private IP addresses of MWAA Web server keeps changing

The private IP address of the MWAA web server changes because it's running on an AWS Elastic Network Interface (ENI). ENIs are automatically created when you launch a new Amazon MWAA environment. When an environment is updated or experiences an internal failure, the ENI may be replaced, resulting in a new private IP address.

To avoid issues with changing IPs, instead of using an IP address in your Route 53 record, you should create a CNAME record pointing to the MWAA environment's web server hostname. This way, the URL will continue to work even if the IP address changes.

Here's an example of how to create a CNAME record in Route 53:

1. Open the Route 53 Management Console in AWS.
2. Select the hosted zone where you want to create the CNAME record.
3. Click "Create record."
4. Choose "Simple routing" and click "Next."
5. Click "Define simple record."
6. In the "Record name" field, enter the desired subdomain for your MWAA environment (e.g., mwaa.example.com).
7. For "Value/Route traffic to," choose "Alias to another record in this hosted zone" and enter the web server hostname of your MWAA environment (e.g., abc123xyz.mwaa.environment.amazonaws.com).
8. Set the "Record type" to "CNAME."
9. Choose an appropriate TTL (Time to Live) value, such as 300 seconds or 5 minutes.
10. Click "Create records."

Now, your custom domain (e.g., mwaa.example.com) should resolve to the MWAA environment's web server hostname, regardless of the underlying private IP address changes.