os-build/docs/building.md

Building Arcline OS

Prerequisites

A Debian-family host (or container) with root/sudo:

debootstrap        # rootfs bootstrap
squashfs-tools     # ISO rootfs compression
grub2-common       # grub-mkrescue (hybrid ISO)
xorriso cpio       # ISO assembly
bash make curl git # build orchestration
go (≥ 1.21)        # only needed for `make toolchain`

Check or install them:

scripts/check-host-deps.sh            # report what's missing
scripts/check-host-deps.sh --install  # apt-get install the missing bits

Quickstart

make check          # validate the tree (fast, offline, safe)
make rootfs-server  # build just the server rootfs
make iso-server     # build a bootable server ISO
make iso            # build all three editions
make image-cloud    # build the cloud edition as a qcow2 disk image
make toolchain      # build the 11 Go tools into .deb
make vendor         # build Grafana/Loki/Promtail .debs
make test           # run smoke tests against built rootfs(es)

Outputs

Everything lands under build/:

Path	Contents
build/rootfs/<edition>/	extracted rootfs (from make rootfs-*)
build/artifacts/arcline-<edition>-<version>-<arch>.tar.xz	archived rootfs
build/artifacts/arcline-<edition>-<version>-<arch>.iso	bootable live ISO
build/artifacts/arcline-<edition>-<version>-<arch>.qcow2	bootable disk image
build/debs/*.deb	Arcline toolchain + vendor packages

Each artifact ships with a .sha256 checksum file.

Disk images & installing

• make image-<edition> builds a bootable qcow2 disk image (the cloud edition's primary output; also handy for VM-testing server/workstation). Options: --format raw, --size 4G, --boot efi.
• scripts/install.sh /dev/sdX --edition server installs a built rootfs onto a real disk (asks for explicit confirmation, then partitions, lays out btrfs subvolumes, installs GRUB, and writes a real fstab). Both reuse the shared scripts/deploy-disk.sh.

Secure boot

Optional, MOK-based. See secureboot:

scripts/secureboot/gen-keys.sh
ARCLINE_SIGN=1 make iso-server

Reproducibility knobs

Set these as environment variables or edit versions.mk:

Variable	Meaning	Default
VERSION	release version string	0.1.0
DEBIAN_SUITE	Debian base	trixie
ARCH	target architecture	amd64
DEBIAN_MIRROR	mirror for the base	http://deb.debian.org/debian
ARCLINE_LIVE	install live-boot into rootfs	unset (set by ISO build)
ARCLINE_LOCK_ROOT	lock root account (passwd -l root)	0
ARCLINE_EXTRA_REPOS	fetch grafana/loki upstream repos	0
ARCLINE_TOOLCHAIN	toolchain in image builds	auto
ARCLINE_SIGN	sign boot chain with the MOK (secure boot)	0
BOOT	bootloader in the image: bios → grub-pc, efi → grub-efi-amd64 + shim-signed	bios

Why one bootloader? grub-pc and grub-efi-amd64 conflict, so apt fails with "held broken packages" if both are in a package list. Arcline ships exactly the one matching BOOT (injected by build-rootfs.sh). For a UEFI + secure-boot build: BOOT=efi make iso-server (or make image-cloud with BOOT=efi). The deployed image/install uses the same variable by default.

Building without the Arcline toolchain

The 11 Go tools (see docs/toolchain.md) are optional in an image — a normal make iso-server with no .debs in build/debs/ already produces a minimal, toolchain-free image. This is controlled by ARCLINE_TOOLCHAIN:

Mode	Behaviour
auto (default)	install the tools if build/debs/*.deb exist, otherwise build without them (with a warning)
skip	never install the tools, even if debs are present
require	fail the build if no toolchain debs are available

Examples:

make iso-server                # auto: tools in if you ran `make toolchain`
make iso-server-minimal        # skip: guaranteed toolchain-free image
ARCLINE_TOOLCHAIN=skip make iso-server
ARCLINE_TOOLCHAIN=require make iso-server   # release builds must ship the tools

Everything else — hardened base, firewall, btrfs, observability (Prometheus/node_exporter are Debian-main packages), zero-telemetry — is independent of the toolchain and always included.

Notes on the ISO

The ISO boots a live system (via live-boot): the rootfs is compressed to a squashfs and mounted on boot, so you can try an edition before installing it to disk. The same rootfs can be installed with the btrfs layout via btrfs/init.sh (the installer is follow-up work — see docs/architecture.md).

Burning the ISO

The ISO is hybrid (BIOS + UEFI). Write it to a USB stick with dd (or Ventoy), not as a file copy:

sudo dd if=build/artifacts/arcline-server-0.1.0-amd64.iso of=/dev/sdX bs=4M status=progress

The build verifies the finished ISO actually contains both boot entries and prints ✓ EFI boot entry present / ✓ BIOS boot entry present; BOOT=efi builds fail if the EFI entry is missing.

UEFI says "make sure there is a bootable uefi x64 image"

That firmware error means the ISO had no UEFI boot entry. grub-mkrescue builds the ISO bootloader from the build host's GRUB, so the host needs the UEFI modules even though the image is BOOT=efi:

sudo apt-get install -y grub-efi-amd64-bin grub-pc-bin mtools
scripts/check-host-deps.sh   # should now pass; rebuild the ISO

If the entry was present but it still won't boot, enable/disable Secure Boot (our BOOT=bios ISOs are unsigned and will be refused by Secure Boot — use BOOT=efi make iso-server plus the MOK flow in docs/secureboot.md for signed, Secure-Boot-friendly media).