How to get free-tier AMI in AWS using python with boto3

Question

I'm trying to build a function in python that creates a new ec2 instance in a specific region. For the function to work I need to specify the AMI of this new instance. The problem is that the same AMI (for example Amazon Linux) has a different id in different regions and I can't use an image of one region in another region instance.

and I can't understand how do I get this AMI id in this specific region

def create_instance(region):
        ec2 = boto3.resource('ec2', region)
        instances = ec2.create_instances(InstanceType='t2.micro',
                                         MinCount=1, MaxCount=1,
                                         ImageId='AMI-id') # What do I put here?

For now, it's not really important what the AMI is besides the fact that it is Linux and free-tier, So maybe searching a specific known free-tier Linux AMI will work.

I know you can get all AMI using describe_images() function but how do I filter only those that are Linux (Could be a specific version) and free-tier

boto3.client('ec2').describe_images(Filters["""What do I write here to get only linux free-tier AMI"""])

Answer 1

AWS System Manager maintains the curated list of AWS Linux 2 AMIs at /aws/service/ami-amazon-linux-latest/amzn2-ami-hvm-x86_64-gp2

Here is the CLI call:

$ aws ssm get-parameters --names /aws/service/ami-amazon-linux-latest/amzn2-ami-hvm-x86_64-gp2 --region us-east-1

{
    "Parameters": [
        {
            "Name": "/aws/service/ami-amazon-linux-latest/amzn2-ami-hvm-x86_64-gp2",
            "Type": "String",
            "Value": "ami-0323c3dd2da7fb37d",
            "Version": 27,
            "LastModifiedDate": 1586395100.713,
            "ARN": "arn:aws:ssm:us-east-1::parameter/aws/service/ami-amazon-linux-latest/amzn2-ami-hvm-x86_64-gp2"
        }
    ],
    "InvalidParameters": []
}

You should be able to do the same in Python with SSM BOTO3 API.