Flask Blueprint : how to run each apps in different port? - flask

I got a flask application with different apps inside, using BluePrint.
To simplify, I got an API that manages token web authentification (and a lot of other data functions) and a website that should call the API to get the valid token, using a basic auth to start with
The issue is that when the website requests the API, it never gets any feedback from the API.
Requesting the API via POSTMAN works like a charm, but this call below, done from a website route is waiting, waiting, waiting and never ends.
So my assumption is that using the same port for both website and api is the issue
I could of course divides the flask into 2 flask apps with 2 servers, but there are many objects and tools both API and website are sharing, so I dont want to double the job
Thanks.
call from the website
from requests.auth import HTTPBasicAuth
import requests
mod = Blueprint('site', __name__, template_folder='templates/login')
def load_user(username, password):
data = requests.get('http://127.0.0.1:5000/api/login',
auth=HTTPBasicAuth('username', 'password'))
return data
#mod.route('/')
def index():
username = 'jeje'
password = 'jeje'
data = load_user(username, password)
return '<h1>load user<h1>'
the api function
#mod.route('/login')
def login():
resu = True
auth = request.authorization
if not auth or not auth.username or not auth.password:
resu = False
user = USER.query.filter_by(username = auth.username).first()
if not user:
resu = False
if validehash(user.password, auth.password):
period_in_mn = 120
payload = {
'public_id':user.public_id,
'exp' : datetime.datetime.utcnow() + datetime.timedelta(minutes = period_in_mn)
}
token = createtoken(payload, current_app.config['SECRET_KEY'])
if resu:
return jsonify({'token' : token })
else:
return jsonify({'token' : 'unknown'})

I guess your using flask 0.12 instead of 1.0. So whats happening here is that you're requesting a route from within another route.
Your browser requests /, and in your index function, you request /login. But the flask process is still working on the / request from the browser, and can't take any other requests, because flask 0.12 is working on a single core only.
Requesting like this is bad design. You could make a helper function, which returns the same data in different requests (either api or main site), or you could make the browser send another request using AJAX.
Flask 1.0 has multicore support, so I think this might work over there, but I really think you should change your design. This has absolutely nothing to do with blueprints by the way.
from flask import Flask, redirect
import requests
app = Flask(__name__)
#app.route('/')
def index():
result = requests.get('http://127.0.0.1:5000/api/login')
return 'this is the index<br>' + result.text
#app.route('/api/login')
def login():
return 'you are logged in'
Using flask 0.12, times out when visiting http://127.0.0.1:5000/.
Using flask 1.0, returns this is the index
you are logged in when visiting http://127.0.0.1:5000/.

Related

CSRF invalid token for API call in Flask

My objective is to build Rest API on Flask. When i send post JSON request to the server from Postman application http://127.0.0.1:5000/api/v1/posts/add/post, I get "The CSRF token is missing" Error.
Respective route is here:
#api.route('/posts/add/post', methods=['POST'])
def add_post():
subject = request.json['subject']
body = request.json['body']
myPost = Post(subject=subject, body=body, category_id=1)
db.session.add(myPost)
db.session.commit()
return post_schema.jsonify(myPost).data
I have looked at different examples and nobody mentions about CSRF for such requests, as usually its used for WTF s.
Can you please advice, what am i doing wrong and fow to fix it?
Based on this extract from the docs, is it possible you are protecting your app like this?
from flask_wtf.csrf import CSRFProtect
csrf = CSRFProtect(app)
Usually, you only need this for basic flask apps (docs):
from flask import Flask
app = Flask(__name__)

How to use dj-rest-auth with many clients

I'd like to have many different clients be able to access my django website (more specifically its API) but I'm not sure how to do this with django-allauth, dj-rest-auth and simplejwt.
My current client app is using the built in django template engine and is set up with django-allauth for social authentication (Google etc). It's working using the documented installation recommendations.
I would now like to create different types of clients that aren't using the django template engine (e.g. Angular, Vue, flutter mobile etc) but I'm confused how dj-rest-auth is used so that it scales to support any number of client types.
Using Google social sign in as an example, when I create a new client, I have to register a new redirect_uri specific to that client.
To test this all out, I created a simple flask app with a single link so that I can retrieve a "code/access_token" before sending it to my Django app. The link is created using the following...
var codeRequestUrl =
`https://accounts.google.com/o/oauth2/v2/auth?\
scope=email&\
access_type=offline&\
include_granted_scopes=true&\
response_type=code&\
state=state_parameter_passthrough_value&\
redirect_uri=http%3A//127.0.0.1:5000/callback&\
client_id=${clientId}`;
...and the code is retrieved at the '/callback' endpoint in flask...
#app.route("/callback", methods=['GET'])
def redirect():
code = request.args.get('code', '')
req = requests.post('http://127.0.0.1:8000/api/dj-rest-auth/google/', data={'code':code})
return "done..."
...from where I send an x-www-form-urlencoded POST request back to a dj-rest-auth endpoint that is set up as per its documentation...
class GoogleLogin(SocialLoginView):
callback_url = 'http://127.0.0.1:5000/callback'
adapter_class = GoogleOAuth2Adapter
client_class = OAuth2Client
...
urlpatterns += [
...
path('dj-rest-auth/google/', GoogleLogin.as_view(), name='google_login'),
....
]
Django then successfully returns an access_token, refresh_token and some info about the logged in user.
But this isn't something that scales well. If I were to also create an Angular client, I'd need to register a different callback (because the Angular client would be running on a different port and/or address, and I'd also need another path set up in urls.py and associate it with a new SocialLoginView subclass that can handle the different callback_url (redirect_uri).
And with all this in mind, I have no idea how to do all of this with a flutter mobile app, which as far as I'm aware, has no concept of a callback_url, so I'm not sure how making a POST request to .../dj-rest-auth/google/ would even work given that I'd instantly get a redirect_uri_mismatch error.
Have I got it backwards and the client registered at Google is the Angular, Vue, Flash etc app? That would mean that each client would have to handle its own client_id and client_secret, which then seems to bypass django-allauth's and dj-rest-auth's functionality.
I feel like I'm misinterpreting this, so I would really appreciate some suggestions.
I feel confident enough to answer my own question.
In short, yes, multiple clients (including thirdparty) is a reasonably straight forward process. Unfortunately a lot of the blog posts and tutorials that exist take the perspective of a 'second party' client, which really confuses things. The result is a lot of error messages relating to the redirect_uri.
To their credit, the Google docs for their example Flask app was exactly what I needed, but there are a couple of observations that are really important, and what caused so much confusion for me.
First, and most important, the callback (redirect_uri) is not needed in Django at all. In Django, something like this is all that is required.
from allauth.socialaccount.providers.oauth2.client import OAuth2Client
from allauth.socialaccount.providers.google.views import GoogleOAuth2Adapter
class GoogleLogin(SocialLoginView):
adapter_class = GoogleOAuth2Adapter
client_class = OAuth2Client
urlpatterns += [
...
path('auth/google/', GoogleLogin.as_view(), name='google_login'),
...
]
So no callback attribute is required. The reason for this is that the Flask (or thirdparty app) handles all of the Google side authentication.
The second observation was that the redirect_uri in the Flask app seemed have have to be the same for both the "code" request step, and the "access_token" step.
You can see it in the linked example where the oauth2callback function (which handles the redirect_uri), but I've modified for use with dj-rest-auth
#app.route('/')
def index():
if 'credentials' not in flask.session:
return flask.redirect(flask.url_for('oauth2callback'))
credentials = json.loads(flask.session['credentials'])
if credentials['expires_in'] <= 0:
return flask.redirect(flask.url_for('oauth2callback'))
else:
data = {'access_token': credentials['access_token']}
headers = headers = {'Content-Type': 'application/x-www-form-urlencoded'}
r = requests.post(f'{URL_ROOT}/api/auth/google/', data=data, headers=headers)
response_json = json.loads(r.text)
access_token = response_json['access_token'] # JWT Access Token
refresh_token = response_json['refresh_token']
# Make a query to your Django website
headers = headers = {'Authorization': f'Bearer {access_token}'}
r = requests.post(f'{URL_ROOT}/api/object/{OBJECT_ID}/action/', data=data, headers=headers)
# do stuff with r
#app.route('/oauth2callback')
def oauth2callback():
if 'code' not in flask.request.args:
auth_uri = ('https://accounts.google.com/o/oauth2/v2/auth?response_type=code'
'&client_id={}&redirect_uri={}&scope={}').format(CLIENT_ID, REDIRECT_URI, SCOPE)
return flask.redirect(auth_uri)
else:
auth_code = flask.request.args.get('code')
data = {'code': auth_code,
'client_id': CLIENT_ID,
'client_secret': CLIENT_SECRET,
'redirect_uri': REDIRECT_URI,
'grant_type': 'authorization_code'}
r = requests.post('https://oauth2.googleapis.com/token', data=data)
flask.session['credentials'] = r.text # This has the access_token
return flask.redirect(flask.url_for('index'))
So in summary, it's a bit like this:
On the index/home page, the user presses a "Login" html anchor that points to /login.
Flask doesnt have any credentials, so redirects to /oauth2callback to begin authentication.
First, the "code" is retrieved using Googles' GET /auth endpoint, and by using your app's client id.
The redirect_uri ensures the code flow goes back to itself, but this time, with the "code" now know, do a POST request to Google's /token endpoint using your apps's client id and client secret. Again, the redirect_uri is the same (/oauth2callback).
Now that Googles's access_token is known, the Flask app redirects back to /index (although it could be anywhere at this point)
Back in /index, the Flask app now has Google's "access_token". Use that to log into Django's dj-rest-auth endpoint that you created.
Django will then return its own access_token and refresh_token, so continue to use those as needed.
I hope this helps.
Note that your flask app will need to be registered as a new Web App with Google's OAuth2 console (so it has it's own client id and client secret). In other words, don't reuse what you may have already created with an existing Django allauth implementation (which was my scenario). Each thirdparty app maker will handle their own OAuth2 credentials.

Flask Security to API without db at backend

I am new to Stack overflow. I developed an API using Flask but I want to add security to it so that only those who has some key can run it. No database at backend, any token based or other latest secure way of running the API?
For eg: app.route('/test') if I run it using local_host/test then it triggered, the same way no one from the team who has the same access should not run that easily until and unless I(Producer) provide some key to Consumer and Consumer uses that key to connect my API.
The best way to do this is with basic authentication. This means that every time someone makes a request to your endpoint, they need to supply a username and password in the header with the request.
A great minimal example is located here: https://flask-httpauth.readthedocs.io/en/latest/
from flask_httpauth import HTTPBasicAuth
app = Flask(__name__)
auth = HTTPBasicAuth()
#auth.verify_password
def verify_password(username, password):
if username == 'approved_username' and password == 'correct-password':
return True
return False
#app.route('/')
#auth.login_required
def index():
return "Hello, %s!" % auth.username()
if __name__ == '__main__':
app.run()
I've modified it slightly to make it even more simple by removing the dynamic user lookup.
To use this, you just need to add the auth.login_required decorator to any route you wish to protect.

How to implement GUI Less Oauth Authentication system to access API's built using Python-Flask

I have written a simple Python Flask API which does operations like adding data to Database and getting data from Database, there is no UI for this API, Now I want to implement OAuth authentication system for this simple API, As there is NO GUI, I cant use google or FB Oauth Providers which redirects users to there login page.
In simple words, i want to create my own GUI less oauth Authentication system which secures my API as any user who wants to access my API should pass through this authentication system by passing access token in a header
I need Oauth Authentication system of my own for the API's below:
from flask import Flask, redirect, url_for, session
from flask import Flask,jsonify,request,make_response
from flask_login import login_user,logout_user,current_user,login_required,LoginManager,login_manager
from flask_oauth import OAuth
import json
from flask_mysqldb import MySQL
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_oauthlib.provider import OAuth1Provider
app = Flask(__name__)
class MYWIFI(db.Model):
__tablename__ = 'MYWIFI'
id = db.Column('id', db.Integer, primary_key=True)
data = db.Column('data', db.Unicode)
def __init__(self, id, data):
self.id = id
self.data = data
#app.route('/getall')
def getall():
access_token = get_access_token()
if access_token is None:
return redirect(url_for('login'))
else:
languages = [u.__dict__ for u in db.session.query(MYWIFI).all()]
for d in languages:
del d['_sa_instance_state']
print(languages)
languagesJSON = json.dumps(languages)
return languagesJSON
#app.route('/insert', methods=['GET','POST'])
def insert():
access_token = get_access_token()
if access_token is None:
return redirect(url_for('login'))
else:
if request.method == 'POST':
insert = request.get_json()
id = insert['id']
data = insert['data']
print id
print data
new = MYWIFI(id, data)
db.session.add(new)
db.session.commit()
return "Success"
def main():
app.run()
if __name__ == '__main__':
main()
Please can anyone help me in kick starting this
I appreciate for this help
If I understood correctly, what you want is to build API endpoints which are protected by OAuth 2.0 tokens. If that's the case you as the API builder does not have to worry how token obtaining process happens. The client that consumes your APIs must perform the token obtaining and pass them to your end.
About sending in headers, try to stick with standards already exist in the OAuth 2 domain. RFC6750 defines how to use tokens once a client obtains them. It defines bearer authentication schema to transmit access tokens. Check section 2.1 to how header is set.
GET /resource HTTP/1.1
Host: server.example.com
Authorization: Bearer mF_9.B5f-4.1JqM
Where mF_9.B5f-4.1JqM is the access token. Once your API receives a request, from your end you must validate the access token before granting access. For this there is RFC7662 which define the methodology to validate access token against the authorization server. See section 2 Introspection endpoint to get an understanding of it. Alternatively, access token can come in a JWT format thus allowing it to be self contained.
Unfortunately, I do not have code for proposed solutions. They will considerable amount of codes. But I suggest you to separate authorization logic from your code. That means validation of authorization must be a separate module in your python code. But below I give a suggestion with my python knowledge.
#app.route('/insert', methods=['GET','POST'])
def insert():
access_token = get_access_token()
# Auth Validation for insert - This is based on access tokens
# If token is invalid/not-present, exception is thrown with HTTP 401 - unauthorized
my_auth_module.validate_access_token(access_token)
if request.method == 'POST':
insert = request.get_json()
id = insert['id']
Also one final thing, your API should not worry about redirection for login. Let it be handled by your API client upon the 401 - Unathorized response.

Flask-appbuilder RESTful API vs Flask-RESTful API

I am trying to use Flask-appbuilder in an IoT project. So, FAB is used for rapid application buildup and we need dedicated RESTful API for Mobile App and 3rd party service suppliers.
In FAB, there is an implementation for RESTful API, as subclass of BaseCURDView. Most URL is defined as
http://host//api/list
If the mobile app acts as an user agent like browser, it collect username/password, login and access FAB's RESTful API, then permissions, url is not a big deal, everything can follow B/S programming. AKA, all security model is based upon cookie and session. Most of the request information are inside the flask.g.user/flask.request.*.
If the webapp has to support more standard style RESTful API, as described in flask books by miguel. The external webapp has to embed the api key/secret to specified url to exchange token, then use token in header or http parameters to access resources for CRUD operations.
http://host/api/v1/get_token
header:api_key:balabalabala
header:api_secret:abcdefxyz
return {'token':'1234567890'}
http://host/api/v1/resource
header:token:1234567890
return {'resource':'abcdefghijk'}
I have successfully merged them together in FAB's views.py.
from flask import render_template
from flask_appbuilder.models.sqla.interface import SQLAInterface
from flask_appbuilder import ModelView, BaseView, expose
from app import appbuilder, db
from flask import Flask, jsonify
from flask import abort
from flask import make_response
from flask import request
from flask import url_for
tasks = [
{
'id': 1,
'title': u'Buy groceries',
'description': u'Milk, Cheese, Pizza, Fruit, Tylenol',
'done': False
},
{
'id': 2,
'title': u'Learn Python',
'description': u'Need to find a good python tutorial',
'done': False
}
]
def make_public_task(task):
new_task = {}
for field in task:
if field == 'id':
new_task['uri'] = url_for('get_task', task_id=task['id'], _external=True)
else:
new_task[field] = task[field]
return new_task
class ApiView(BaseView):
route_base = "/api/v1"
default_view = "index"
#expose("/index")
def index(self):
#return jsonify({'tasks': map(make_public_task, tasks)})
print repr(request.args)
print repr(request.method)
print repr(request.headers)
return jsonify(tasks)
#expose("/get_token")
def get_token(self):
print repr(request.headers)
return jsonify({'res': True})
#expose("/get_resource")
def get_resource(self):
return jsonify({'res': False})
#expose("/del_resource")
def del_resource(self):
return jsonify({'res': False})
"""
Application wide 404 error handler
"""
#appbuilder.app.errorhandler(404)
def page_not_found(e):
return render_template('404.html', base_template=appbuilder.base_template, appbuilder=appbuilder), 404
db.create_all()
appbuilder.add_view_no_menu(ApiView())
Yes, I can implement standard RESTful API just I did in another flask project with http headers and custom queries with sqlalchemy. But I am not sure if it is the proper way to do that. Since most of the data are requested directly from sqlalchemy raw queries, they are quite different programming experiences.
Open for any suggestions, before moving forward.
Actually FAB's REST API is designed for AJAX, so for mobile app and 3rd party applications, we need a seperate RESTful API, which can follow flask megatutorial and best practice and resue REST-auth library from Miguel.
FAB can work with both anyway.