ISO Image Generation

Build a bootable NixOS ISO using the Hephaestus environment.

TIP

For the full workflow (build ISO → install on hardware → bootstrap Kubernetes → deploy Flux), see the OpenStack Cluster Bootstrap.

Build

git clone git@github.com:RPCU/hephaestus.git && cd hephaestus
devenv shell
build-iso --argstr partition root --argstr cloud false

Output goes to ./output/.

Parameters

Parameter	Description
--argstr partition	Disk layout: root (NVMe/UEFI), root-grub (BIOS), small (VMs), test
--argstr cloud	false (baremetal), true (cloud-init), or a hostname string
--argstr disk	Optional: specific device (e.g., /dev/nvme0n1)

Partition Layouts

Defined in installer/partitions/:

Profile	Boot	Layout
root	UEFI	/var 200G, /nix 200G, / 100G (LVM on NVMe)
root-grub	BIOS	Single root LV
small	UEFI	/var 5G, /nix 30G, / 2G

First Boot Behavior

1. ISO auto-logs in as nixos and runs sudo installer
2. Installer: auto-detects disk → wipes → partitions (disko) → nixos-install → reboot
3. First boot: ginx pulls hephaestus repo → colmena apply-local --sudo → reboot into final state

After this, the node auto-updates via ginx every 60 seconds — see Deployment & Upgrades.

Testing in QEMU

devenv exec runIso --argstr partition root --argstr cloud false

Boots the ISO in a 50G virtual disk, SSH at localhost:2222.