Parse user/metadata/runtime data from cloudformation into EC2 - windows

Question

I am trying to setup my windows 2016 instances in cloudformation stack and It requires some inputs from user that is taken in parameter section to be transferred into the instance and the software inside would require those parameters. Till now i only found that i can send it by parsing it inside a powershell script while saving the data into a text file. Is there anyother method? or more efficient method to do this???

Answer 1

See Bootstrapping AWS CloudFormation Windows Stacks.
In short, you typically use AWS::CloudFormation::Init metadata and cfn-init in UserData to bootstrap and initialize your instances.

Answer 2

Here is an AWS CloudFormation template that can take a parameter from the CloudFormation stack and put that information onto the Windows instance:
AWSTemplateFormatVersion: 2010-09-09
Parameters:
Username:
Type: String
Description: Ask for a username, will be placed on the instance
WindowsAmiId:
Type: 'AWS::SSM::Parameter::Value<AWS::EC2::Image::Id>'
Default: /aws/service/ami-windows-latest/Windows_Server-2019-English-Full-Base
KeyName:
Type: String
Description: Keyname for the keypair to use when launching EC2 instances
Resources:
AppInstance:
Type: AWS::EC2::Instance
Properties:
KeyName: !Ref KeyName
ImageId: !Ref WindowsAmiId
InstanceType: t2.large
UserData:
Fn::Base64: !Sub |
<powershell>
Set-Content -Path 'C:\username.txt' -Value '${Username}'
</powershell>
The result is a file in C:\username.txt that contains the Username parameter that was provided when the stack was launched.
Alternatively, you could call describe-stack to retrieve the parameters.