Get the URL of a server - python

I am using flask and flask email for sending an email. When I work on I used the localhost as a base url. I deployed it on the server and email sent is still showing with localhost address.
For example
base_url = "http://localhost:0.0.0.6465"
url=base_url+'/login'
I sent an email(i am using flask-mail) with the url and I can login with the url.
With the same script when I deployed on the server I am getting with same localhost address.I need the server URL should be the base url.
To debug this I tried
url=request.base_url+'/login'
I am getting 404 error in the browser if I use this. I dont want to change the initializtion of base_url because I have to use both in the local as well as in the server.
How can I do that?

You can get the URL to the currently running app through request.host_url. But what you really want to to do to get an external URL to a specific part of your application, is to use url_for as you'd do when referencing your regular endpoints, but with the parameter _external=True:
Given that you have:
#app.route('/login')
def login():
....
You can generate an external URL by using:
from flask import (
url_for,
)
...
url = url_for('login', _external=True)
This will also take into account any proxies in front of your application if you need that, as long as you've used the ProxyFix middleware when setting up your app object.
Since this uses the same mechanism as Flask uses when generating URLs between different pages, it should behave just as you want - i.e. it'll work both on localhost and on the remote host.

Related

How to change the Redirect URI from HTTP to HTTPS within a FastAPI web app using fastapi_msal?

I am trying to setup Azure AD authentication for a web application using FastAPI. I am using the fastapi_msal python package to do this. The problem I am having is that when I go to the web app, I am able to login, but once i am authenticated, it says the redirect URI that the application is using begins with HTTP. However, Azure requires the redirect uri begin with HTTPS unless running the app locally. Does anyone know how I can change the redirect uri to begin with https instead?
The code for my project pretty much exactly resembles the code from this example project here. However, I have found a similar project using Flask instead of FastAPI. And there is a specific portion of the code that addresses this redirect uri problem:
# This section is needed for url_for("foo", _external=True) to automatically
# generate http scheme when this sample is running on localhost,
# and to generate https scheme when it is deployed behind reversed proxy.
# See also https://flask.palletsprojects.com/en/1.0.x/deploying/wsgi-standalone/#proxy-setups
from werkzeug.middleware.proxy_fix import ProxyFix
app.wsgi_app = ProxyFix(app.wsgi_app, x_proto=1, x_host=1)
Does anyone know how I can do something like this for a web app using FastAPI instead?
The full source code for the Flask app can be found here

Flask redirect url_for generates Cloud Run service URL instead of domain

Background:
I've built and deployed an app with Google Cloud Firebase. At a high level, I have a Python Flask server running on Cloud Run, and I serve static JS files with Firebase hosting.
Issue:
Sometimes, I want to redirect the user, but I'm sending them to the Cloud Run service URL rather than my app domain.
EDIT: I'm NOT experiencing this in the JS on the browser, but ONLY in the Python on the server.
Python
If a user navigates to a page without being signed in, e.g. following a link, they are redirected to my login page. For example, if someone who is not signed in tries to look at someone else's profile, the following code redirects them to the authentication blueprint's login endpoint:
if not session.get('user'):
return redirect(url_for('authentication.login'))
I would expect them to be redirected to my-app-name.web.app/auth/login but instead they're routed to my-cloudrun-service-name-XXXXX-region.run.app/auth/login. While the pages loaded look the same, they're really not. The second one redirects to the Cloud Run service URL, which doesn't have my static files served by Firebase Hosting.
I'm not really sure, but I believe this happens because Flask is generating the URL using the request context. So the request from the browser hits Cloud Run Load Balancer, which directs the request to my Cloud Run instance, but that means the Flask app in my Cloud Run instance only sees the internal Google Cloud redirect, and it doesn't know my domain.
I've tried solving this by setting app.config['SEVER_NAME'] = my-app-name.web.app, but I just get the "Not Found" page on each request. Is SEVER_NAME the solution but I'm not implementing it correctly, or is there another way to fix the Flask url_for generation?
I've found what I deem to be an effective solution / workaround.
I set the app config to store my BASE_URL when the app is created:
app.config['BASE_URL'] = 'https://my-url.domain'
Then I can access this as application context during requests, even from blueprints:
#blueprint.route('my_route/')
def my_route():
if not session.get('user'):
return redirect(current_app.config['BASE_URL'] + url_for('authentication.login', 302)
This has two key benefits for me:
There's only one place, the app config, to update if I change the domain
url_for is still used, so there's no hardcoding in case blueprints or routes change

How to pass URLs as parameters in a GET request within python flask (restplus)?

I am creating a REST API using python flask. The API is ready and works on port number 8000 of my localhost. Now I intend to give this REST API a user friendly interface for which I decided to go with python - restplus. I thought of calling this service (running on 8000) internally from swagger application running on 5000
I was able to create the basic structure of the API (Swagger). The code for which looks like this:
import flask
from flask import Flask, request
from flask_restplus import Resource, Api
app = Flask(__name__)
api = Api(app)
#api.route('/HybridComparator/<string:url2>/<string:url1>')
class HybridComparator(Resource):
def get(self, url1, url2):
print(url1)
print(url2)
return url1 + ' ' + url2
if __name__ == '__main__':
app.run(debug=True)
The application as a whole runs seamlessly (with random strings as parameters) on port 5000. But when the URLs I pass are actual links, the application returns a response of 404 - Not found. Further to my investigation I realized the culprit being '/' embedded within the links I try to provide. Is there a way to handle URLs in particular?
Should I encode them before sending a request. (This will make my parameters look ugly). Is there something I am missing?
This is an entirely old question and I am sure you solved your problem by now.
But for new searchers, this may come in handy;
replace <string:url2>/<string:url1> with <path:url2>/<path:url1>
it seems that :
#api.route('/HybridComparator/<path:url2>/<path:url1>')
should fix it ,it fixes the 404 but i am getting only "http:/" part of the param

Routes With Custom Domains Using Flask

My web app assigns a subdomain to users and optionally allows them to use a custom domain. This works except when the user visits their custom domain for a route without including a trailing slash.
GET requests to this url works as expected: http://user.example.com:5000/book/12345/
GET requests to this url works as expected: http://custom.com:5000/book/12345/
GET requests to this url attempt to redirect, but fail: http://custom.com:5000/book/12345
Flask ends up redirecting the browser to this url which, of course, doesn't work: http://<invalid>.example.com:5000/book/12345/
Is there a different way that I should handle custom domains? Here's a complete minimal example to reproduce this. I have set custom.com, example.com. and user.example.com to point to 127.0.0.1 in my /etc/hosts file in my development environment so that Flask receives the request.
from flask import Flask
app = Flask(__name__)
server = app.config['SERVER_NAME'] = 'example.com:5000'
#app.route('/', subdomain="<subdomain>")
#app.route('/')
def index(subdomain=None):
return ("index")
#app.route('/book/<book_id>/', subdomain="<subdomain>")
#app.route('/book/<book_id>/')
def posts(post_id, subdomain=None):
return (book_id)
if __name__ == '__main__':
app.run(host='example.com', debug=True)
I'm not sure that's possible. host matching and subdomain matching are mutually exclusive (look at host matching parameter).
I'd love to be wrong though.
One way around this issue that I can think of is to use something in front of Flask (say nginx) that points custom.com to custom.com._custom.example.com or something like that. In your code you could create a custom url_for function that would recognize this as a custom domain. I would ask on the Flask mailing list as they would be able to give you a solid answer.

Empty reply from Django web service

I have created a web service in django and its hosted on a shared server.The django web service respond to request from a game made in unity. But whenever game tries to request a django Web service url the server send empty resonse.Response is always:
WWW Error: server return empty string
The Unity webplayer expects a http served policy file named "crossdomain.xml" to be available on the domain you want to access with the WWW class, (although this is not needed if it is the same domain that is hosting the unity3d file).So I placed a file "crossdomain.xml" at the root of my domain ,but still i am getting same empty reply.Help plz...
EDIT:
I tried it through browser my service works fine and reply with proper response.And you know what My game can communicate to django web service when both are running on local machine.But now the django project is hosted on actual server and when game tried accessing service it never get response :(
url.py
urlpatterns = patterns('',
url(r'^crossdomain.xml$',views.CrossDomain),
url(r'^ReadFile/$',views.ReadFile),
)
views.py
def CrossDomain(request):
f = open(settings.MEDIA_ROOT+'jsondata/crossdomain.xml', 'r')
data = f.read()
f.close()
return HttpResponse(data, mimetype="application/xml")
def ReadFile(request):
f = open(settings.MEDIA_ROOT+'jsondata/some_file.json', 'r')
data = f.read()
f.close()
return HttpResponse(data, mimetype="application/javascript")
def Test(request):
return HttpResponse("Hello", mimetype="text/plain")
As I said using django for this is slight overkill because you could just serve them. Point aside though. If your serving on a different server it could be
A) Connection problems mean that your response is lost
B) Firewall issues mean that the request mean something
C) The server isn't setup correctly and therefore it justs get an error.
You need to test the response on the server. so is you access the page on the server through your browser. If so then make the game make a request and check the server error and access logs. In the apache access log you should see something like
GET "/url" 200 each time a request is made.
If you don't see any request getting through then either the request isn't made or its been lost.
If you do then the problem is in the code somewhere.

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