I am using Python Google Classroom API to retrieve announcements data.
Here is my code.
from fetch import Fetch
from googleapiclient.discovery import build
cred = 'catp.json'
get_credits = Fetch(cred) #fetching credential data
credit = get_credits()
service = build('Classroom', 'v1', credentials=credit)
setup = service.courses()
data = setup.list().execute()['courses']
course_names = []
course_ids = []
for i in range(len(data)):
course_names.append(data[i]['name'])
course_ids.append(data[i]['id'])
announcement_data = setup.announcements().list(courseId=course_ids[0]).execute()
But I receive the following Traceback Error:
Additional Information:
My project is registered under service account.
My role is Owner.
I have students account on Google Classroom.
To check whether the same error would be called if I tried to access announcements from a teachers account I created a Course in Classroom, using my Students account and posted some demo announcements.
The result was the same TracebackError. I also tried getting access to the data using API Explorer from Google, passing the same course ID as an argument. The data was received normally without any errors.
[Edit]
Here is the code for fetching credentials, Fetch(cred):
import os
import pickle
from google_auth_oauthlib.flow import InstalledAppFlow
from google.auth.transport.requests import Request
class Fetch:
def __init__ (self, credential_filename):
self.scopes = ['https://www.googleapis.com/auth/classroom.courses.readonly',
'https://www.googleapis.com/auth/classroom.announcements',
]
self.path = 'C:/frank/programs/python/google api'
self.credential_file = credential_filename
def __call__(self):
os.chdir(self.path)
token = open('token.pickle', 'rb')
creds = pickle.load(token)
if creds.valid == False:
if creds.expired == True:
creds.refresh(Request())
else:
try:
flow = InstalledAppFlow.from_client_secrets_file(self.credential_file, self.scopes)
creds = flow.run_local_server(port=0)
except FileNotFoundError:
print(f'{self.credential_file} does not exist')
token = open(self.token_file, 'wb')
pickle.dump(creds, token)
return creds
I am working on a simple flask Todo list web app with postgres database and I tried deploying it to heroku but it is giving me an error saying
Application error
An error occurred in the application and your page could not be served. If you are the application owner, check your logs for details.
I followed the Quickstart correctly but that did not help
when I check logs by heroku logs --tail It says
ModuleNotFoundError:No module named TodoApp
There are no error logs on command promt also. I can not find any way to check what is going wrong.
This is in my Procfile
web: gunicorn TodoApp:app
This is in my requirements.txt
asn1crypto==0.22.0
certifi==2017.4.17
cffi==1.10.0
chardet==3.0.4
click==6.7
cryptography==1.9
enum34==1.1.6
Flask==0.12.2
Flask-SQLAlchemy==2.2
Flask-WTF==0.14.2
gunicorn==19.7.1
idna==2.5
ipaddress==1.0.18
itsdangerous==0.24
Jinja2==2.9.6
MarkupSafe==1.0
psycopg2==2.7.1
pycparser==2.17
PyJWT==1.5.0
pyOpenSSL==17.0.0
pytz==2017.2
requests==2.18.1
six==1.10.0
SQLAlchemy==1.1.10
twilio==6.4.1
urllib3==1.21.1
Werkzeug==0.12.2
WTForms==2.1
This is my todo.py file
from flask import Flask, render_template , Response
from flask import request , jsonify
from models import db ,db1, User
from flask_sqlalchemy import SQLAlchemy
from message import client
import json
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] =
'postgresql://postgres:Abcd#123456#localhost/learningflask'
db.init_app(app)
#app.route("/")
def index():
return render_template("index.html",User=User.query.all())
#app.route("/getdata", methods=['GET'])
def get_User():
myuser=User.query.all()
if myuser =="":
return 404
return Response(json.dumps({'taskname':[user.taskname for user in
myuser]}), mimetype='application/json')
#app.route('/', methods=['POST'])
def my_form_post():
text=request.form['text']
if text !="":
newuser = User(text)
db.session.add(newuser)
db.session.commit()
message = client.messages.create(
to="", from_="" , body ="A task has
been added to your todo list : "+ text)
print(message.sid)
return render_template("index.html",User=User.query.all())
else:
newuser = request.form.getlist('removeId')
if newuser:
for n in newuser:
User.query.filter_by(uid=n).delete()
db.session.commit()
return render_template("index.html",User=User.query.all())
else:
edituser = request.form.getlist('editId')
if edituser:
updatedText=request.form['updatedText']
for e in edituser:
User.query.filter_by(uid=e).update(dict(taskname=updatedText))
db.session.commit()
return
render_template("index.html",User=User.query.all())
if __name__ == "__main__":
app.run(debug=True)
db.create_all()
Here is the folder structure
The error might be in this line:
web: gunicorn TodoApp:app
you should use the file name before the : and then the flask object you have created.
web: gunicorn Todo:app
this should work. toto:app is the <filename>:<appname> .
We want to use django-channels for our websockets but we need to authenticate as well. We have a rest api running with django-rest-framework and there we use tokens to authenticate a user, but the same functionality does not seem to be built into django-channels.
For Django-Channels 2 you can write custom authentication middleware
https://gist.github.com/rluts/22e05ed8f53f97bdd02eafdf38f3d60a
token_auth.py:
from channels.auth import AuthMiddlewareStack
from rest_framework.authtoken.models import Token
from django.contrib.auth.models import AnonymousUser
class TokenAuthMiddleware:
"""
Token authorization middleware for Django Channels 2
"""
def __init__(self, inner):
self.inner = inner
def __call__(self, scope):
headers = dict(scope['headers'])
if b'authorization' in headers:
try:
token_name, token_key = headers[b'authorization'].decode().split()
if token_name == 'Token':
token = Token.objects.get(key=token_key)
scope['user'] = token.user
except Token.DoesNotExist:
scope['user'] = AnonymousUser()
return self.inner(scope)
TokenAuthMiddlewareStack = lambda inner: TokenAuthMiddleware(AuthMiddlewareStack(inner))
routing.py:
from django.urls import path
from channels.http import AsgiHandler
from channels.routing import ProtocolTypeRouter, URLRouter
from channels.auth import AuthMiddlewareStack
from yourapp.consumers import SocketCostumer
from yourapp.token_auth import TokenAuthMiddlewareStack
application = ProtocolTypeRouter({
"websocket": TokenAuthMiddlewareStack(
URLRouter([
path("socket/", SocketCostumer),
]),
),
})
If you are using Django Channels 3 you can use this code:
https://gist.github.com/AliRn76/1fb99688315bedb2bf32fc4af0e50157
middleware.py
from django.contrib.auth.models import AnonymousUser
from rest_framework.authtoken.models import Token
from channels.db import database_sync_to_async
from channels.middleware import BaseMiddleware
#database_sync_to_async
def get_user(token_key):
try:
token = Token.objects.get(key=token_key)
return token.user
except Token.DoesNotExist:
return AnonymousUser()
class TokenAuthMiddleware(BaseMiddleware):
def __init__(self, inner):
super().__init__(inner)
async def __call__(self, scope, receive, send):
try:
token_key = (dict((x.split('=') for x in scope['query_string'].decode().split("&")))).get('token', None)
except ValueError:
token_key = None
scope['user'] = AnonymousUser() if token_key is None else await get_user(token_key)
return await super().__call__(scope, receive, send)
routing.py
from channels.security.websocket import AllowedHostsOriginValidator
from channels.routing import ProtocolTypeRouter, URLRouter
from .middleware import TokenAuthMiddleware
from main.consumers import MainConsumer
from django.conf.urls import url
application = ProtocolTypeRouter({
'websocket': AllowedHostsOriginValidator(
TokenAuthMiddleware(
URLRouter(
[
url(r"^main/$", MainConsumer.as_asgi()),
]
)
)
)
})
This answer is valid for channels 1.
You can find all information in this github issue:
https://github.com/django/channels/issues/510#issuecomment-288677354
I will summarise the discussion here.
copy this mixin into your project:
https://gist.github.com/leonardoo/9574251b3c7eefccd84fc38905110ce4
apply the decorator to ws_connect
the token is received in the app via an earlier authentication request to the /auth-token view in django-rest-framework. We use a querystring to send the token back to django-channels. If you're not using django-rest-framework you can consume the querystring in your own way. Read the mixin for how to get to it.
After using the mixin, and the correct token is used with the upgrade / connect request, the message will have a user like in the example below.
As you can see, we have has_permission() implemented on the User model, so it can just check its instance. If there is no token or the token is invalid, there will be no user on the message.
# get_group, get_group_category and get_id are specific to the way we named
# things in our implementation but I've included them for completeness.
# We use the URL `wss://www.website.com/ws/app_1234?token=3a5s4er34srd32`
def get_group(message):
return message.content['path'].strip('/').replace('ws/', '', 1)
def get_group_category(group):
partition = group.rpartition('_')
if partition[0]:
return partition[0]
else:
return group
def get_id(group):
return group.rpartition('_')[2]
def accept_connection(message, group):
message.reply_channel.send({'accept': True})
Group(group).add(message.reply_channel)
# here in connect_app we access the user on message
# that has been set by #rest_token_user
def connect_app(message, group):
if message.user.has_permission(pk=get_id(group)):
accept_connection(message, group)
#rest_token_user
def ws_connect(message):
group = get_group(message) # returns 'app_1234'
category = get_group_category(group) # returns 'app'
if category == 'app':
connect_app(message, group)
# sends the message contents to everyone in the same group
def ws_message(message):
Group(get_group(message)).send({'text': message.content['text']})
# removes this connection from its group. In this setup a
# connection wil only ever have one group.
def ws_disconnect(message):
Group(get_group(message)).discard(message.reply_channel)
thanks to github user leonardoo for sharing his mixin.
The following Django-Channels 2 middleware authenticates JWTs generated
by djangorestframework-jwt .
The token can be set via the djangorestframework-jwt http APIs, and it will also be sent for WebSocket connections if JWT_AUTH_COOKIE is defined.
settings.py
JWT_AUTH = {
'JWT_AUTH_COOKIE': 'JWT', # the cookie will also be sent on WebSocket connections
}
routing.py:
from channels.routing import ProtocolTypeRouter, URLRouter
from django.urls import path
from json_token_auth import JsonTokenAuthMiddlewareStack
from yourapp.consumers import SocketCostumer
application = ProtocolTypeRouter({
"websocket": JsonTokenAuthMiddlewareStack(
URLRouter([
path("socket/", SocketCostumer),
]),
),
})
json_token_auth.py
from http import cookies
from channels.auth import AuthMiddlewareStack
from django.contrib.auth.models import AnonymousUser
from django.db import close_old_connections
from rest_framework_jwt.authentication import BaseJSONWebTokenAuthentication
class JsonWebTokenAuthenticationFromScope(BaseJSONWebTokenAuthentication):
"""
Extracts the JWT from a channel scope (instead of an http request)
"""
def get_jwt_value(self, scope):
try:
cookie = next(x for x in scope['headers'] if x[0].decode('utf-8') == 'cookie')[1].decode('utf-8')
return cookies.SimpleCookie(cookie)['JWT'].value
except:
return None
class JsonTokenAuthMiddleware(BaseJSONWebTokenAuthentication):
"""
Token authorization middleware for Django Channels 2
"""
def __init__(self, inner):
self.inner = inner
def __call__(self, scope):
try:
# Close old database connections to prevent usage of timed out connections
close_old_connections()
user, jwt_value = JsonWebTokenAuthenticationFromScope().authenticate(scope)
scope['user'] = user
except:
scope['user'] = AnonymousUser()
return self.inner(scope)
def JsonTokenAuthMiddlewareStack(inner):
return JsonTokenAuthMiddleware(AuthMiddlewareStack(inner))
I believe sending token in query string can expose token even inside HTTPS protocols. To come around such issue I have used the following steps:
Create a token based REST API endpoint which creates temporary session and respond back with this session_key (This session is set to expire in 2 minutes)
login(request,request.user)#Create session with this user
request.session.set_expiry(2*60)#Make this session expire in 2Mins
return Response({'session_key':request.session.session_key})
Use this session_key in query parameter in channels parameter
I understand there is one extra API call but I believe it's much more secure than sending token in URL string.
Edit: This is just another approach to this problem, as discussed in comments, get parameters are exposed only in urls of http protocols, which should be avoided in anyhow.
from rest_framework_simplejwt.tokens import UntypedToken
from rest_framework_simplejwt.exceptions import InvalidToken, TokenError
from jwt import decode as jwt_decode
from urllib.parse import parse_qs
from django.contrib.auth import get_user_model
from channels.db import database_sync_to_async
from django.conf import settings
#database_sync_to_async
def get_user(user_id):
User = get_user_model()
try:
return User.objects.get(id=user_id)
except User.DoesNotExist:
return 'AnonymousUser'
class TokenAuthMiddleware:
def __init__(self, app):
# Store the ASGI application we were passed
self.app = app
async def __call__(self, scope, receive, send):
# Look up user from query string (you should also do things like
# checking if it is a valid user ID, or if scope["user"] is already
# populated).
token = parse_qs(scope["query_string"].decode("utf8"))["token"][0]
print(token)
try:
# This will automatically validate the token and raise an error if token is invalid
is_valid = UntypedToken(token)
except (InvalidToken, TokenError) as e:
# Token is invalid
print(e)
return None
else:
# Then token is valid, decode it
decoded_data = jwt_decode(token, settings.SECRET_KEY, algorithms=["HS256"])
print(decoded_data)
scope['user'] = await get_user(int(decoded_data.get('user_id', None)))
# Return the inner application directly and let it run everything else
return await self.app(scope, receive, send)
Asgi like this
import os
from channels.auth import AuthMiddlewareStack
from channels.routing import ProtocolTypeRouter, URLRouter
from django.core.asgi import get_asgi_application
from django.urls import path
from channelsAPI.routing import websocket_urlpatterns
from channelsAPI.token_auth import TokenAuthMiddleware
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'VirtualCurruncy.settings')
application = ProtocolTypeRouter({
"http": get_asgi_application(),
"websocket": TokenAuthMiddleware(
URLRouter([
path("virtualcoin/", websocket_urlpatterns),
])
),
})
ovveride custom AuthMiddleware
from urllib.parse import parse_qs
from channels.auth import AuthMiddleware
from channels.db import database_sync_to_async
from channels.sessions import CookieMiddleware, SessionMiddleware
from rest_framework.authtoken.models import Token
from django.contrib.auth.models import AnonymousUser
#database_sync_to_async
def get_user(scope):
query_string = parse_qs(scope['query_string'].decode())
token = query_string.get('token')
if not token:
return AnonymousUser()
try:
user = Token.objects.get(key=token[0]).user
except Exception as exception:
return AnonymousUser()
if not user.is_active:
return AnonymousUser()
return user
class TokenAuthMiddleware(AuthMiddleware):
async def resolve_scope(self, scope):
scope['user']._wrapped = await get_user(scope)
def TokenAuthMiddlewareStack(inner):
return CookieMiddleware(SessionMiddleware(TokenAuthMiddleware(inner)))
import the TokenAuthMiddlewareStack middleware in asgi.py
import os
from channels.auth import AuthMiddlewareStack
from channels.routing import ProtocolTypeRouter, URLRouter
from channels.security.websocket import AllowedHostsOriginValidator
from django.core.asgi import get_asgi_application
from chat.api.router_ws import urlpatterns_websocket
from .middleware import TokenAuthMiddlewareStack
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "mysite.settings")
# Initialize Django ASGI application early to ensure the AppRegistry
# is populated before importing code that may import ORM models.
application = ProtocolTypeRouter({
"http": get_asgi_application(),
"websocket": AllowedHostsOriginValidator(
TokenAuthMiddlewareStack(
URLRouter(urlpatterns_websocket)
)
),
})
In frontend:new WebSocket(ws://8000/{your_path}?token=${localStorage.getItem('token')})
In Consumer: you can access the requested user as self.scope["user"]
Regarding Channels 1.x
As already pointed out here the mixin by leonardoo is the easiest way:
https://gist.github.com/leonardoo/9574251b3c7eefccd84fc38905110ce4
I think, however, it is somewhat confusing to figure out what the mixin is doing and what not, so I will try to make that clear:
When looking for a way to access message.user using the native django channels decorators you would have to implement it like this:
#channel_session_user_from_http
def ws_connect(message):
print(message.user)
pass
#channel_session_user
def ws_receive(message):
print(message.user)
pass
#channel_session_user
def ws_disconnect(message):
print(message.user)
pass
Channels does that by authenticating the user, creating a http_session and then converting the http_session in a channel_session, which uses the reply channel instead of cookies to identify the client.
All this is done in channel_session_user_from_http.
Have a look at the channels source code for more detail:
https://github.com/django/channels/blob/1.x/channels/sessions.py
leonardoo's decorator rest_token_user does, however, not create a channel session it simply stores the user in the message object in ws_connect. As the token is not sent again in ws_receive and the message object is not available either, in order to get the user in ws_receive and ws_disconnect as well, you would have to store it in the session yourself.
This would be a easy way to do this:
#rest_token_user #Set message.user
#channel_session #Create a channel session
def ws_connect(message):
message.channel_session['userId'] = message.user.id
message.channel_session.save()
pass
#channel_session
def ws_receive(message):
message.user = User.objects.get(id = message.channel_session['userId'])
pass
#channel_session
def ws_disconnect(message):
message.user = User.objects.get(id = message.channel_session['userId'])
pass
I implemented custom authentication, as described in docs
# custom_permissions.py
from rest_framework import authentication
from rest_framework import exceptions
class KeyAuthentication(authentication.BaseAuthentication):
def authenticate(self, request):
key = request.META.get('Authorization')
print(key)
if not key:
raise exceptions.AuthenticationFailed('Authentication failed.')
try:
key = ApiKey.objects.get(key=key)
except ApiKey.DoesNotExist:
raise exceptions.AuthenticationFailed('Authentication failed.')
return (key, None)
In my settings:
# settings.py
REST_FRAMEWORK = {
'DEFAULT_AUTHENTICATION_CLASSES': (
'api_server.apps.api_v1.custom_permissions.KeyAuthentication',
),
'DEFAULT_PERMISSION_CLASSES': (
'rest_framework.permissions.AllowAny',
),
}
It works as expected during tests:
def test_1(self):
client = APIClient()
client.credentials(X_SECRET_KEY='INVALID_KEY')
response = client.get('/v1/resource/')
self.assertEqual(response.status_code, 403)
self.assertEqual(response.data, {'detail': 'Authentication failed.'})
def test_2(self):
client = APIClient()
client.credentials(X_SECRET_KEY='FEJ5UI')
response = client.get('/v1/resource/')
self.assertEqual(response.status_code, 200)
However when I test with curl and locally running server, there is no X_SECRET_KEY header found in request.META. It is printing None in terminal, while received key is expected.
$ curl -X GET localhost:8080/v1/resource/ -H "X_SECRET_KEY=FEJ5UI"
{'detail': 'Authentication failed.'}
Could you give a hint, what might be a problem with that?
The headers variables are uppercase and prefixed with "HTTP_". This is general to Django, dunno about other languages / frameworks.
See https://github.com/tomchristie/django-rest-framework/blob/master/rest_framework/authentication.py#L23 for example.
I am doing a RESTful web service by CherryPy. Since the client is not always a browser and may not be able to store cookie, so I plan to get CherryPy's session id and pass it via HTTP GET/POST as a token. When client send request with this token(session id) to CherryPy it could restore session just like what cookie does and the server side can get authentication or any stateful data.
My question is, how to restore the CherryPy session by specific id?
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import cherrypy.lib
config = {
'global' : {
'server.socket_host' : '127.0.0.1',
'server.socket_port' : 8080,
'server.thread_pool' : 4
}
}
class App:
#cherrypy.expose
#cherrypy.config(**{'tools.sessions.on': True})
def counter(self):
if 'counter' not in cherrypy.session:
cherrypy.session['counter'] = 0
cherrypy.session['counter'] += 1
return 'Counter: {0}<br/>Session key: {1}'.format(
cherrypy.session['counter'],
cherrypy.request.cookie['session_id'].value
)
#cherrypy.expose
def recreate(self, token):
'''You can try open it from another browser
once set the value in /counter
'''
cherrypy.request.cookie['session_id'] = token
cherrypy.lib.sessions.init()
# now it should be ready
return 'Counter: {0}'.format(cherrypy.session['counter'])
if __name__ == '__main__':
cherrypy.quickstart(App(), '/', config)
Inspired by saaj I found a solution that works. Try this...
import cherrypy.lib
config = {
'global' : {
'server.socket_host' : '127.0.0.1',
'server.socket_port' : 8080,
'server.thread_pool' : 4,
'tools.sessions.on': True,
'tools.sessions.storage_type': "file",
'tools.sessions.storage_path': "adf"
}
}
class Helloworld:
#cherrypy.expose
def make(self, token=''):
'''You can try open it from another browser
once set the value in /counter
'''
if(token == ''):
cherrypy.lib.sessions.init()
# take this token and put in the url 127.0.0.1:8080/make/ + token
return cherrypy.session.id
else:
#send two requests with the token. 1. to set a session var
# and 2. to retrieve the var from session
cherrypy.lib.sessions.init(self, id=token)
print('do something')
# on the second request check the value after init and it's HI!
cherrypy.session['something'] = 'HI'
return token
if __name__ == '__main__':
cherrypy.quickstart(Helloworld(), '/', config)
Hope this helps!
The previous examples didn't work for me (at least for file sessions). Maybe because the current version of cherrypy forbids session init for already initialized sessions. What did work, however, is this:
cherrypy.session.id = token
cherrypy.session._load()
I understand this is dirty, since the private method is called, but it's the only way I found.