Amazon EC2 custom AMI not running bootstrap (user-data)

Question

I have encountered an issue when creating custom AMIs (images) on EC2 instances. If I start up a Windows default 2012 server instance with a custom bootstrap/user-data scrip

Answer 1

Another solution that worked for me is to run Sysprep with EC2Launch.

The issue is that AWS doesn't reestablish the route to the profile service (169.254.169.254) in your custom AMI. See response by SanjitPatel in this post. So when I tried to use my custom AMI to create spot requests, my new instances were failing to find user data.

Shutting down with Sysprep, essentially forces AWS re-do all setup work on the instance, as if it were run for the first time. So when you create your instance, shut it down with Sysprep and then create your custom AMI, AWS will setup the profile service route correctly for the new instances and execute your user data. This also avoids manually changing Windows Tasks and executing user data on subsequent boots, as persist tag does.

Here is a quick step-by-step:

1. Create an instance using one of the AWS Windows AMIs (Windows Server 2016 Nano Server doesn't support Sysprep) and passing your desired user data (this may be optional, but good to make sure AWS wires setup scripts correctly to handle user data).
2. Customize your instance as needed.
3. Shut down your instance with Sysprep. Just open EC2LaunchSettings application and click "Shutdown with Sysprep". Full instructions here.
4. Create your custom AMI from the instance you just shut down.
5. Use your custom AMI to create other instances, passing user data on instance creation. User data will be executed on instance launch. In my case, I used Spot Request screen, which had a User Data text box.

Hope this helps!