Situation

Get Parameter Store When EC2 Launch New Instance

How To

Add Parameter Store

Add Role Policy Into IAM Instance Profile

create new policy get-demo-parameter and attach to iam instance profile

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": "ssm:GetParameter",
            "Resource": "arn:aws:ssm:ap-northeast-1:<your-account-id>:parameter/<parameter-store-name>
        }
    ]
}

Launch New VM Instance And Add UserData

User Data Script

#!/bin/bash 

export AWS_DEFAULT_REGION=ap-northeast-1

get_para=$(aws ssm get-parameter --name <parameter-name> --query Parameter.Value --output text) 
echo $get_para > /tmp/para.txt

After Boot Finished

Debug From Cloud-Init Log

cat /var/log/cloud-init.log