I believe that the problem you have maybe due to the ALLOWED_HOSTS settings located in your file settings.py.

EB sends an HTTP request to your application to see if its working but Django blocks any communication that is not from the specified hosts in the setting variable. But there is a problem here, EB sends the request to the private ip of the ec2 instance.

The easiest way to solve this is to allow all HOSTS like this inside your settings.py file:

ALLOWED_HOSTS=['*']

This may lead to security issues but is the fastest way to do it. Now, to make it work dynamically, since ec2 instances can be spin-up at any time the private ip change from instance to instance.

To solve this you have to get the private IP at the beginning of the deployment process.

At the top of your settings.py place the following functions:

import os
import requests
# Other imports ...

def is_ec2_linux():
"""Detect if we are running on an EC2 Linux Instance
   See http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/identify_ec2_instances.html
"""
    if os.path.isfile("/sys/hypervisor/uuid"):
        with open("/sys/hypervisor/uuid") as f:
            uuid = f.read()
            return uuid.startswith("ec2")
    return False

def get_token():
"""Set the autorization token to live for 6 hours (maximum)"""
    headers = {
        'X-aws-ec2-metadata-token-ttl-seconds': '21600',
    }
    response = requests.put('http://169.254.169.254/latest/api/token', headers=headers)
    return response.text


def get_linux_ec2_private_ip():
    """Get the private IP Address of the machine if running on an EC2 linux server.
See https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instancedata-data-retrieval.html"""

    if not is_ec2_linux():
        return None
    try:
        token = get_token()
        headers = {
            'X-aws-ec2-metadata-token': f"{token}",
        }
        response = requests.get('http://169.254.169.254/latest/meta-data/local-ipv4', headers=headers)
        return response.text
    except:
        return None
    finally:
        if response:
            response.close()
# Other settings

The most important functions are get_token() and get_linux_ec2_private_ip(), the first one sets the access token and retrieves it for the second one to use it and get the current ec2 instance IP.

Once you have retrieved it, add it to your ALLOWED_HOSTS

ALLOWED_HOSTS = ['127.0.0.1', 'mywebsite.com']
private_ip = get_linux_ec2_private_ip()
if private_ip:
   ALLOWED_HOSTS.append(private_ip)

After that just commit your changes and redeploy it with eb deploy if you have set the EB CLI.

There is a package django-ebhealthcheck that's designed to solve this problem by getting the local ip of your ec2 instance and adding it to ALLOWED_HOSTS, it's very simple to use, you just have to add 'ebhealthcheck.apps.EBHealthCheckConfig' to INSTALLED_APPS

Package github page – https://github.com/sjkingo/django-ebhealthcheck