diskless-workstation/docs/TODO.md

TODO — diskless fleet boot system

Persistent backlog, kept in sync with the working session task tracker. Status: [ ] pending · [~] in progress · [x] done.

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[ ] 1. Port the dracut module off network-legacy → network-manager

Durable replacement for the current dhcp-client stopgap. dhclient is deprecated in RHEL 9 and will eventually leave the repos; the build only works today because the provisioner installs dhcp-client so network-legacy passes dracut's check().

• Rewrite both network bring-up paths in ../files/dracut/95dot1x-macsec/dot1x-macsec-up.sh: the secure path's ifup macsec0 and the rd.dot1x=0 bypass path's ifup $NIC — use nmcli/NetworkManager-in-initramfs (or ip= cmdline + the nm module) instead.
• Change depends() network-legacy → network-manager in ../files/dracut/95dot1x-macsec/module-setup.sh.
• Update add_dracutmodules in ../files/etc/dracut.conf.d/90-diskless.conf.
• Drop dhcp-client from the provisioner dnf install in ../diskless.pkr.hcl.
• Re-verify the lsinitrd assertion.
• Gate: full boot-chain smoke test (swtpm + hostapd + FreeRADIUS) before merge, per CLAUDE.md.

[ ] 2. Apply RHEL9 STIG hardening to the built image

OpenSCAP + SCAP Security Guide (xccdf_org.ssgproject.content_profile_stig), run as a Packer provisioner after dnf install and before the dracut/initramfs build and cleanup.

• Tailoring (autotailor): unselect rules this architecture can't satisfy — separate-partition rules (single erofs root + tmpfs overlay; satisfy intent with nodev,nosuid,noexec tmpfs mounts), GRUB/kernel-cmdline rules (no GRUB), and AIDE/file-integrity rules (dm-verity is the documented compensating control).
• Kernel params → UKI cmdline in ../scripts/extract-artifacts.sh before signing: audit=1 audit_backlog_limit=8192 slub_debug=P page_poison=1 vsyscall=none (+ fips=1 if FIPS).
• Reproducibility guard: strip non-deterministic remediation output (SSH host keys → regen at boot into overlay, AIDE db, timestamps, fresh UUIDs) so the verity hash stays stable.
• Audit logging: audisp-remote/rsyslog to a central collector addressed by DNS name (host-generic).
• Optional FIPS: fips=1 cmdline + 01fips dracut module + FIPS crypto policy.
• CI: run oscap eval (no --remediate) to publish an ARF+HTML STIG report as a build artifact; optionally hard-fail below a score threshold.
• Decisions needed before implementing: FIPS on/off · remote-audit collector DNS name (or ephemeral/none for lab) · CI fail-on-score threshold vs report-only.
• Note: orthogonal to the rd.dot1x=0 test toggle, but a full STIG production posture wants 802.1X re-enabled.

[ ] 3. Roll the errata into design doc v3

Once the boot path is validated and item 1 lands, fold design-v2-errata.md into the source design document and re-export a v3 PDF (key change: rootovl → systemd.volatile=overlay in §3 step 8 and §5). Retire/reset the errata afterward. Needs the design-doc source (not in this repo).

[ ] 4. Kiosk mode — autologin + fullscreen Chromium loading a URL

Make the diskless workstation boot straight into a locked-down kiosk: a fullscreen Chromium showing a configured site (initial target: Reddit). All baked at build time into the root tree (immutable erofs/verity root; runtime is the tmpfs overlay), fleet-generic (no per-host state).

• Graphical stack (keep it minimal): add a Packer provisioner installing a lightweight kiosk compositor + browser. Preferred: cage (Wayland single-app kiosk compositor) + Mesa (software GL fallback for VMs/no-GPU); X11 + a minimal WM (matchbox/openbox) as the alternative. Chromium on Rocky 9 is in EPEL — enabling EPEL adds a repo/supply-chain surface (decision below).
• Autologin + session: dedicated unprivileged kiosk user; launch the session via a kiosk.service running cage -s -- chromium --kiosk … (or greetd + cage). Stage units/configs under files/ like the other provisioned config.
• Chromium flags: --kiosk --noerrdialogs --disable-infobars --incognito --no-first-run --disable-session-crashed-bubble <URL>. Writable profile/cache land on the systemd.volatile=overlay tmpfs (RAM-backed, ephemeral) — fine, but watch RAM sizing; pin --user-data-dir/--disk-cache-dir to a tmpfs path if needed.
• Kiosk URL = Packer var (e.g. kiosk_url, default the target site), baked into the launch command; keep it host-generic (per-env via DNS if ever needed).
• Verify in boot test: graphical session comes up on real/VM display, Chromium fullscreen loads the URL over the booted network (works with the current rd.dot1x=0 test path / open network).
• Decisions: Wayland(cage) vs X11; accept EPEL for Chromium (vs another source); confirm the target URL.
• ⚠ Conflict with item 2 (STIG): passwordless autologin and a desktop browser are STIG findings and enlarge the attack surface/image. Reconcile — e.g. a tightly-constrained kiosk session + documented deviation — when hardening lands.

[~] 5. Deploy & validate the end-to-end boot path (open-network test)

In progress. Stand up serving/ (dnsmasq + nginx + SPDK) per serving/README.md, rebuild the UKI with nvmet_traddr=nvme.fleet.lab (now a Packer var — older UKIs have the literal NVMET_TRADDR placeholder and won't connect), then boot a UEFI HTTP-boot client (Secure Boot OFF, unsigned UKI; no TPM needed in rd.dot1x=0 mode) on the boot LAN.

• Pass criteria: UKI fetched over HTTP → initramfs → DHCP on NIC → NVMe/TCP namespace connected → dm-verity root mapped → systemd.volatile=overlay writable → multi-user.
• This validation gates item #1 (network-manager port) and item #3 (errata → design v3).

[ ] 6. Rolling fleet updates (multi-version serve → cohort reboots)

Image-based, reboot-to-update across many live workstations. Hosts are immutable (read-only erofs/verity root over NVMe/TCP, ephemeral overlay), so updates are atomic A/B reboots, never in-place. The released OCI artifact + digest-pinned manifest + roothash coupling already give the atomic unit and instant rollback; this item builds the rollout machinery around it.

• Serve versions side-by-side (must not overwrite a live rootfs): extend serving/ so SPDK/nvmet exposes each release as its own subsystem/NQN (nqn…:rootfs-<ver>) and nginx serves multiple fleet-<ver>.efi (keep current + previous). Make the UKI's NQN version-specific so each signed UKI connects only its matching namespace (constant discovery DNS name).
• Version selection at boot: dnsmasq cohort tagging (MAC / vendor class / assigned tag) hands each cohort a different option-67 UKI URL. Moving a cohort's URL = assigning the release.
• Control plane + in-image reboot agent: a baked-in systemd timer polls a "desired version" endpoint and reboots when idle / in a maintenance window (or out-of-band via Redfish/BMC). Stagger + jitter reboots to avoid UKI-fetch / NVMe-connect storms.
• Staged rollout: canary → waves (10/50/100%) with health gates (multi-user reached, NVMe connected, dm-verity mapped, kiosk URL rendered, prod: MACsec/802.1X up); auto-halt on threshold.
• Rollback: repoint cohort URL to previous UKI + reboot (current+previous stay served); security rollback via dbx-revoke / TPM monotonic counter (design §6).
• Drain & retire an old version only when SPDK/nvmet reports zero connected controllers on it.
• Availability: run NVMe/TCP target replicas behind distinct discovery entries (design §7) — never serve the whole fleet from one unreplicated node, especially mid-rollout (N versions + reboot bursts).
• Note: kiosk content changes are server-side (the website) and need no fleet update — only OS/UKI/rootfs changes require a reboot.

[ ] 7. Harden / evaluate the NVMe-oF target (serving-node resilience)

There is no production-grade memory-safe NVMe-oF target — the Rust NVMe work is all driver/initiator-side (vroom, RedLeaf, Rust-for-Linux); the only production targets are C (Linux kernel nvmet, SPDK). So this is serving-node hardening, not a language swap. dm-verity already removes the target from the clients' integrity TCB (verify-on-read rejects tampered blocks), so the risk is RCE/DoS on the node that holds the fleet's disk, not client integrity. The export is read-only + single-namespace = inherently small attack surface.

• Evaluate kernel nvmet vs SPDK for the target: kernel nvmet keeps the data path in the hardened/fuzzed kernel with a tiny userspace footprint (arguably a better attack-surface story); SPDK is a userspace C daemon (current choice, needs hugepages + caps). Decide per environment.
• Confine the target (whichever): unprivileged, drop caps, seccomp + SELinux/AppArmor profile, read-only container, minimal mounts; minimal immutable serving image, digest-pinned.
• Network-isolate :4420 so only the boot VLAN reaches the target (compose with 802.1X/MACsec segmentation in prod).
• Replicas behind distinct discovery entries (availability is the real risk — it's the fleet's disk). Ties into #6 (rolling updates) availability.
• Revisit a memory-safe target only if/when an off-the-shelf one matures (e.g. a future Rust-for-Linux nvmet).