AWS instance Operating System Version

Hello,

I will give you some details about how to get the OS level information in different ways so that you can take your decision accordingly if that can be used for your use case.

https://aws.amazon.com/premiumsupport/knowledge-center/ec2-linux-find-os-platform-or-version/

Referring the above doc mention three ways to check the OS versions,

1. View the Platform details or AMI ID information.
2. View the instance's console logs or screenshot.

However for both of these methods you need to manually check the information using the AWS console for each of your instance, additionally note that as already mentioned AWS has limited visibility into the software or OS that's running on an instance. This means that AWS can't provide specific OS-related information. AWS predicts the information in the Platform details field based on the AMI name and description. Because of this, the listed platform isn't always accurate for the preceding two methods. If the console logs are enabled by default, then the logs usually show the OS and version that your instance uses.

Now coming to the third method mentioned which is bit more informative,

3. View platform information for AWS Systems Manager Managed instances.

Here you can use ssm describe-instances-information command to get the platform based information however this can only be used for managed instances and even in this case you will not get the exact OS version you will get a general OS type name for example - Ubuntu, SLES, Amazon Linux AMI, However making all instances managed in your account just to know these details might not be feasible for you.

[+] https://docs.aws.amazon.com/cli/latest/reference/ssm/describe-instance-information.html