How do I get the IP address of a visitor in Flask?
The IP address associated with the current request is stored in the Flask Request
object’s remote_addr
attribute. The following simple application will display the IP address of visitors to the /whatsmyip
route:
from flask import Flask, request app = Flask(__name__) @app.route("/whatsmyip", methods=["GET"]) def whats_my_ip(): return request.remote_addr app.run()
However, this will only work if users connect directly to your Flask web server. If it’s running behind a proxy such as NGINX, as is often the case in production environments, remote_addr
will always be the local loopback address, 127.0.0.1
. From Flask’s perspective, all requests are coming from the proxy.
Fortunately, we can fix this by including some additional code to tell Flask it is behind a proxy. This code will configure our application to assign request.remote_addr
from the request’s X-Forwarded-For
HTTP header.
from werkzeug.middleware.proxy_fix import ProxyFix app.wsgi_app = ProxyFix( app.wsgi_app, x_for=1, x_proto=1, x_host=1, x_prefix=1 )
ProxyFix
must be called with the exact number of proxies that are in front of the Flask server, or malicious users will be able to spoof their IP addresses by including their own X-Forwarded-For
header in their requests.
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