ISO-based

ISO-based unattended installation is ideal for automating Airlock Gateway deployments in on-premises environments. It allows for consistent, repeatable installations without manual intervention, making it suitable for large-scale deployments or environments requiring rapid provisioning.

Airlock Gateway supports two alternative methods of ISO-based unattended installation:

Method	Typical use case	How kernel parameters are applied
Automated kernel-line injection	Building a virtual machine template with an automation tool (e.g., Packer)	A helper injects the parameters at the boot loader prompt (no ISO editing).
Modified ISO image	Installing bare-metal or virtual machines without interaction	The ISO image itself is unpacked, the boot loader configuration file is edited, and the image is repacked.

Alternative A: automated kernel-line injection (Packer example)

To enable unattended installation, automation tools such as HashiCorp Packer can inject kernel parameters into the boot process of the virtual machine. Specifically the VMware ISO builder in Packer, can be used with VMware products. The boot_wait and boot_command builder options can be used to enter kernel parameters via the boot loader at the start of the boot process:

Example

{
   "type": "vmware-iso",
   ...
   "iso_url": "./airlock_ISO_x64_8.5.iso",
    "iso_checksum": "none", 
   "boot_wait": "5s",
   "boot_command" : [
       "<home>", "<tab>",
       "alinst.interactive=0 alinst.rootpw=xxxx alinst.dhcp=1" , "<enter>"
   ],
   "ssh_username": "root",
   "ssh_password": "xxxxxx",
   "ssh_timeout": "60m",
   ...
}

The ellipses (...) indicate that this example is incomplete.
alinst.interactive=0 switches the installer to fully automated mode.
Any other kernel parameter (i.e., static ip=, proxy settings, debug flags) can be appended the same way.

Alternative B: modified ISO image (Linux open-source tools example)

Prerequisites

Linux workstation
xorriso – to extract and re-author the ISO filesystem
isohybrid – to make the rebuilt ISO image bootable from USB and optical media

Creating a modified ISO image

Unpack the original ISO image.

ISO=./airlock_ISO_x64_8.5.iso
DEST=./isotmp

xorriso -no_rc -osirrox on:auto_chmod_on \
        -indev "$ISO" -extract "/" "$DEST"

For both BIOS and EFI boot modes, adapt the respective boot loader configuration file as follows:
- Extend the kernel command line defined in these files with the required kernel parameters.
- Add at least alinst.interactive=0 to disable interactive prompts and alinst.sshkey= (preferred) or alinst.rootpw= as authentication option.
Notice
We recommend to update both boot loader configuration files consistently to ensure the resulting ISO image remains universally bootable.
Example of a modified EFI boot loader configuration file ($DEST/EFI/BOOT/grub.cfg):

Example

menuentry 'Install Airlock Gateway' {
    linuxefi /images/pxeboot/vmlinuz \
      inst.stage2=hd:LABEL=Airlock \
      inst.ks=hd:LABEL=Airlock:/airlock/kickstart/airlock_install.cfg \
      alinst.interactive=0 alinst.sshkey="ssh-ed25519 AAAA..."
    initrdefi /images/pxeboot/initrd.img
}

Example of a modified BIOS boot loader configuration file ($DEST/isolinux/isolinux.cfg):

Example

label Airlock
  menu label Install Airlock Gateway
  menu default   # make this entry the default
  kernel vmlinuz
  append initrd=initrd.img \
         inst.stage2=hd:LABEL=Airlock \
         inst.ks=hd:LABEL=Airlock:/airlock/kickstart/airlock_install.cfg \
         alinst.interactive=0 alinst.sshkey="ssh-ed25519 AAAA..."

Notice
This entry must be set as the default boot option. Ensure that the line menu default is present in this entry and removed from all other boot entries.
Repack the ISO image.

Example

source "${DEST}/airlock/create-iso.inc"
eval $(create_airlock_iso_cmd "${DEST}" ./airlock_auto.iso)

The resulting airlock_auto.iso file boots on BIOS and UEFI systems and starts the installation without user interaction.

Once the Gateway boots for the first time, continue with System provisioning to create an admin account and issue a JWT for REST-based automation.