server: auto-create tank ZFS pool on first boot if data disk is blank

A fresh proxmox-server deploy has a blank scsi1 disk, so zfs-import-tank.service spun 60 s then failed with no pool found. Add zfs-init-tank.service that runs before the import: exits immediately if the pool already exists, imports it if it exists but isn't imported yet, or creates it on /dev/disk/by-id/scsi-*drive-scsi1 (Proxmox's virtio-scsi naming for the second disk) with all required NFS datasets if the disk is blank. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Merge branch 'main' of https://gitea.lan.ddnsgeek.com/beatzaplenty/nixos
2026-07-24 06:13:58 +10:00 · 2026-07-24 05:39:18 +10:00 · 2026-07-24 05:38:30 +10:00 · 2026-07-23 02:27:52 +00:00 · 2026-07-23 11:05:51 +10:00 · 2026-07-23 00:40:36 +00:00
15 changed files with 477 additions and 231 deletions
@@ -164,13 +164,39 @@ before committing.

 Beyond `codex-setup.sh`/`codex-maintenance.sh` above, `scripts/` is
 organized by purpose: `scripts/secrets/` (sops/age + SSH host-key
-management), `scripts/proxmox/` (Proxmox deployment), `scripts/lib/`
-(shared helpers, sourced by the scripts below — not run directly), and a
-handful of repo-wide scripts left at the top level (`env.sh`,
-`bump-nixpkgs-release.sh`, plus `codex-setup.sh`/`codex-maintenance.sh`
-above). When adding a new script, put it in the matching subfolder rather
-than the top level, and if it duplicates logic another script already has,
-lift the shared part into `scripts/lib/` instead of copying it.
+management), `scripts/proxmox/` (Proxmox deployment), `scripts/installer/`
+(the auto-installer's own shell script, templated into the image — see
+below), `scripts/lib/` (shared helpers, sourced by the scripts below — not
+run directly), and a handful of repo-wide scripts left at the top level
+(`env.sh`, `bump-nixpkgs-release.sh`, plus `codex-setup.sh`/
+`codex-maintenance.sh` above). When adding a new script, put it in the
+matching subfolder rather than the top level, and if it duplicates logic
+another script already has, lift the shared part into `scripts/lib/`
+instead of copying it.
+
+### `scripts/installer/`
+
+- `scripts/installer/auto-install.sh` — the interactive install script
+  baked into the auto-installer image (see `docs/auto-installer.md`), kept
+  as a real, version-controlled shell file rather than inline in
+  `modules/installer/common.nix`'s Nix. It sources `scripts/env.sh` itself
+  for `LAN_DOMAIN` (`export LAN_DOMAIN`/`: "${LAN_DOMAIN:=...}"`, matching
+  `variables.nix`'s `lanDomain` — manually kept in sync, same pattern as
+  `NIX_CACHE_HOST` mirroring `nixCacheHost`), rather than Nix-level string
+  substitution — that's what makes it work identically whether run
+  straight from a git checkout or from inside the built installer image.
+  `common.nix` bakes `scripts/env.sh` in alongside it at a matching
+  relative path (`/etc/nixos-installer/env.sh` next to
+  `/etc/nixos-installer/installer/auto-install.sh`) so the script's own
+  `source "$(dirname ...)/../env.sh"` line resolves the same way in both
+  contexts — this is also why it's invoked from
+  `/etc/nixos-installer/installer/auto-install.sh` rather than a flat
+  `/etc/auto-install.sh`. `#!/usr/bin/env bash`, not
+  `#!/run/current-system/sw/bin/bash`: the latter only resolves on an
+  already-activated NixOS system, breaking the checked-out-file case
+  entirely (confirmed live: "cannot execute: required file not found" on
+  a non-NixOS box); `/usr/bin/env` is reliably present on both NixOS
+  (`environment.usrbinenv`'s own default) and any normal Linux distro.

 ### `scripts/secrets/`

@@ -282,8 +308,9 @@ Sourced by the scripts above, never run directly:
 ### Top level

 - `scripts/env.sh` — shared config (`PROXMOX_HOST`, storage pool, bridge,
-  default cores/memory) sourced by `create-proxmox-resource.sh`. Add new
-  cross-script config here instead of duplicating it per-script.
+  default cores/memory, `NIX_CACHE_HOST`, `LAN_DOMAIN`) sourced by
+  `create-proxmox-resource.sh` and `scripts/installer/auto-install.sh`. Add
+  new cross-script config here instead of duplicating it per-script.
 - `scripts/bump-nixpkgs-release.sh` — bumps `flake.nix`'s `nixpkgs.url`/
  `home-manager.url` in place. Exists because flake input URLs can't
  reference `variables.nix` (confirmed empirically — `nix flake metadata`
@@ -8,10 +8,13 @@ lives here.
 The installer provides a small NixOS install environment (ISO, or the same
 image netbooted via PXE) with SSH access, Git support, and an interactive
 installation script.
-Logging in as any user (root or `nixos`) runs `/etc/auto-install.sh`,
-discovers available hosts from this same flake, lets the operator choose a
-target, applies that host's Disko storage configuration, installs NixOS, and
-reboots.
+Logging in as any user (root or `nixos`) runs
+`/etc/nixos-installer/installer/auto-install.sh` (the same file as
+`scripts/installer/auto-install.sh` in this repo — see "Installer process"
+below for why it's baked in at that path rather than a flat
+`/etc/auto-install.sh`), discovers available hosts from this same flake,
+lets the operator choose a target, applies that host's Disko storage
+configuration, installs NixOS, and reboots.

 **This applies to every `nixosConfigurations` target except `lxc-*` hosts —
 see "LXC hosts" immediately below for why those are different.**
@@ -192,6 +195,10 @@ default.
 `auto-install.sh` still supports the older manual path as a fallback: if a
 host's key isn't baked in (`/etc/host-keys`), it checks `/root/host-keys`
 next, where you can `scp` a key in after boot, same as before this migration.
+If neither has it and the script is running interactively (an actual
+operator at the other end of stdin, not an unattended run), it prompts for
+an arbitrary directory to check (a mounted USB stick, another filesystem,
+etc.) and copies the key pair into `/root/host-keys` from there if found.

 ## Storage

@@ -217,7 +224,21 @@ entirely (see "LXC hosts" above), so it never reaches this code path.

 ## Installer process

-`/etc/auto-install.sh`:
+`scripts/installer/auto-install.sh` is a real, version-controlled shell
+script — not an inline Nix string. It sources `scripts/env.sh` for
+`LAN_DOMAIN` itself (same as every other script in `scripts/`), so it
+behaves identically whether it's run straight from a git checkout (e.g.
+manually, from a stock NixOS ISO that isn't this repo's own installer
+image) or from inside the built installer image. That's also why it's
+baked in at `/etc/nixos-installer/installer/auto-install.sh` rather than a
+flat `/etc/auto-install.sh` — `modules/installer/common.nix` bakes
+`scripts/env.sh` in alongside it at `/etc/nixos-installer/env.sh`,
+preserving the same relative layout (`installer/auto-install.sh` ->
+`../env.sh`) the checked-out repo has, so the script's own
+`source ".../env.sh"` line resolves correctly in both places without any
+Nix-level templating.
+
+Once running, it:

 1. Queries `nixosConfigurations` from this flake over the network (`git+https://<lanDomain>/beatzaplenty/nixos.git`) — this happens at *install* time, not build time, so a generic installer image always sees whatever hosts are currently committed, without needing a rebuild.
 2. Presents them as a menu; confirms the choice.
@@ -19,11 +19,14 @@
      nextcloud-client
      #    vscode
      chromium
+      claude-code
+      fish
    ];

    # Optional: set environment vars
    sessionVariables = {
      EDITOR = "vim";
+      SOPS_AGE_KEY_FILE = "/home/nixos/Nextcloud/Filing Cabinet/keys/nixos-sops-age-key-txt";
    };

    file = {
@@ -18,7 +18,7 @@
  ];

  boot.loader.grub.useOSProber = true;
-
+programs.direnv.enable = true;
  services = {
    xserver = {
      enable = true;
@@ -1,12 +1,74 @@
-{ vars, lib, ... }:
+{ vars, lib, pkgs, ... }:

+let
+  poolName = lib.removePrefix "/" vars.storageRoot;
+
+  # For each NFS share subpath, generate every ancestor path so ZFS datasets
+  # are created parent-first.  e.g. "docker/config" → ["docker" "docker/config"]
+  ancestors = path:
+    let parts = lib.splitString "/" path;
+    in lib.imap1 (i: _: lib.concatStringsSep "/" (lib.take i parts)) parts;
+
+  poolDatasets = lib.unique (
+    lib.concatMap (share: ancestors share.subpath) (lib.attrValues vars.nfsShares)
+  );
+in
 {
  imports = [
    ../beszel/enable-agent.nix
    ../services/zfs/enable-service.nix
  ];

-  boot.zfs.extraPools = [ (lib.removePrefix "/" vars.storageRoot) ];
+  boot.zfs.extraPools = [ poolName ];
+
+  # On a fresh image deploy the data disk (scsi1) starts blank — no pool
+  # exists yet, so zfs-import-tank.service would spin for 60 s and fail.
+  # This service runs first: if the pool is already present it exits instantly;
+  # otherwise it creates it (with all required datasets) so the standard
+  # import service finds it ready on the very first boot.
+  systemd.services."zfs-init-${poolName}" = {
+    description = "Initialize '${poolName}' ZFS pool on first boot if not present";
+    wantedBy = [ "zfs-import-${poolName}.service" ];
+    before = [ "zfs-import-${poolName}.service" ];
+    after = [ "systemd-udev-settle.service" ];
+    unitConfig.DefaultDependencies = false;
+    serviceConfig = {
+      Type = "oneshot";
+      RemainAfterExit = true;
+    };
+    path = [ pkgs.zfs_unstable ];
+    script = ''
+      # Already imported — nothing to do.
+      if zpool list "${poolName}" >/dev/null 2>&1; then
+        exit 0
+      fi
+
+      # Pool exists on a device but not yet imported — let the standard
+      # zfs-import-${poolName}.service handle it normally.
+      if zpool import -d /dev/disk/by-id -N "${poolName}" 2>/dev/null; then
+        exit 0
+      fi
+
+      # No pool found at all.  Create it on the Proxmox data disk (scsi1),
+      # which appears as /dev/disk/by-id/scsi-*drive-scsi1 inside the VM.
+      DATA_DISK=""
+      for candidate in /dev/disk/by-id/scsi-*drive-scsi1; do
+        [[ "$candidate" == *-part* ]] && continue
+        [ -b "$candidate" ] && DATA_DISK="$candidate" && break
+      done
+
+      if [ -z "$DATA_DISK" ]; then
+        echo "zfs-init-${poolName}: no data disk found (expected /dev/disk/by-id/scsi-*drive-scsi1)" >&2
+        exit 1
+      fi
+
+      echo "zfs-init-${poolName}: creating pool on $DATA_DISK"
+      zpool create -f "${poolName}" "$DATA_DISK"
+      ${lib.concatMapStrings (ds: ''
+        zfs create "${poolName}/${ds}"
+      '') poolDatasets}
+    '';
+  };

  systemd.services.nfs-server = {
    after = [ "zfs-mount.service" ];
@@ -31,6 +31,7 @@
    btop
    git
    gcr
+    jq
  ];

  # Secrets shared by every host, decrypted at activation via each host's
@@ -76,6 +77,7 @@
    openssh.authorizedKeys.keys = [
      vars.adminSshKey
      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICMJhrfFayLBG+gWtO6oAvgambw5nWWgztiTFEaaaVRH debian@surface"
+      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIGygkCljN6uKpdJbHTOQtn8ZnH+wKXDLAwrDFbLrE/65 nixos@nixos"
    ];
  };

@@ -45,142 +45,23 @@
      disko
    ];

-    # Write auto-install script to /root
-    etc."auto-install.sh" = {
-      text = ''
-            #!/run/current-system/sw/bin/bash
-            set -eux
-
-            set -euo pipefail
-
-        export FLAKE_BASE_URL="git+https://${vars.lanDomain}/beatzaplenty/nixos.git"
-
-        echo "Fetching available NixOS hosts from flake..."
-        # Two categories deliberately excluded from the menu:
-        #   lxc-*     — these build a config.system.build.tarball meant for
-        #               `pct restore` on Proxmox directly, not an install.
-        #               Running nixos-install against one here would
-        #               bind-mount / onto /mnt and then refuse to touch the
-        #               filesystem it's currently running on — see
-        #               docs/auto-installer.md.
-        #   installer — this *is* the installer image's own flake target,
-        #               not a deployable host; "installing" it means
-        #               nixos-install-ing a copy of the installer into
-        #               itself.
-        mapfile -t options < <(
-          nix eval --json --no-use-registries --no-accept-flake-config --extra-experimental-features "flakes nix-command" \
-            "''${FLAKE_BASE_URL}#nixosConfigurations" \
-            --apply builtins.attrNames \
-          | jq -r '.[]
-              | select(startswith("lxc-") | not)
-              | select(. != "installer")'
-        )
-
-        if [[ ''${#options[@]} -eq 0 ]]; then
-          echo "ERROR: No NixOS hosts found in ''${FLAKE_BASE_URL}#nixosConfigurations" >&2
-          exit 1
-        fi
-
-        echo "Note: lxc-* targets aren't installed this way — build them with"
-        echo "  nix build .#nixosConfigurations.<name>.config.system.build.tarball"
-        echo "and 'pct restore' the result on Proxmox directly. See docs/auto-installer.md."
-
-        echo "Choose the flake profile to install:"
-        select choice in "''${options[@]}"; do
-          if [[ -n "$choice" ]]; then
-            echo "You selected: $choice"
-            break
-          else
-            echo "Invalid selection. Try again."
-          fi
-        done
-
-        echo "Starting install with flake: ''${FLAKE_BASE_URL}#''${choice}"
-
-        # Optional: confirm before proceeding
-        read -rp "Proceed with installation? (y/N): " confirm
-        if [[ ! "$confirm" =~ ^[Yy]$ ]]; then
-          echo "Aborted."
-          exit 1
-        fi
-
-        # A nix-cache host is *the* substituter/remote-builder for every other
-        # host once installed (its own config explicitly excludes itself from
-        # using either — see buildType != "nix-cache" in the nixos flake.nix).
-        # Installing one shouldn't depend on a nix-cache substituter either,
-        # for the same reason — plus in practice "nix-cache" only resolves over
-        # Tailscale, which a fresh installer environment was never connected to
-        # anyway, so it's dead weight even for non-nix-cache installs until
-        # that's sorted out. Override it away here specifically for nix-cache
-        # targets to keep install-time behaviour consistent with run-time.
-        nix_extra_opts=()
-        if [[ "''${choice}" == *-nix-cache ]]; then
-            echo "Installing a nix-cache host — skipping the nix-cache substituter."
-            nix_extra_opts+=(--option substituters "https://cache.nixos.org/")
-        fi
-
-        # Every host reachable through this menu has a Disko config (lxc-*
-        # is filtered out above, and is the only category that doesn't —
-        # see docs/auto-installer.md), so this can run unconditionally: no
-        # need to probe the flake first and branch on whether Disko applies.
-        disko --mode destroy,format,mount \
-            --flake "''${FLAKE_BASE_URL}#''${choice}" "''${nix_extra_opts[@]}" --yes-wipe-all-disks
-
-        # sops-nix derives this host's decryption key from its own SSH host key
-        # at *activation* time, which runs before systemd would otherwise
-        # generate one on first boot. Without pre-seeding it here, secrets
-        # (including the login password) fail to decrypt on first boot.
-        # Generate the key with scripts/secrets/prepare-host-key.sh first.
-        #
-        # Two places a key can come from, checked in order:
-        #   /etc/host-keys  — baked into this image at build time (see
-        #                      modules/installer/host-keys.nix; only present
-        #                      if built with NIXOS_HOST_KEYS_DIR set)
-        #   /root/host-keys — scp'd in manually after boot (older fallback,
-        #                      still supported for images built without keys)
-        mkdir -p /root/host-keys
-        if [[ -f "/etc/host-keys/''${choice}_ssh_host_ed25519_key" ]]; then
-            echo "Found baked-in SSH host key for ''${choice}, installing to target..."
-            install -D -m 0600 "/etc/host-keys/''${choice}_ssh_host_ed25519_key" /mnt/etc/ssh/ssh_host_ed25519_key
-            install -D -m 0644 "/etc/host-keys/''${choice}_ssh_host_ed25519_key.pub" /mnt/etc/ssh/ssh_host_ed25519_key.pub
-        elif [[ -f "/root/host-keys/''${choice}_ssh_host_ed25519_key" ]]; then
-            echo "Found pre-seeded SSH host key for ''${choice}, installing to target..."
-            install -D -m 0600 "/root/host-keys/''${choice}_ssh_host_ed25519_key" /mnt/etc/ssh/ssh_host_ed25519_key
-            install -D -m 0644 "/root/host-keys/''${choice}_ssh_host_ed25519_key.pub" /mnt/etc/ssh/ssh_host_ed25519_key.pub
-        else
-            echo "WARNING: no SSH host key found for ''${choice} (checked /etc/host-keys and /root/host-keys)"
-            echo "sops-nix secrets (including the login password) will NOT decrypt on first boot."
-            echo "Run scripts/secrets/prepare-host-key.sh for host ''${choice} on your admin workstation first,"
-            echo "then either rebuild this image with NIXOS_HOST_KEYS_DIR set, or scp the result to"
-            echo "/root/host-keys/ on this machine."
-            read -rp "Continue without a pre-seeded key anyway? (y/N): " skip_key
-            if [[ ! "$skip_key" =~ ^[Yy]$ ]]; then
-                echo "Aborted."
-                exit 1
-            fi
-        fi
-
-        mkdir -p /mnt/install-tmp
-        export TMPDIR=/mnt/install-tmp
-
-        nixos-install \
-            --flake "''${FLAKE_BASE_URL}#''${choice}" \
-            "''${nix_extra_opts[@]}" \
-            --no-root-password
-
-
-            rm -rf /mnt/install-tmp
-            # Redundant copy of the host's private key — the real one is now at
-            # /etc/ssh/ssh_host_ed25519_key. Nothing NixOS-managed ever cleans this
-            # up on its own since it was written imperatively, not declaratively.
-            rm -rf /root/host-keys
-            sleep 10
-            reboot
-      '';
+    # Auto-install script, kept as a real, version-controlled shell file at
+    # scripts/installer/auto-install.sh rather than an inline Nix string.
+    # It sources scripts/env.sh itself (for LAN_DOMAIN, same as every other
+    # script in this repo) rather than relying on Nix-level templating, so
+    # it behaves identically whether it's run straight from a git checkout
+    # or from here -- baking scripts/env.sh in alongside it at a matching
+    # relative path (installer/auto-install.sh -> ../env.sh) is what makes
+    # that resolve correctly in both places.
+    etc = {
+      "nixos-installer/env.sh".source = ../../scripts/env.sh;

+      "nixos-installer/installer/auto-install.sh" = {
+        source = ../../scripts/installer/auto-install.sh;
        mode = "0755";
      };
    };
+  };

  programs.git.enable = true;

@@ -192,7 +73,7 @@
  # file-copying/chown.
  programs.bash.loginShellInit = ''
    if [ -n "$PS1" ] && [ ! -e "$HOME/.auto_install_ran" ]; then
-      sudo /etc/auto-install.sh
+      sudo /etc/nixos-installer/installer/auto-install.sh
      touch "$HOME/.auto_install_ran"
    fi
  '';
@@ -25,4 +25,14 @@
    enable = true;
    enable32Bit = true;
  };
+
+  # The systemd-based initrd (default here since this host has a ZFS root --
+  # see modules/disko/baremetal.nix) locks the root account by default, so
+  # sulogin refuses to hand over a shell if something in the initrd (e.g.
+  # the ZFS pool import) fails and it drops to emergency mode -- confirmed
+  # live: it just loops re-entering the target instead of prompting. This
+  # only affects the pre-switch-root initrd shell, not the installed
+  # system's own login, and is worth the tradeoff on a box already reachable
+  # at the physical console.
+  boot.initrd.systemd.emergencyAccess = true;
 }
@@ -68,6 +68,7 @@ cat > "$HOME/.config/nix/nix.conf" <<'EOF'
 experimental-features = nix-command flakes
 accept-flake-config = false
 warn-dirty = false
+build-users-group =
 EOF

 echo "Nix version:"
@@ -22,7 +22,7 @@
 : "${PVE1_HOST:=pve1.sweet.home}"
 : "${PVE_TEST_HOST:=pve-test.sweet.home}"
 : "${PROXMOX_HOST:=$PVE1_HOST}"
-: "${PROXMOX_SSH_USER:=root}"
+: "${PROXMOX_SSH_USER:=wayne}"

 # Where this flake repo lives on the Proxmox node itself.
 # scripts/proxmox/create-proxmox-resource.sh builds images directly on the node
@@ -30,7 +30,7 @@
 # (from this checkout's own `origin` remote) the first time it doesn't
 # find it, installing build tooling via scripts/codex-setup.sh, then
 # `git pull`s it before every subsequent build.
-: "${PROXMOX_REMOTE_REPO_DIR:=/root/nixos}"
+: "${PROXMOX_REMOTE_REPO_DIR:=/home/${PROXMOX_SSH_USER}/nixos}"

 # Storage pool names -- Proxmox's own stock-install defaults, but this
 # varies a lot by setup (ZFS pool name, custom LVM-thin volume, etc.).
@@ -82,6 +82,12 @@ export PVE1_HOST PVE_TEST_HOST PROXMOX_HOST PROXMOX_SSH_USER PROXMOX_STORAGE \
 : "${NIX_CACHE_HOST:=nix-cache}"
 export NIX_CACHE_HOST

+# Matches variables.nix's lanDomain (the Gitea host this flake's own repo
+# is served from -- see scripts/installer/auto-install.sh's FLAKE_BASE_URL)
+# -- update both if it ever changes.
+: "${LAN_DOMAIN:=gitea.lan.ddnsgeek.com}"
+export LAN_DOMAIN
+
 # nix_extra_opts: call as a plain statement (NOT inside $(...)/<(...) --
 # that forks a subshell, and the whole point is exporting a decision back
 # into *this* shell) to populate the global NIX_OPTS array with whatever
@@ -0,0 +1,206 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -p jq disko nixos-install-tools zfs
+# shellcheck shell=bash
+# The only genuinely external tools this script calls directly: `jq`
+# (parsing the `nix eval` host list), `disko`/`nixos-install` (the
+# install itself), and `zpool` (exporting a ZFS root pool before reboot,
+# see the comment above that call below). Everything disko shells out to
+# internally (parted/sgdisk/mkfs.*/zfs/...) is self-contained -- disko's
+# own generated scripts hardcode absolute Nix store paths for those, they
+# don't rely on this script's PATH at all (confirmed by inspecting a
+# generated system.build.formatScript). The built installer image
+# (modules/installer/common.nix, plus the upstream
+# installation-cd-minimal.nix it imports via iso.nix) already has all
+# four in environment.systemPackages, so this nix-shell wrapper is a
+# fast no-op there; it's what makes the script also work standalone
+# (e.g. run directly from a checkout on a stock ISO), where they aren't
+# guaranteed.
+set -eux
+
+set -euo pipefail
+
+# shellcheck source=../env.sh
+source "$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)/env.sh"
+
+export FLAKE_BASE_URL="git+https://${LAN_DOMAIN}/beatzaplenty/nixos.git"
+
+echo "Fetching available NixOS hosts from flake..."
+# Two categories deliberately excluded from the menu:
+#   lxc-*     — these build a config.system.build.tarball meant for
+#               `pct restore` on Proxmox directly, not an install.
+#               Running nixos-install against one here would
+#               bind-mount / onto /mnt and then refuse to touch the
+#               filesystem it's currently running on — see
+#               docs/auto-installer.md.
+#   installer — this *is* the installer image's own flake target,
+#               not a deployable host; "installing" it means
+#               nixos-install-ing a copy of the installer into
+#               itself.
+mapfile -t options < <(
+  nix eval --json --no-use-registries --no-accept-flake-config --extra-experimental-features "flakes nix-command" \
+    "${FLAKE_BASE_URL}#nixosConfigurations" \
+    --apply builtins.attrNames \
+  | jq -r '.[]
+      | select(startswith("lxc-") | not)
+      | select(. != "installer")'
+)
+
+if [[ ${#options[@]} -eq 0 ]]; then
+  echo "ERROR: No NixOS hosts found in ${FLAKE_BASE_URL}#nixosConfigurations" >&2
+  exit 1
+fi
+
+echo "Note: lxc-* targets aren't installed this way — build them with"
+echo "  nix build .#nixosConfigurations.<name>.config.system.build.tarball"
+echo "and 'pct restore' the result on Proxmox directly. See docs/auto-installer.md."
+
+echo "Choose the flake profile to install:"
+select choice in "${options[@]}"; do
+  if [[ -n "$choice" ]]; then
+    echo "You selected: $choice"
+    break
+  else
+    echo "Invalid selection. Try again."
+  fi
+done
+
+echo "Starting install with flake: ${FLAKE_BASE_URL}#${choice}"
+
+# Optional: confirm before proceeding
+read -rp "Proceed with installation? (y/N): " confirm
+if [[ ! "$confirm" =~ ^[Yy]$ ]]; then
+  echo "Aborted."
+  exit 1
+fi
+
+# A nix-cache host is *the* substituter/remote-builder for every other
+# host once installed (its own config explicitly excludes itself from
+# using either — see buildType != "nix-cache" in the nixos flake.nix).
+# Installing one shouldn't depend on a nix-cache substituter either,
+# for the same reason — plus in practice "nix-cache" only resolves over
+# Tailscale, which a fresh installer environment was never connected to
+# anyway, so it's dead weight even for non-nix-cache installs until
+# that's sorted out. Override it away here specifically for nix-cache
+# targets to keep install-time behaviour consistent with run-time.
+nix_extra_opts=()
+if [[ "${choice}" == *-nix-cache ]]; then
+    echo "Installing a nix-cache host — skipping the nix-cache substituter."
+    nix_extra_opts+=(--option substituters "https://cache.nixos.org/")
+fi
+
+# Every host reachable through this menu has a Disko config (lxc-*
+# is filtered out above, and is the only category that doesn't —
+# see docs/auto-installer.md), so this can run unconditionally: no
+# need to probe the flake first and branch on whether Disko applies.
+disko --mode destroy,format,mount \
+    --flake "${FLAKE_BASE_URL}#${choice}" "${nix_extra_opts[@]}" --yes-wipe-all-disks
+
+# sops-nix derives this host's decryption key from its own SSH host key
+# at *activation* time, which runs before systemd would otherwise
+# generate one on first boot. Without pre-seeding it here, secrets
+# (including the login password) fail to decrypt on first boot.
+# Generate the key with scripts/secrets/prepare-host-key.sh first.
+#
+# Two places a key can come from, checked in order:
+#   /etc/host-keys  — baked into this image at build time (see
+#                      modules/installer/host-keys.nix; only present
+#                      if built with NIXOS_HOST_KEYS_DIR set)
+#   /root/host-keys — scp'd in manually after boot (older fallback,
+#                      still supported for images built without keys)
+mkdir -p /root/host-keys
+if [[ -f "/etc/host-keys/${choice}_ssh_host_ed25519_key" ]]; then
+    echo "Found baked-in SSH host key for ${choice}, installing to target..."
+    install -D -m 0600 "/etc/host-keys/${choice}_ssh_host_ed25519_key" /mnt/etc/ssh/ssh_host_ed25519_key
+    install -D -m 0644 "/etc/host-keys/${choice}_ssh_host_ed25519_key.pub" /mnt/etc/ssh/ssh_host_ed25519_key.pub
+elif [[ -f "/root/host-keys/${choice}_ssh_host_ed25519_key" ]]; then
+    echo "Found pre-seeded SSH host key for ${choice}, installing to target..."
+    install -D -m 0600 "/root/host-keys/${choice}_ssh_host_ed25519_key" /mnt/etc/ssh/ssh_host_ed25519_key
+    install -D -m 0644 "/root/host-keys/${choice}_ssh_host_ed25519_key.pub" /mnt/etc/ssh/ssh_host_ed25519_key.pub
+else
+    # Third place a key can come from: an arbitrary path the operator
+    # points at interactively (e.g. a USB stick, a mount from another
+    # machine) -- only offered when there's an actual human at the other
+    # end of stdin to ask, never in a non-interactive run.
+    key_copied=0
+    if [[ -t 0 ]]; then
+        echo "No SSH host key found for ${choice} (checked /etc/host-keys and /root/host-keys)."
+        read -rp "Path to a directory containing ${choice}_ssh_host_ed25519_key(.pub) (blank to skip): " key_src_dir
+        if [[ -n "$key_src_dir" && -f "${key_src_dir}/${choice}_ssh_host_ed25519_key" && -f "${key_src_dir}/${choice}_ssh_host_ed25519_key.pub" ]]; then
+            cp "${key_src_dir}/${choice}_ssh_host_ed25519_key" "${key_src_dir}/${choice}_ssh_host_ed25519_key.pub" /root/host-keys/
+            key_copied=1
+        elif [[ -n "$key_src_dir" ]]; then
+            echo "WARNING: ${choice}_ssh_host_ed25519_key(.pub) not found in ${key_src_dir}."
+        fi
+    fi
+
+    if [[ "$key_copied" -eq 1 ]]; then
+        echo "Copied SSH host key for ${choice} from ${key_src_dir}, installing to target..."
+        install -D -m 0600 "/root/host-keys/${choice}_ssh_host_ed25519_key" /mnt/etc/ssh/ssh_host_ed25519_key
+        install -D -m 0644 "/root/host-keys/${choice}_ssh_host_ed25519_key.pub" /mnt/etc/ssh/ssh_host_ed25519_key.pub
+    else
+        echo "WARNING: no SSH host key found for ${choice} (checked /etc/host-keys and /root/host-keys)"
+        echo "sops-nix secrets (including the login password) will NOT decrypt on first boot."
+        echo "Run scripts/secrets/prepare-host-key.sh for host ${choice} on your admin workstation first,"
+        echo "then either rebuild this image with NIXOS_HOST_KEYS_DIR set, scp the result to"
+        echo "/root/host-keys/ on this machine, or point at it when prompted above."
+        read -rp "Continue without a pre-seeded key anyway? (y/N): " skip_key
+        if [[ ! "$skip_key" =~ ^[Yy]$ ]]; then
+            echo "Aborted."
+            exit 1
+        fi
+    fi
+fi
+
+mkdir -p /mnt/install-tmp
+export TMPDIR=/mnt/install-tmp
+
+nixos-install \
+    --flake "${FLAKE_BASE_URL}#${choice}" \
+    "${nix_extra_opts[@]}" \
+    --no-root-password
+
+
+    rm -rf /mnt/install-tmp
+    # Redundant copy of the host's private key — the real one is now at
+    # /etc/ssh/ssh_host_ed25519_key. Nothing NixOS-managed ever cleans this
+    # up on its own since it was written imperatively, not declaratively.
+    rm -rf /root/host-keys
+
+    # disko's --mode ...,mount left any ZFS root pool imported (that's what
+    # let nixos-install write into /mnt). If we reboot with it still
+    # imported, it isn't just "not exported" -- it's stamped with *this*
+    # live installer environment's hostid, which almost never matches the
+    # target's own networking.hostId (see hosts/*/host.nix; the installer
+    # itself sets none). modules/services/zfs/enable-service.nix and
+    # modules/common/configuration.nix both set boot.zfs.forceImportRoot =
+    # false deliberately (the safe option per that setting's own docs), so
+    # the freshly-installed system's first real boot sees a pool "in use by
+    # another system" and refuses to import it without -f -- which is what
+    # makes boot stall waiting on the ZFS import. Exporting here (a no-op
+    # if the chosen host has no ZFS root, e.g. proxmox-*/linode-*) clears
+    # that in-use state so the next import, from any hostid, succeeds.
+    #
+    # Anything still mounted under /mnt -- nixos-install's own leftover
+    # chroot bind mounts for running the target's activation script
+    # (/mnt/dev, /mnt/proc, /mnt/sys, /mnt/run), and disko's own /mnt/boot
+    # ESP mount (modules/disko/baremetal.nix) -- blocks ZFS from unmounting
+    # its root dataset at /mnt, the same way any nested mount blocks
+    # unmounting its parent. Confirmed live: zpool export failed with
+    # "cannot unmount '/mnt': pool or dataset busy" even after handling the
+    # chroot mounts alone, because /mnt/boot was still mounted too. Because
+    # of this script's `set -e`, that killed the script before it ever
+    # reached reboot, silently defeating the whole point of exporting first.
+    # Unmounting everything under /mnt up front (recursively, so nested
+    # mounts like /mnt/dev/pts come along for free) sidesteps needing to
+    # enumerate every mount disko/nixos-install might leave behind.
+    if mountpoint -q /mnt; then
+        umount -R /mnt
+    fi
+
+    if [[ -n "$(zpool list -H -o name 2>/dev/null)" ]]; then
+        echo "Exporting ZFS pool(s) before reboot..."
+        zpool export -a
+    fi
+
+    sleep 10
+    reboot
@@ -6,27 +6,31 @@
 #
 # This is the non-NixOS equivalent of modules/nix-cache/client.nix +
 # modules/nix-cache/remote-builder-client.nix -- those two only apply to
-# hosts built from this flake. A plain Debian box with Nix installed
-# (single- or multi-user install, nix-daemon running) has no NixOS module
-# system to pick that config up, so this edits /etc/nix/nix.conf by hand
-# instead. Run this ON the target Debian machine, as root.
+# hosts built from this flake. A plain Debian box with Nix installed has no
+# NixOS module system to pick that config up, so this edits nix.conf by hand.
+#
+# Two modes depending on who runs it:
+#
+#   root (multi-user / daemon install):
+#     Writes /etc/nix/nix.conf, /etc/ssh/ssh_known_hosts, restarts nix-daemon.
+#     Requires /etc/nix/nix.conf to already exist (i.e. nix-daemon is set up).
+#     Run as: sudo ./configure-nix-cache-client.sh [options]
+#
+#   non-root (single-user install):
+#     Writes ~/.config/nix/nix.conf, ~/.ssh/known_hosts. No daemon to restart.
+#     Run as: ./configure-nix-cache-client.sh [options]
 #
 # The values below mirror variables.nix / modules/nix-cache/client.nix in
 # this repo -- update both if nix-cache is ever rebuilt with a new host
 # key or the cache signing key is rotated (see docs/nix-cache.md).
 #
-# REMOTE_BUILDER_KEY defaults to this machine's own default root SSH
-# identity (matches modules/nix-cache/remote-builder-client.nix's
-# convention for real NixOS clients: authenticate as nixremote with the
-# host's own default key, added individually to
-# vars.remoteBuilderAuthorizedKeys, rather than a separately-named or
-# shared keypair) -- generate one with
-# `ssh-keygen -t ed25519 -N '' -f /root/.ssh/id_ed25519` if this machine
-# doesn't have one yet, then add its .pub to vars.remoteBuilderAuthorizedKeys
-# and rebuild nix-cache.
+# REMOTE_BUILDER_KEY defaults to the running user's default SSH identity
+# (root: /root/.ssh/id_ed25519, other user: ~/.ssh/id_ed25519). That key
+# must be listed in vars.remoteBuilderAuthorizedKeys in this repo and
+# nix-cache rebuilt before remote building works.
 #
 # Usage:
-#   sudo ./configure-nix-cache-client.sh [--dry-run] [--no-remote-builder] [--no-restart]
+#   ./configure-nix-cache-client.sh [--dry-run] [--no-remote-builder] [--no-restart]
 #
 # Env overrides (defaults match variables.nix):
 #   NIX_CACHE_HOST, NIX_CACHE_HOST_KEY, REMOTE_BUILDER_USER, REMOTE_BUILDER_KEY
@@ -36,17 +40,28 @@ set -euo pipefail
 : "${NIX_CACHE_HOST:=nix-cache}"
 : "${NIX_CACHE_HOST_KEY:=ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPeWgMsdaiz4axT/deFc1+0B5bN+GX/NOeW9bbQ0c/IT lxc-nix-cache}"
 : "${REMOTE_BUILDER_USER:=nixremote}"
-: "${REMOTE_BUILDER_KEY:=/root/.ssh/id_ed25519}"

 CACHE_PUB_KEY="cache.local-1:usoWYanY3Kpq2+kDIS2nhWoLZiRxanmdysdzqCFBHW4="
 FALLBACK_URL="https://cache.nixos.org/"
 FALLBACK_PUB_KEY="cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="

-NIX_CONF="/etc/nix/nix.conf"
-KNOWN_HOSTS="/etc/ssh/ssh_known_hosts"
 MARKER_BEGIN="# BEGIN nix-cache client config (configure-nix-cache-client.sh)"
 MARKER_END="# END nix-cache client config"

+# Mode: root uses system-wide paths and restarts the daemon; non-root uses
+# user-level paths and has no daemon to restart.
+if [[ "$EUID" -eq 0 ]]; then
+  install_mode="multi"
+  NIX_CONF="/etc/nix/nix.conf"
+  KNOWN_HOSTS="/etc/ssh/ssh_known_hosts"
+  : "${REMOTE_BUILDER_KEY:=/root/.ssh/id_ed25519}"
+else
+  install_mode="single"
+  NIX_CONF="${XDG_CONFIG_HOME:-$HOME/.config}/nix/nix.conf"
+  KNOWN_HOSTS="$HOME/.ssh/known_hosts"
+  : "${REMOTE_BUILDER_KEY:=$HOME/.ssh/id_ed25519}"
+fi
+
 dry_run=0
 with_remote_builder=1
 restart_daemon=1
@@ -57,7 +72,7 @@ for arg in "$@"; do
    --no-remote-builder) with_remote_builder=0 ;;
    --no-restart) restart_daemon=0 ;;
    -h|--help)
-      sed -n '2,20p' "$0"
+      sed -n '2,37p' "$0"
      exit 0
      ;;
    *)
@@ -67,21 +82,22 @@ for arg in "$@"; do
  esac
 done

-if [[ "$dry_run" -eq 0 && "$EUID" -ne 0 ]]; then
-  echo "ERROR: must run as root (writes $NIX_CONF and, unless --no-remote-builder, $KNOWN_HOSTS)." >&2
-  exit 1
-fi
-
 if ! command -v nix >/dev/null 2>&1; then
  echo "ERROR: no 'nix' binary on PATH -- install the Nix package manager first." >&2
  exit 1
 fi

-if [[ ! -f "$NIX_CONF" ]]; then
+if [[ "$install_mode" == "multi" && ! -f "$NIX_CONF" ]]; then
  echo "ERROR: $NIX_CONF not found -- expected an existing multi-user Nix install." >&2
  exit 1
 fi

+# Single-user: create the config file if it doesn't exist yet.
+if [[ "$install_mode" == "single" && "$dry_run" -eq 0 ]]; then
+  mkdir -p "$(dirname "$NIX_CONF")"
+  [[ -f "$NIX_CONF" ]] || touch "$NIX_CONF"
+fi
+
 builder_line=""
 if [[ "$with_remote_builder" -eq 1 ]]; then
  if [[ -f "$REMOTE_BUILDER_KEY" ]]; then
@@ -117,7 +133,7 @@ fi
 block="${block}
 $MARKER_END"

-echo "== nix.conf block to install =="
+echo "== nix.conf block to install ($NIX_CONF) =="
 echo "$block"
 echo "================================"

@@ -159,7 +175,8 @@ if [[ "$with_remote_builder" -eq 1 ]]; then
  fi
 fi

-if [[ "$dry_run" -eq 0 && "$restart_daemon" -eq 1 ]]; then
+# Only restart the daemon for multi-user installs -- single-user has no daemon.
+if [[ "$dry_run" -eq 0 && "$restart_daemon" -eq 1 && "$install_mode" == "multi" ]]; then
  if command -v systemctl >/dev/null 2>&1 && systemctl is-active --quiet nix-daemon 2>/dev/null; then
    systemctl restart nix-daemon
    echo "Restarted nix-daemon to pick up the new config."
@@ -193,6 +193,16 @@ done

 ssh_target="${PROXMOX_SSH_USER}@${node}"

+# Proxmox tools (pvesh, qm, pct) require root access to the cluster IPC
+# socket. When SSH-ing as a non-root user with sudo, prefix every remote
+# Proxmox command with sudo.
+sudo_prefix=""
+sudo_display=""
+if [[ "$PROXMOX_SSH_USER" != "root" ]]; then
+  sudo_prefix="sudo"
+  sudo_display="sudo "
+fi
+
 remote() {
  if [[ "$dry_run" -eq 1 ]]; then
    echo "[dry-run] ssh ${ssh_target} -- $*"
@@ -214,10 +224,10 @@ cmd_modify() {

  echo "Looking up VMID ${vmid} on ${node}..."
  local kind current_cores current_memory disk_key
-  if ssh "$ssh_target" "qm status ${vmid}" >/dev/null 2>&1; then
+  if ssh "$ssh_target" "${sudo_prefix} qm status ${vmid}" >/dev/null 2>&1; then
    kind="vm"
    disk_key="scsi0"
-  elif ssh "$ssh_target" "pct status ${vmid}" >/dev/null 2>&1; then
+  elif ssh "$ssh_target" "${sudo_prefix} pct status ${vmid}" >/dev/null 2>&1; then
    kind="lxc"
    disk_key="rootfs"
  else
@@ -225,8 +235,8 @@ cmd_modify() {
    exit 1
  fi

-  local config_cmd="qm config ${vmid}"
-  [[ "$kind" == "lxc" ]] && config_cmd="pct config ${vmid}"
+  local config_cmd="${sudo_prefix} qm config ${vmid}"
+  [[ "$kind" == "lxc" ]] && config_cmd="${sudo_prefix} pct config ${vmid}"
  local current_config
  current_config="$(ssh "$ssh_target" "$config_cmd")"
  current_cores="$(echo "$current_config" | grep -oP '^cores:\s*\K\S+' || echo '?')"
@@ -250,9 +260,9 @@ cmd_modify() {
    exit 1
  fi

-  local set_cmd="qm set"
-  local resize_cmd="qm resize"
-  [[ "$kind" == "lxc" ]] && set_cmd="pct set" && resize_cmd="pct resize"
+  local set_cmd="${sudo_prefix} qm set"
+  local resize_cmd="${sudo_prefix} qm resize"
+  [[ "$kind" == "lxc" ]] && set_cmd="${sudo_prefix} pct set" && resize_cmd="${sudo_prefix} pct resize"

  if [[ -n "$cores" || -n "$memory" ]]; then
    local args=""
@@ -359,14 +369,15 @@ else
  echo
  echo "==> Checking ${node} for an existing VM/CT identified as '${host}'..."
  ssh_check_status=0
-  existing="$(ssh "$ssh_target" bash -s -- "$host" <<'REMOTE_SCRIPT'
+  existing="$(ssh "$ssh_target" bash -s -- "$host" "$sudo_prefix" <<'REMOTE_SCRIPT'
 target="$1"
-for id in $(qm list 2>/dev/null | awk 'NR>1{print $1}'); do
-  n="$(qm config "$id" 2>/dev/null | grep -oP '^name:\s*\K\S+' || true)"
+sudo_pfx="$2"
+for id in $($sudo_pfx qm list 2>/dev/null | awk 'NR>1{print $1}'); do
+  n="$($sudo_pfx qm config "$id" 2>/dev/null | grep -oP '^name:\s*\K\S+' || true)"
  [[ "$n" == "$target" ]] && echo "vm ${id} ${n}"
 done
-for id in $(pct list 2>/dev/null | awk 'NR>1{print $1}'); do
-  n="$(pct config "$id" 2>/dev/null | grep -oP '^hostname:\s*\K\S+' || true)"
+for id in $($sudo_pfx pct list 2>/dev/null | awk 'NR>1{print $1}'); do
+  n="$($sudo_pfx pct config "$id" 2>/dev/null | grep -oP '^hostname:\s*\K\S+' || true)"
  [[ "$n" == "$target" ]] && echo "lxc ${id} ${n}"
 done
 exit 0
@@ -453,12 +464,12 @@ REMOTE_SCRIPT
      if [[ "$kind" == "vm" ]]; then
        # qm destroy has no --force to stop-then-destroy in one call (pct's
        # does) -- stop explicitly first if it's running.
-        if ssh "$ssh_target" "qm status ${id}" 2>/dev/null | grep -q running; then
-          ssh "$ssh_target" "qm stop ${id}"
+        if ssh "$ssh_target" "${sudo_prefix} qm status ${id}" 2>/dev/null | grep -q running; then
+          ssh "$ssh_target" "${sudo_prefix} qm stop ${id}"
        fi
-        ssh "$ssh_target" "qm destroy ${id} --purge 1"
+        ssh "$ssh_target" "${sudo_prefix} qm destroy ${id} --purge 1"
      else
-        ssh "$ssh_target" "pct destroy ${id} --force 1 --purge 1"
+        ssh "$ssh_target" "${sudo_prefix} pct destroy ${id} --force 1 --purge 1"
      fi
    done
  fi
@@ -487,7 +498,7 @@ if [[ -z "$vmid" ]]; then
    vmid="<next-free-vmid>"
    echo "[dry-run] would ask ${node} for the next free VMID (pvesh get /cluster/nextid)"
  else
-    vmid="$(ssh "$ssh_target" "pvesh get /cluster/nextid" | tr -d '[:space:]')"
+    vmid="$(ssh "$ssh_target" "${sudo_prefix} pvesh get /cluster/nextid" | tr -d '[:space:]')"
    echo "Auto-assigned VMID: ${vmid}"
  fi
 else
@@ -501,8 +512,8 @@ if [[ "$dry_run" -eq 0 ]]; then
  # both. Any success here means something is already using this ID --
  # refuse to go anywhere near it. (Reconfiguring an existing resource is
  # --modify's job, not this one's.)
-  if ssh "$ssh_target" "qm status ${vmid}" >/dev/null 2>&1 \
-    || ssh "$ssh_target" "pct status ${vmid}" >/dev/null 2>&1; then
+  if ssh "$ssh_target" "${sudo_prefix} qm status ${vmid}" >/dev/null 2>&1 \
+    || ssh "$ssh_target" "${sudo_prefix} pct status ${vmid}" >/dev/null 2>&1; then
    echo "ERROR: VMID ${vmid} already exists on ${node}. Refusing to touch an" >&2
    echo "existing resource here -- use --modify to reconfigure it, pick a" >&2
    echo "different --vmid, or omit it to auto-assign." >&2
@@ -672,11 +683,11 @@ if [[ "$image_already_remote" -eq 0 && -z "$local_image" ]]; then
      # hands the result to the remote shell to re-split, which would
      # otherwise scatter NIX_EXTRA_OPTS (itself several space-separated,
      # %q-quoted tokens) across the wrong positional parameters below.
-      printf -v remote_cmd 'bash -s -- %q %q %q %q %q' \
-        "$remote_repo_dir" "$flake_target" "$remote_dir" "$remote_filename" "$NIX_EXTRA_OPTS"
+      printf -v remote_cmd 'bash -s -- %q %q %q %q %q %q' \
+        "$remote_repo_dir" "$flake_target" "$remote_dir" "$remote_filename" "$NIX_EXTRA_OPTS" "$sudo_prefix"
      ssh "$ssh_target" "$remote_cmd" <<'REMOTE_SCRIPT'
 set -euo pipefail
-repo_dir="$1"; target="$2"; dest_dir="$3"; dest_name="$4"; nix_extra_opts_str="$5"
+repo_dir="$1"; target="$2"; dest_dir="$3"; dest_name="$4"; nix_extra_opts_str="$5"; sudo_pfx="$6"
 declare -a NIX_OPTS=()
 [[ -n "$nix_extra_opts_str" ]] && eval "NIX_OPTS=(${nix_extra_opts_str})"
 cd "$repo_dir"
@@ -694,23 +705,14 @@ if [[ -z "$built" ]]; then
  echo "ERROR: no tarball found under result-${target}/tarball after build." >&2
  exit 1
 fi
-mkdir -p "$dest_dir"
-cp "$built" "${dest_dir}/${dest_name}"
+$sudo_pfx mkdir -p "$dest_dir"
+$sudo_pfx cp "$built" "${dest_dir}/${dest_name}"
 echo "Built and staged: ${dest_dir}/${dest_name}"
 REMOTE_SCRIPT
      local_image="$remote_path"
      echo "Built on ${node}: ${remote_path}"
    fi
  else
-    # PROXMOX_SSH_USER defaults to root (env.sh), which needs no sudo and
-    # can't assume it's even installed on a minimal node -- only shell out
-    # through sudo when actually running as a non-root SSH user.
-    sudo_prefix="sudo"
-    sudo_display="sudo "
-    if [[ "$PROXMOX_SSH_USER" == "root" ]]; then
-      sudo_prefix=""
-      sudo_display=""
-    fi
    if [[ "$dry_run" -eq 1 ]]; then
      echo "[dry-run] would build on ${node}: nix build --no-use-registries --no-accept-flake-config${nix_opts_display} \\"
      echo "[dry-run]   .#nixosConfigurations.${flake_target}.config.system.build.diskoImagesScript"
@@ -728,7 +730,7 @@ REMOTE_SCRIPT
        "$remote_repo_dir" "$flake_target" "$remote_dir" "$remote_filename" "$NIX_EXTRA_OPTS" "$sudo_prefix"
      ssh "$ssh_target" "$remote_cmd" <<'REMOTE_SCRIPT'
 set -euo pipefail
-repo_dir="$1"; target="$2"; dest_dir="$3"; dest_name="$4"; nix_extra_opts_str="$5"; sudo_prefix="$6"
+repo_dir="$1"; target="$2"; dest_dir="$3"; dest_name="$4"; nix_extra_opts_str="$5"; sudo_pfx="$6"
 declare -a NIX_OPTS=()
 [[ -n "$nix_extra_opts_str" ]] && eval "NIX_OPTS=(${nix_extra_opts_str})"
 cd "$repo_dir"
@@ -737,7 +739,7 @@ ensure_nix_profile
 nix build --no-use-registries --no-accept-flake-config "${NIX_OPTS[@]}" \
  ".#nixosConfigurations.${target}.config.system.build.diskoImagesScript" \
  --out-link "result-${target}"
-$sudo_prefix "./result-${target}" \
+$sudo_pfx "./result-${target}" \
  --pre-format-files "host-keys/${target}_ssh_host_ed25519_key" /etc/ssh/ssh_host_ed25519_key \
  --pre-format-files "host-keys/${target}_ssh_host_ed25519_key.pub" /etc/ssh/ssh_host_ed25519_key.pub \
  --build-memory 2048
@@ -746,8 +748,8 @@ if [[ -z "$built" ]]; then
  echo "ERROR: no .raw image found in ${repo_dir} after build." >&2
  exit 1
 fi
-mkdir -p "$dest_dir"
-mv "$built" "${dest_dir}/${dest_name}"
+$sudo_pfx mkdir -p "$dest_dir"
+$sudo_pfx mv "$built" "${dest_dir}/${dest_name}"
 echo "Built and staged: ${dest_dir}/${dest_name}"
 REMOTE_SCRIPT
      local_image="$remote_path"
@@ -812,9 +814,9 @@ if [[ "$type" == "lxc" ]]; then
  # hands the whole string to `ssh` as a single command for the *remote*
  # shell to parse -- unquoted, that `;` would be read as a remote
  # command separator and silently truncate this into two commands.
-  create_cmd="pct create ${vmid} ${iso_storage}:vztmpl/${remote_filename} --unprivileged ${unprivileged_flag} --features '${PROXMOX_DEFAULT_LXC_FEATURES}' --rootfs ${storage}:${local_disk_size} --hostname ${name} --cores ${cores} --memory ${memory} --swap ${local_swap} --net0 name=eth0,bridge=${bridge},ip=dhcp"
+  create_cmd="${sudo_prefix} pct create ${vmid} ${iso_storage}:vztmpl/${remote_filename} --unprivileged ${unprivileged_flag} --features '${PROXMOX_DEFAULT_LXC_FEATURES}' --rootfs ${storage}:${local_disk_size} --hostname ${name} --cores ${cores} --memory ${memory} --swap ${local_swap} --net0 name=eth0,bridge=${bridge},ip=dhcp"
  remote "$create_cmd"
-  remote "pct start ${vmid}"
+  remote "${sudo_prefix} pct start ${vmid}"
 else
  echo "==> Creating VM ${vmid} (${name})..."
  # pre-enrolled-keys=0 disables OVMF's Secure Boot key pre-enrollment --
@@ -825,29 +827,29 @@ else
  # without this flag Proxmox never creates the channel it listens on, so
  # `qm guest exec`/`qm agent` and the UI's IP-address display silently
  # never work for any VM this script creates.
-  remote "qm create ${vmid} --name ${name} --memory ${memory} --cores ${cores} \
+  remote "${sudo_prefix} qm create ${vmid} --name ${name} --memory ${memory} --cores ${cores} \
 --net0 virtio,bridge=${bridge} --bios ovmf --machine q35 --scsihw virtio-scsi-pci \
 --efidisk0 ${storage}:1,efitype=4m,pre-enrolled-keys=0 --agent enabled=1"

  if [[ "$dry_run" -eq 1 ]]; then
-    echo "[dry-run] ssh ${ssh_target} -- qm importdisk ${vmid} ${remote_path} ${storage}"
+    echo "[dry-run] ssh ${ssh_target} -- ${sudo_display}qm importdisk ${vmid} ${remote_path} ${storage}"
    echo "[dry-run] (would parse the resulting disk identifier from that output)"
-    echo "[dry-run] ssh ${ssh_target} -- qm set ${vmid} --scsi0 ${storage}:<parsed-disk-id>"
+    echo "[dry-run] ssh ${ssh_target} -- ${sudo_display}qm set ${vmid} --scsi0 ${storage}:<parsed-disk-id>"
  else
-    importdisk_output="$(ssh "$ssh_target" "qm importdisk ${vmid} ${remote_path} ${storage}")"
+    importdisk_output="$(ssh "$ssh_target" "${sudo_prefix} qm importdisk ${vmid} ${remote_path} ${storage}")"
    echo "$importdisk_output"
    disk_id="$(echo "$importdisk_output" | grep -oP "(?<=Successfully imported disk as ')[^']+" | sed 's/^unused[0-9]*://')"
    if [[ -z "$disk_id" ]]; then
      echo "ERROR: couldn't parse the imported disk identifier from qm importdisk's output above." >&2
      echo "The VM shell (${vmid}) and imported disk both exist -- finish attaching it by hand:" >&2
-      echo "  ssh ${ssh_target} -- qm set ${vmid} --scsi0 ${storage}:<disk-id-from-output-above>" >&2
-      echo "  ssh ${ssh_target} -- qm set ${vmid} --boot order=scsi0" >&2
+      echo "  ssh ${ssh_target} -- ${sudo_display}qm set ${vmid} --scsi0 ${storage}:<disk-id-from-output-above>" >&2
+      echo "  ssh ${ssh_target} -- ${sudo_display}qm set ${vmid} --boot order=scsi0" >&2
      exit 1
    fi
-    remote "qm set ${vmid} --scsi0 ${disk_id}"
+    remote "${sudo_prefix} qm set ${vmid} --scsi0 ${disk_id}"
  fi
-  remote "qm set ${vmid} --boot order=scsi0"
-  remote "qm start ${vmid}"
+  remote "${sudo_prefix} qm set ${vmid} --boot order=scsi0"
+  remote "${sudo_prefix} qm start ${vmid}"
 fi

 echo
@@ -45,12 +45,20 @@
  # the installer image's nixos/root users.
  adminSshKey = "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQCq/Q5LvIXlZwO2kdeAN5nLGZ59nZB7JHYMEszHxmNtGMzv1lM31jiPNsr0z2EKVZhE7OOfa2IF9rhWYD7JUA9G0yzdZ4WTXFNGVVOJoOVH6vAF3XCxoVilOEwTc7h2Wiy+rzd0B28/3spffzQQWJhY6GRQVa8j+6xAGF60Fcvl1vLosYT9Bn2ZbK4TCWOwAn2jqXIieGpZdn/UNZbGOeKRiCvhktDfMAzuQzN/9jMu/oF4pkPn2X1UrsQdNlvp0Ci8md612MozIpncQJyAF1ADhunr3sMx0isUXiqD29R5DS4TftpekqLNLak+zcxFa8N7DcRNp3DcKfJvyTkwQrR4r+b7lFLYOLHLagSso9CzeW/paAS2q9I5SBm/2DtE1diLLg2jZikYcstsu/G5RgvbzbKqjiaMwTdXC3AMvDxQrs7U5pDRZFzoofG3cpODbTm+uy3m0kP70z0M1K45UbDG0p+itnTu9x40JbQEgefbx38AItNvAIx1A8HO4I1VX28= wayne@stream";

-  # Prestaged wifi credentials for the gui host's NetworkManager profile
-  # (modules/networking/wifi.nix). Leave blank until the bare-metal
-  # hardware profile is wired up — an empty ssid disables the profile
-  # rather than creating a broken empty one.
+  # Prestaged wifi SSID for the gui host's NetworkManager profile
+  # (modules/networking/wifi.nix). The password is not here -- it's
+  # sops-encrypted in secrets/gui.yaml (wifi-password) instead, since this
+  # file isn't a secret store.
  wifiSsid = "nbn-fttp-net-5G";

+  # Bare-metal gui host's two disks for a ZFS RAID0 (striped) root pool
+  # (modules/disko/baremetal.nix). Only used transiently at disko-format
+  # time (partitioning); the resulting fileSystems/zpool import reference
+  # by-partlabel/by-id paths afterward regardless, same as
+  # modules/disko/proxmox.nix's own plain "/dev/sda".
+  guiRootDisk1 = "/dev/sda";
+  guiRootDisk2 = "/dev/sdb";
+
  # System
  timeZone = "Australia/Brisbane";