[FIXED] Redirect HTTP to HTTPS on Flask+Heroku

Issue

When I attempt to redirect incoming traffic to https I get an infinite redirect loop.

@app.route('/checkout/')                                                                                                                                                                                        
def checkout():                                                                                                                                                                                                 
    checkout = "https://myapp.herokuapp.com/checkout/"                                                                                                                                              
    if checkout != request.url:                                                                                                                                                                             
        print checkout, request.url                                                                                                                                                                             
        return redirect(checkout)                                                                                                                                                                               
    return render_template('checkout.html', key=keys['publishable_key']) 

The request.url is never changed to prefix https. I want to use heroku's piggyback ssl to minimize cost.

Solution

On Heroku, SSL (https) is terminated before it reaches your application, so you app never actually sees SSL traffic. To check whether a request was made with https, you instead have to inspect the x-forwarded-proto header. More info here: How to make python on Heroku https only?

UPDATE: For your use, you should just check request.url for "myapp.herokuapp.com/checkout/"; and verify that the header is "https"

Answered By - friism