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beatzaplentyandClaude Sonnet 5
f0fae441ca
Check NixOS configurations / eval-hosts (push) Failing after 11m55s
Adds debian@surface's existing SSH key (already used as its admin key elsewhere in this repo) to vars.remoteBuilderAuthorizedKeys so nix-cache will accept it as a distributed-build client once deployed. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01La55Nsss8jZ7ZuzUV9mfot
103 lines
3.0 KiB
Markdown
103 lines
3.0 KiB
Markdown
# pxe-boot
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The `pxe-boot` host serves HTTP boot assets for iPXE clients.
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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/nixos
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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/nixos`.
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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 installer
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- SystemRescue environment
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- iPXE shell
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- Reboot
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The NixOS installer entry chain-loads `/srv/pxe/http/nixos/netboot.ipxe`,
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which is nixpkgs' own generated netboot iPXE script (correct `init=`/`initrd=`
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kernel parameters included) rather than a hand-rolled boot line — that script
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in turn expects its kernel/initrd siblings in the same directory. All three
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files (`bzImage`, `initrd`, `netboot.ipxe`) are built from this flake's own
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`modules/installer/iso.nix` netboot image (the same one `nix build .#pxe`
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produces) and staged automatically by
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`modules/pxe-boot/stage-installer-artifacts.nix` via `systemd.tmpfiles.rules`
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— no manual operator step required.
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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.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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