main.json

{
    "builders": [
        {
            "accelerator": "kvm",
            "boot_command": [
                "<tab> console=ttyS0 text ks=http://{{ .HTTPIP }}:{{ .HTTPPort }}/centos-8.ks<enter><wait>"
            ],
            "boot_wait": "10s",
            "disk_interface": "virtio",
            "disk_size": 3072,
            "format": "{{ user `format` }}",
            "headless": true,
            "http_directory": "http",
            "iso_checksum": "a7993a0d4b7fef2433e0d4f53530b63c715d3aadbe91f152ee5c3621139a2cbc",
            "iso_checksum_type": "sha256",
            "iso_url": "http://mirror.cs.vt.edu/pub/CentOS/8/isos/x86_64/CentOS-8-x86_64-1905-boot.iso",
            "net_device": "virtio-net",
            "output_directory": "build",
            "qemuargs": [
                [
                    "-monitor",
                    "unix:qemu-monitor.sock,server,nowait"
                ],
                [
                    "-serial",
                    "pipe:/tmp/qemu-serial"
                ],
                [
                    "-m",
                    "896M"
                ]
            ],
            "shutdown_command": "systemctl poweroff",
            "ssh_password": "passwd",
            "ssh_timeout": "10m",
            "ssh_username": "root",
            "type": "qemu",
            "vm_name": "centos-8-amd64-{{ timestamp }}.{{ user `format` }}"
        }
    ],
    "post-processors": [
        [
            {
                "s3_bucket_name": "{{ user `bucket_name` }}",
                "tags": {
                    "Description": "packer amazon-import"
                },
                "type": "amazon-import"
            }
        ]
    ],
    "variables": {
        "format": "qcow2",
        "bucket_name": "vm-import-bucket"
    }
}