Packer and patching an ISO configuration, to enable ssh?

Question

I am currently trying to make a vagrant box, using packer. The challenge is that the iso image ( Raspbian Jessie Pixels ) I am depending on has ssh disabled, so that it is preventing the script doing some necessary configuration as part of the packer script.

Does anyone know of an approach where I could over-ride settings in an ISO image, so that I could enable ssh?

The json configuration I have at the moment is as follows:

{
    "builders": [{
        "disk_size": 10140,
        "guest_os_type": "Debian",
        "headless": true,
        "http_directory": "http",
        "iso_checksum": "29c24b21e5a46c6290d980681a7bd1fbc4974111e8ff2730ba8c1f2f53a22a59",
        "iso_checksum_type": "sha256",
        "iso_url": "http://downloads.raspberrypi.org/pixel_x86/images/pixel_x86-2016-12-13/2016-12-13-pixel-x86-jessie.iso",
        "shutdown_command": "echo 'halt -p' > shutdown.sh; echo 'vagrant'|sudo -S sh 'shutdown.sh'",
        "ssh_password": "raspberry",
        "ssh_port": 22,
        "ssh_username": "pi",
        "ssh_wait_timeout": "10000s",
        "type": "virtualbox-iso",
        "vboxmanage": [
            [ "modifyvm", "{{.Name}}", "--memory", "512"],
            [ "modifyvm", "{{.Name}}", "--cpus", "2"]
        ],
        "boot_command": [ ]
    }],
    "post-processors": [
        "vagrant"
    ],
    "provisioners": [{
        "type": "shell",
        "execute_command": "echo 'vagrant'|sudo -S sh '{{.Path}}'",
        "scripts": [
            "scripts/base.sh",
            "scripts/vagrant.sh",
            "scripts/virtualbox.sh"
        ]
    }]
}

Answer 1

There are 3 different ways to enable ssh on the raspbian images. Specifically for headless images:

For headless setup, SSH can be enabled by placing a file named 'ssh', without any extension, onto the boot partition of the SD card. When the Pi boots, it looks for the 'ssh' file. If it is found, SSH is enabled, and the file is deleted. The content of the file does not matter: it could contain text, or nothing at all.

Here's the docs on how Raspbian handles ssh now: https://www.raspberrypi.org/documentation/remote-access/ssh/

You might be able to use floppy_files in your Packer settings to place the ssh file in the root directory along with the image. See https://www.packer.io/docs/builders/virtualbox-iso.html#floppy_files

Good luck!