How to dynamically add EC2 ip addresses to Django ALLOWED_HOSTS

Question

We\'ve recently changed our deployment strategy to use AWS auto scaling group.

One problem we have in production is with the newly created EC2s.
Our Application sta

Answer 1

You can retrieve an EC2 instance Meta data by making an API request to

curl http://169.254.169.254/latest/meta-data/
GET http://169.254.169.254/latest/meta-data/

source

And you can get just the private IP for a specific instance by making an API call:

GET http://169.254.169.254/latest/meta-data/local-ipv4

So in your Django settings file add this script to "dynamically" add IPs to your allowed hosts:

import requests
EC2_PRIVATE_IP = None
try:
    EC2_PRIVATE_IP = requests.get(
        'http://169.254.169.254/latest/meta-data/local-ipv4',
        timeout=0.01).text
except requests.exceptions.RequestException:
    pass

if EC2_PRIVATE_IP:
    ALLOWED_HOSTS.append(EC2_PRIVATE_IP)