packer-template.json

{
  "variables": {
    "swap_size":         "",
    "disk_size":         "40000",
    "memmory_size":      "1024",
    "cpus":              "1",
    "vm_name":           "@VM_NAME@",
    "iso_url":           "@ISO_URL@",
    "iso_checksum_type": "sha256",
    "iso_checksum":      "@ISO_CHECKSUM@",
    "nixos_channel":     "@NIXOS_CHANNEL@"
  },
  "builders": [
    {
      "type": "virtualbox-iso",
      "vm_name": "{{ user `vm_name` }}",
      "guest_os_type": "@GUEST_OS_TYPE@",
      "disk_size": "{{ user `disk_size` }}",
      "boot_wait": "0.7m",
      "boot_command": [
        "root<enter>",
        "export HTTP_IP={{ .HTTPIP }}<enter>",
        "export HTTP_PORT={{ .HTTPPort }}<enter>",
        "export SWAP=\"{{ user `swap_size` }}\"<enter>",
        "export NIXOS_CHANNEL=\"{{ user `nixos_channel` }}\"<enter>",
        "curl http://{{ .HTTPIP }}:{{ .HTTPPort }}/boot.sh -s > boot.sh<enter><wait>",
        "sh boot.sh<enter><wait>"
      ],
      "http_directory": "nixos",
      "iso_url": "{{ user `iso_url` }}",
      "iso_checksum_type": "{{ user `iso_checksum_type` }}",
      "iso_checksum": "{{ user `iso_checksum` }}",
      "shutdown_command": "sudo shutdown -h now",
      "ssh_username": "vagrant",
      "ssh_key_path": "keys/vagrant.key",
      "ssh_wait_timeout": "25m",
      "virtualbox_version_file": ".vbox_version",
      "guest_additions_mode": "disable",
      "vboxmanage": [
        ["modifyvm", "{{.Name}}", "--memory", "{{ user `memmory_size` }}"],
        ["modifyvm", "{{.Name}}", "--cpus", "{{ user `cpus` }}"]
      ]
    }
  ],
  "provisioners": [
    {
      "type": "shell",
      "execute_command": "sudo -E sh '{{.Path}}'",
      "script": "scripts/postinstall.sh"
    }
  ],
  "post-processors": [
    {
      "type": "vagrant",
      "output": "@VM_NAME@-{{.Provider}}.box"
    }
  ]
}