template.json

{
    "min_packer_version": "0.8.6",
    "description": "Bare CentOS 7 prepped for AMI import",
    "variables": {
        "profile": "xfs",
        "disk_size": "8192",
        "memory": "6122",
        "cpus": "4",
        "ssh_username": "centos",
        "ssh_password": "centos"
    },
    "builders": [
        {
            "type": "virtualbox-iso",
            "vm_name": "centos7-ec2-{{user `profile`}}",
            "headless": true,
            "guest_os_type": "RedHat_64",
            "disk_size": "{{user `disk_size`}}",
            "vboxmanage": [
                ["modifyvm", "{{.Name}}", "--memory", "{{user `memory`}}"],
                ["modifyvm", "{{.Name}}", "--cpus", "{{user `cpus`}}"]
            ],
            "iso_url": "http://mirror.steadfast.net/centos/7/isos/x86_64/CentOS-7-x86_64-NetInstall-1511.iso",
            "iso_checksum": "9ed9ffb5d89ab8cca834afce354daa70a21dcb410f58287d6316259ff89758f5",
            "iso_checksum_type": "sha256",
            "http_directory": "http",
            "boot_command": ["<tab> text ks=http://{{.HTTPIP}}:{{.HTTPPort}}/ks-{{user `profile`}}.cfg<enter><wait>"],
            "boot_wait": "10s",
            "ssh_username": "{{user `ssh_username`}}",
            "ssh_password": "{{user `ssh_password`}}",
            "ssh_port": 22,
            "ssh_wait_timeout": "10000s",
            "guest_additions_mode": "disable",
            "shutdown_command": "sudo -S shutdown -P now",
            "output_directory": "output-{{user `profile`}}",
            "format": "ova"
        }
    ],
    "provisioners": [
        {
            "type": "file",
            "source": "10-growpart.cfg",
            "destination": "/tmp/10-growpart.cfg"
        },
        {
            "type": "shell",
            "execute_command": "sudo -S sh '{{.Path}}'",
            "inline": [
                "yum -y install cloud-init cloud-utils cloud-utils-growpart",
                "mv /tmp/10-growpart.cfg /etc/cloud/cloud.cfg.d/10-growpart.cfg",
                "chown root:root /etc/cloud/cloud.cfg.d/10-growpart.cfg",
                "systemctl enable cloud-config.service",
                "systemctl enable cloud-final.service",
                "systemctl enable cloud-init-local.service",
                "systemctl enable cloud-init.service",
                "echo \"{{user `ssh_username`}}:$(openssl rand -base64 32)\" | chpasswd",
                "shred -u /etc/ssh/*_key /etc/ssh/*_key.pub",
                "shred -u /root/.*history  /home/centos/.*history",
                "dd if=/dev/zero of=/zeros bs=1M",
                "rm -f /zeros"
            ]
        }
    ]
}