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Check NixOS configurations / eval-hosts (pull_request) Successful in 10m42s
The iPXE menu's "nixos" entry actually chain-loads this flake's own custom auto-installer image, not a stock NixOS image — rename it to "auto-installer" (label "NixOS Auto-Installer") so the menu says what it boots, and set networking.hostName on netbootSystem to match, so the generated system name (nixos-system-auto-installer-*) and staged directory (/srv/pxe/http/auto-installer) agree with the menu entry too. Add a second, genuinely vanilla NixOS minimal netboot image (netbootMinimalSystem in flake.nix — nixpkgs' netboot-minimal.nix on its own, none of modules/installer/common.nix's auto-installer wiring), built from source the same way as the auto-installer image and exposed as packages.x86_64-linux.pxe-minimal. Staged and menu-wired the same way, as "nixos-minimal" (item, hostname, and directory all matching). modules/pxe-boot/stage-installer-artifacts.nix is generalized to stage both images via a shared rule-builder instead of one hardcoded set of paths. Verified: nix eval confirms both images' config.system.name matches their menu entry/directory names, the pxe-boot host itself builds clean with the new menu.ipxe, and the new pxe-minimal image was booted directly under QEMU (kernel+initrd, no KVM) to a working login shell with hostname nixos-minimal, no hang.
125 lines
4.2 KiB
Markdown
125 lines
4.2 KiB
Markdown
# pxe-boot
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The `pxe-boot` host serves HTTP boot assets for iPXE clients — including
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self-staged copies of both this flake's own auto-installer netboot image
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(see `docs/auto-installer.md` for what that image actually is and does once
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booted) and a vanilla, unmodified NixOS minimal netboot image for plain
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rescue/inspection use.
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## Host Role
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- Hostname: `pxe-boot`
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- Web service: nginx on TCP port 80
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- PXE root: `/srv/pxe`
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- HTTP root for scripts and images: `/srv/pxe/http`
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- TFTP root for first-stage bootloaders: `/srv/pxe/tftp`
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- iPXE entry script: `/srv/pxe/http/boot.ipxe`
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- Generated iPXE menu: `/srv/pxe/http/menu.ipxe`
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- SystemRescue iPXE script: `/srv/pxe/http/systemrescue.ipxe`
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- TFTP fallback script: `/srv/pxe/tftp/autoexec.ipxe`
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- Boot binaries copied from the Nix `ipxe` package:
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- `/srv/pxe/tftp/ipxe.efi`
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- `/srv/pxe/tftp/undionly.kpxe`
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## Directory Layout
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The host creates these directories with systemd tmpfiles:
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```text
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/srv/pxe
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/srv/pxe/http
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/srv/pxe/http/images
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/srv/pxe/http/auto-installer
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/srv/pxe/http/nixos-minimal
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/srv/pxe/http/systemrescue
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/srv/pxe/http/ubuntu
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/srv/pxe/http/rescue
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/srv/pxe/tftp
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```
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Mount shared image storage under `/srv/pxe/http`, preferably
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`/srv/pxe/http/images` unless a menu entry expects files in a specific
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directory such as `/srv/pxe/http/auto-installer`.
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The HTTP iPXE chain is:
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```text
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undionly.kpxe or ipxe.efi
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-> autoexec.ipxe from the TFTP root, when iPXE requests it
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-> http://192.168.2.247/boot.ipxe
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-> http://192.168.2.247/menu.ipxe
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```
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The generated menu currently exposes entries for:
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- NixOS Auto-Installer
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- NixOS Minimal
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- SystemRescue environment
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- iPXE shell
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- Reboot
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Both NixOS entries chain-load a `netboot.ipxe` staged into their own
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directory (`/srv/pxe/http/auto-installer/netboot.ipxe` and
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`/srv/pxe/http/nixos-minimal/netboot.ipxe`), each nixpkgs' own generated
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netboot iPXE script (correct `init=`/`initrd=` kernel parameters included)
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rather than a hand-rolled boot line — that script in turn expects its
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kernel/initrd siblings in the same directory. Each directory's three files
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(`bzImage`, `initrd`, `netboot.ipxe`) are built from source and staged
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automatically by `modules/pxe-boot/stage-installer-artifacts.nix` via
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`systemd.tmpfiles.rules` — no manual operator step required:
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- `auto-installer` is this flake's own `netbootSystem` (`flake.nix`) — the
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same auto-installer image `nix build .#pxe` produces. See
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`docs/auto-installer.md`.
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- `nixos-minimal` is `netbootMinimalSystem` (`flake.nix`) — nixpkgs'
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`netboot-minimal.nix` composed on its own, with none of this flake's
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auto-installer wiring (no `common.nix`, no `auto-install.sh`, no baked
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host keys or custom users). Same `nix build .#pxe-minimal` mechanism as
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the auto-installer image, just a different module composition. Useful
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as a plain rescue/inspection shell that doesn't assume anything about
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this flake.
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Both images set `networking.hostName` to match their menu entry/staged
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directory name (`auto-installer` / `nixos-minimal`), so each one's
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generated system name (`nixos-system-<name>-*`) is self-describing rather
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than the nixpkgs default of `nixos-system-nixos-*` for both.
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The SystemRescue entry expects the source ISO at:
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```text
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/srv/pxe/http/images/systemrescue.iso
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```
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The `stage-systemrescue.service` oneshot extracts that ISO into:
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```text
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/srv/pxe/http/systemrescue
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```
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The rescue menu entry then chains `http://192.168.2.247/systemrescue.ipxe`,
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which loads the SystemRescue kernel and initramfs from the extracted tree and
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uses `archiso_http_srv` to fetch the squashfs payload over HTTP.
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## Validation
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Safe evaluation check:
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```bash
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nix eval .#nixosConfigurations.proxmox-pxe-boot.config.system.build.toplevel.drvPath --raw
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```
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After deployment by an operator, basic service checks are:
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```bash
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curl http://pxe-boot/boot.ipxe
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curl http://pxe-boot/menu.ipxe
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curl http://pxe-boot/systemrescue.ipxe
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curl -I http://pxe-boot/systemrescue/sysresccd/boot/x86_64/vmlinuz
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curl -I http://pxe-boot/systemrescue/sysresccd/boot/x86_64/sysresccd.img
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```
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During a successful BIOS chainload, TFTP should deliver `undionly.kpxe` once,
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then nginx should log requests for `/boot.ipxe` and `/menu.ipxe`. Repeated TFTP
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downloads of `undionly.kpxe` indicate the iPXE stage is still not reaching the
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HTTP chain.
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