spot_instances_aws.json

{
 "variables": {
        "aws_access_key": "{{env `AWS_ACCESS_KEY_ID`}}",
        "aws_secret_key": "{{env `AWS_SECRET_ACCESS_KEY`}}"
    },
    "builders": [
        {
            "access_key": "{{user `aws_access_key`}}",
            "ami_name": "packer-example-spot-instance",
            "force_deregister": true,
            "instance_type": "m3.medium",
            "region": "us-east-1",
            "secret_key": "{{user `aws_secret_key`}}",
            "source_ami_filter": {
                "filters": {
                    "virtualization-type": "hvm",
                    "name": "ubuntu/images/*ubuntu-xenial-16.04-amd64-server-*",
                    "root-device-type": "ebs"
                },
                "owners": ["099720109477"],
                "most_recent": true
            },
            "ssh_username": "ubuntu",
            "type": "amazon-ebs",
            "spot_price": "auto",
            "spot_price_auto_product": "Linux/UNIX",
            "run_volume_tags": {
                "Name": "Example of Spot Instances",
                "Project": "Packer-Examples"
            }            
        }
    ]
}