A very efficient and simple Django middleware to obtain the real IP address from the headers sent by a trusted load balancer
Behind-LB is a very simple and efficient Django middleware to obtain the client IP address when the project runs behind a trusted load balancer.
It allows to specify the path that activate the middleware, for example / or /a/specific/path. The path must be specified in the variable BEHIND_LB_PATH in your settings.py.
It works with any load balancer that sends the public remote address in a fixed relative position in the header (first, second,… , last). For example, Amazon ELB puts it in the last position, Google Compute Load Balancer in the penultimate one. The position must be specified in settings.BEHIND_LB_POSITION.
Install the package:
pip install django-behind-lb
Just add django-behind-lb to your INSTALLED_APPS setting like this:
MIDDLEWARE_CLASSES = ( 'behind_lb.middleware.BehindLB', ...
Configure the path and position in settings.py:
BEHIND_LB_PATH = "/" BEHIND_LB_POSITION = -2 # For Google Compute Engine
Try it reading the default request.META['REMOTE_ADDR'] in a View class. It should read the real client IP.
The BEHIND_LB_PATH value specifies the position of the real IP address in the X-Forwarded-For header, where 0 is the first (or “left”), 1 the second, -2 the penultimate position and -1 the last one. Examples:
BEHIND_LB_POSITION = 0 # First BEHIND_LB_POSITION = -2 # Next to last, for Google Compute Engine LB BEHIND_LB_POSITION = -1 # Last, for Amazon EC2 LB
The code is available at https://github.com/APSL/django-behind-lb
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