packer.json

{
  "variables": {
    "access_key": "{{ env `access_key` }}",
    "secret_key": "{{ env `secret_key` }}",
    "region": "{{ env `region` }}",
    "instance_type": "{{ env `instance_type`}}",
    "source_ami": "{{ env `source_ami` }}",
    "aws_ssh_username": "{{ env `aws_ssh_username` }}",
    "device_name": "{{ env `device_name` }}",
    "volume_size": "{{ env `volume_size` }}",
    "ami_name": "{{ env `ami_name` }}",
    "platform": "{{ env `platform` }}",
    "port": "{{ env `port` }}",
    "environment": "{{ env `environment` }}",
    "application_location": "{{ env `application_location` }}",
    "extravars": "{{ env `extravars` }}"
  },
  "builders": [
    {
      "type": "amazon-ebs",
      "access_key": "{{ user `access_key` }}",
      "secret_key": "{{ user `secret_key` }}",
      "region": "{{ user `region` }}",
      "instance_type": "{{ user `instance_type` }}",
      "source_ami": "{{ user `source_ami` }}",
      "ami_name": "{{ user `ami_name` }}",
      "ssh_username": "{{ user `aws_ssh_username` }}",
      "ssh_pty": true,
      "force_deregister": true,
      "force_delete_snapshot": true,
      "launch_block_device_mappings": [
        {
          "device_name": "{{ user `device_name` }}",
          "volume_size": "{{ user `volume_size` }}",
          "volume_type": "gp2",
          "delete_on_termination": true
        }
      ]
    }
  ],
  "provisioners": [
    {
      "type": "ansible",
      "playbook_file": "site.yml",
      "extra_arguments": [
        "--extra-vars", "application_location={{ user `application_location` }} environment={{ user `environment` }} port={{ user `port` }}"
      ]
    }
  ]
}