Make Flask's url_for use the 'https' scheme in an AWS load balancer without messing with SSLify

Question

I\'ve recently added a SSL certificate to my webapp. It\'s deployed on Amazon Web Services uses load balancers. The load balancers work as reverse proxies, handling external

Answer 1

I was having these same issues with `redirect(url_for('URL'))' behind an AWS Elastic Load Balancer recently & I solved it this using the werkzeug.contrib.fixers.ProxyFix call in my code. example:

from werkzeug.contrib.fixers import ProxyFix
app = Flask(__name__)

app.wsgi_app = ProxyFix(app.wsgi_app)

The ProxyFix(app.wsgi_app) adds HTTP proxy support to an application that was not designed with HTTP proxies in mind. It sets REMOTE_ADDR, HTTP_HOST from X-Forwarded headers.

Example:

from werkzeug.middleware.proxy_fix import ProxyFix
# App is behind one proxy that sets the -For and -Host headers.
app = ProxyFix(app, x_for=1, x_host=1)