST request and a GET request at the same time, and if anyone else has had the same issue?
The full error log is below:
ERROR:app:Exception on /external_api/gdrive/connect [GET]
Traceback (most recent call last):
File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
rv = self.dispatch_request()
File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/app/app/views.py", line 43, in gdrive_connect
toReturn = external_api.APIs[api]['lib'].makeConnection()
File "/app/app/external_api/gdrive/api.py", line 14, in makeConnection
return flask.redirect(flask.url_for('gdrive_oauth2callback'))
File "/app/.heroku/python/lib/python2.7/site-packages/flask/helpers.py", line 312, in url_for
return appctx.app.handle_url_build_error(error, endpoint, values)
File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1641, in handle_url_build_error
reraise(exc_type, exc_value, tb)
File "/app/.heroku/python/lib/python2.7/site-packages/flask/helpers.py", line 305, in url_for
force_external=external)
File "/app/.heroku/python/lib/python2.7/site-packages/werkzeug/routing.py", line 1616, in build
raise BuildError(endpoint, values, method)
BuildError: ('gdrive_oauth2callback', {}, None) - at=info method=GET path
If anyone could give me any pointers on this that would be great! Thanks!
I think that flask must not be failing, if you take a look to this example, it works perfectly, http://flask.pocoo.org/snippets/62/.
I tried:
from flask import Flask
app = Flask(__name__)
#app.route("/<name>",methods=['POST', 'GET'])
def hello(name):
return "Hello World!"+name
if __name__ == "__main__":
app.run()
and it works fine on post and get requests. I know that isnt enougth but it shows what the problem probably isn’t.

Flask: token-based authorization

I am building a basic app with Flask: it has a unique route that requests just a token authentication, i.e. if the token provided in the headers is correct, then the request is satisfied. To do so, I installed both Flask and Flask-Security. This is a snippet of my app:
from flask import Flask
from flask.ext.security import auth_token_required
from flask.ext.security import Security
app = Flask(__name__)
app.config['SECURITY_TOKEN_AUTHENTICATION_KEY'] = 'mytoken'
security = Security(app)
#app.route('/myurl')
#auth_token_required
def myrequest():
return 'OK'
if __name__ == '__main__':
app.run(debug=True)
I test it by running:
$ curl -H 'Authorization: Token token="mytoken"' localhost:5000/myurl
or even:
$ curl localhost:5000/myurl
However, I get the following error:
Traceback (most recent call last):
File "/Users/username/.virtualenvs/my_env/lib/python2.7/site-packages/flask/app.py", line 1836, in __call__
return self.wsgi_app(environ, start_response)
File "/Users/username/.virtualenvs/my_env/lib/python2.7/site-packages/flask/app.py", line 1820, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/Users/username/.virtualenvs/my_env/lib/python2.7/site-packages/flask/app.py", line 1403, in handle_exception
reraise(exc_type, exc_value, tb)
File "/Users/username/.virtualenvs/my_env/lib/python2.7/site-packages/flask/app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "/Users/username/.virtualenvs/my_env/lib/python2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/Users/username/.virtualenvs/my_env/lib/python2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/Users/username/.virtualenvs/my_env/lib/python2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
rv = self.dispatch_request()
File "/Users/username/.virtualenvs/my_env/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/Users/username/.virtualenvs/my_env/lib/python2.7/site-packages/flask_security/decorators.py", line 113, in decorated
if _check_token():
File "/Users/username/.virtualenvs/my_env/lib/python2.7/site-packages/flask_security/decorators.py", line 50, in _check_token
header_key = _security.token_authentication_header
File "/Users/username/.virtualenvs/my_env/lib/python2.7/site-packages/werkzeug/local.py", line 338, in __getattr__
return getattr(self._get_current_object(), name)
File "/Users/username/.virtualenvs/my_env/lib/python2.7/site-packages/werkzeug/local.py", line 297, in _get_current_object
return self.__local()
File "/Users/username/.virtualenvs/my_env/lib/python2.7/site-packages/flask_security/decorators.py", line 24, in <lambda>
_security = LocalProxy(lambda: current_app.extensions['security'])
KeyError: 'security'
Do you know where the error lies? Is it in the app or in some conflicts among the Flask libraries?
EDIT: added Security(app) initialization
user_datastore = SQLAlchemyUserDatastore(db, User, Role)
security = Security(app, user_datastore)

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