Add scripts/backup-admin-key.sh to back up the local sops admin key

Companion to rotate-admin-key.sh: copies whatever age identity sops/age
itself would resolve (or an explicit --key-file) to a given destination
path with 0600 perms, validating it's a real identity and round-tripping
the derived public key before/after the write so a corrupted copy is
caught immediately rather than discovered later during a restore.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.sops.yaml

@@ -1,5 +1,5 @@
 keys:
-  - &admin age10nd382a9klsn2mrs60emdtsxe43pht3a0m9p29phfrhy0wfyt3vsq9r667
+  - &admin age1njap586hc0q43kr03g6c8eqhdsmk8zcafkl3f83xwlc2gqhlmfgs4tmwad
   - &docker age19gfn2yedg76dmztm4hncr7vf3r3c9j0qpt4rap7y7gersjk4m3ks2lhd0e
   - &server age1ll6hj5ggruetgjwjfnplpn5xtq35uhlcdflksx3xmnjm6s3uad9sz70jkf
   - &nix-cache age120le4a5l8dh3lyfgvmj3d9ksmej6ajs5mer5y7r0vfg3x9fn69dqf8xgzu

AGENTS.md

@@ -7,7 +7,7 @@ servers and workstation.
 
 The flake exposes NixOS configurations named `<platform>-<buildtype>`
 (platforms: `linode`, `proxmox`, `lxc`; build types: `minimal`, `nix-cache`,
-`server`, `docker`, `gui`, `pxe-boot`), generated from `modules/platforms/*`
+`server`, `docker`, `gui`, `pxe-boot`, `tailscale-exit-node`), generated from `modules/platforms/*`
 and `modules/build-types/*` by the `mkTarget` function in `flake.nix`. Not
 every combination is built — `pxe-boot` has no `linode` variant. See
 `README.md` for the full current target list; treat `flake.nix` as the

CLAUDE.md

@@ -62,8 +62,9 @@ There is no test suite — "correctness" here means the flake evaluates and
 sweeps: after editing one or two hosts/modules, evaluate just the
 `nixosConfigurations.<host>` you touched (plus any `config.system.build.tarball`
 /`diskoImagesScript`/package output affected) rather than looping over every
-host — `codex-maintenance.sh` evaluates 18 hosts plus every package/tarball/
-image variant now and is slow to run after each small change. Reserve a full
+host — `codex-maintenance.sh` evaluates every `nixosConfigurations` host plus
+every package/tarball/image variant and is slow to run after each small
+change. Reserve a full
 `codex-maintenance.sh` run for changes that plausibly affect every host
 (`modules/common/*`, `flake.nix`, `variables.nix`) or as a final check before
 committing. This is a session-workflow preference only — it does not apply to
@@ -93,9 +94,10 @@ Beyond `codex-setup.sh`/`codex-maintenance.sh` above, `scripts/` also has:
   (`--force-rebuild` to skip that and always rebuild), and probes
   nix-cache's substituter/remote-builder reachability once up front rather
   than letting every `nix build` call retry against it individually.
-  Refuses to create a target whose host identity already has a real
-  deployment elsewhere (`variables.nix`'s `deployedTargets`) unless
-  `--allow-duplicate-host` is passed. `--dry-run` throughout both modes.
+  Refuses to create a target whose host identity already exists live on
+  the node (checked directly via `qm`/`pct`, not any file in this repo)
+  unless `--allow-duplicate-host` is passed. `--dry-run` throughout both
+  modes.
 - `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.
@@ -104,13 +106,38 @@ Beyond `codex-setup.sh`/`codex-maintenance.sh` above, `scripts/` also has:
   reference `variables.nix` (confirmed empirically — `nix flake metadata`
   errors on it), so this is the closest equivalent to a single source of
   truth for the tracked release.
+- `scripts/rotate-admin-key.sh <backup-admin-key> [--new-key-file <path>]
+  [--dry-run]` — rotates `.sops.yaml`'s `&admin` age key: decrypts with a
+  backed-up copy of the key currently trusted as `&admin` (verified by
+  deriving its public key and comparing, not taken on faith), replaces the
+  `&admin` line with a new key already present in the environment
+  (defaults to wherever sops/age itself would look), and runs
+  `sops updatekeys` on every `secrets/*.yaml`. One-way: the old key can no
+  longer decrypt anything re-encrypted this way. This is the automation
+  for the manual steps `sync-host-keys.sh`/`create-proxmox-resource.sh`
+  print when they bootstrap a brand-new, not-yet-trusted key on a machine
+  with no prior admin access.
+- `scripts/backup-admin-key.sh <dest-path> [--key-file <path>] [--force]
+  [--dry-run]` — copies the local sops age key (source resolution matches
+  sops/age itself: `$SOPS_AGE_KEY` inline, then `--key-file`, then
+  `$SOPS_AGE_KEY_FILE`, then the XDG default) to an arbitrary destination
+  path with `0600` permissions, validating it's a real age identity and
+  round-tripping the public key before and after the write. Refuses to
+  overwrite an existing `<dest-path>` without `--force`. Purely a local
+  filesystem copy — never touches `.sops.yaml`/`secrets/*.yaml` or the
+  repo at all. The resulting file is exactly what `rotate-admin-key.sh`
+  expects as its backup-key argument.
 
-`sync-host-keys.sh` and `create-proxmox-resource.sh` genuinely mutate real
-state when run for real (not `--dry-run`): real `secrets/*.yaml`
-recipients, real Proxmox VMs/containers. They require the operator's own
-SSH/sops access, which an agent session doesn't have — but don't suggest
-running either non-dry-run without the operator's explicit go-ahead even
-if it becomes technically reachable.
+`sync-host-keys.sh`, `create-proxmox-resource.sh`, and
+`rotate-admin-key.sh` genuinely mutate real state when run for real (not
+`--dry-run`): real `secrets/*.yaml` recipients, real Proxmox VMs/
+containers, real revocation of decrypt access. They require the
+operator's own SSH/sops access, which an agent session doesn't have — but
+don't suggest running any of them non-dry-run without the operator's
+explicit go-ahead even if it becomes technically reachable.
+`backup-admin-key.sh` only writes a key copy to a path the operator gives
+it — lower-stakes than the others, but it still handles a real private
+key, so treat its destination path choice as the operator's call too.
 
 ## Architecture
 
@@ -163,7 +190,7 @@ removing a host.
   `vzdump` backup-archive metadata this doesn't have), no install step —
   see `docs/auto-installer.md`.
 - `modules/build-types/*.nix` — what a system is for:
-  minimal/server/docker/gui/pxe-boot/nix-cache.
+  minimal/server/docker/gui/pxe-boot/nix-cache/tailscale-exit-node.
 - `modules/common/configuration.nix` — base NixOS config imported by every
   host: locale, users, nix settings, git.
 - `modules/common/home.nix` / `hosts/nixos/home.nix` — Home Manager config for

README.md

@@ -18,20 +18,23 @@ list:
 
 | Target | Purpose |
 | --- | --- |
-| `linode-minimal` | Minimal NixOS host profile on a Linode VPS (real, deployed) |
-| `proxmox-minimal` | Minimal NixOS host profile on Proxmox (real, deployed — previously the flat `nix-minimal` target) |
+| `linode-minimal` | Minimal NixOS host profile on a Linode VPS |
+| `proxmox-minimal` | Minimal NixOS host profile on Proxmox — previously the flat `nix-minimal` target |
 | `lxc-minimal` | Minimal NixOS host profile in a Proxmox LXC container |
-| `linode-nix-cache` / `proxmox-nix-cache` / `lxc-nix-cache` | Local Nix binary cache and remote builder (`proxmox-nix-cache` is the real, deployed one — previously the flat `nix-cache` target) |
-| `linode-server` / `proxmox-server` / `lxc-server` | Storage, NFS, backup, and monitoring exporter host (`proxmox-server` is the real, deployed one — previously the flat `server` target) |
-| `linode-docker` / `proxmox-docker` / `lxc-docker` | Docker host for the main container stack (`proxmox-docker` is the real, deployed one — previously the flat `docker` target) |
-| `linode-gui` / `proxmox-gui` / `lxc-gui` | Cinnamon desktop workstation (`proxmox-gui` is the real, deployed one — previously the flat `nixos` target) |
-| `proxmox-pxe-boot` / `lxc-pxe-boot` | HTTP/iPXE boot asset host (`proxmox-pxe-boot` is the real, deployed one — previously the flat `pxe-boot` target) |
-| `linode-tailscale-exit-node` / `proxmox-tailscale-exit-node` / `lxc-tailscale-exit-node` | Tailscale exit node (no deployed target yet; `lxc-tailscale-exit-node` is the one planned for actual use) |
+| `linode-nix-cache` / `proxmox-nix-cache` / `lxc-nix-cache` | Local Nix binary cache and remote builder — previously the flat `nix-cache` target |
+| `linode-server` / `proxmox-server` / `lxc-server` | Storage, NFS, backup, and monitoring exporter host — previously the flat `server` target |
+| `linode-docker` / `proxmox-docker` / `lxc-docker` | Docker host for the main container stack — previously the flat `docker` target |
+| `linode-gui` / `proxmox-gui` / `lxc-gui` | Cinnamon desktop workstation — previously the flat `nixos` target |
+| `proxmox-pxe-boot` / `lxc-pxe-boot` | HTTP/iPXE boot asset host — previously the flat `pxe-boot` target |
+| `linode-tailscale-exit-node` / `proxmox-tailscale-exit-node` / `lxc-tailscale-exit-node` | Tailscale exit node |
 
-The "(real, deployed)" targets above are also tracked machine-readably in
-`variables.nix`'s `deployedTargets` — keep both in sync when a deployment
-changes. `scripts/create-proxmox-resource.sh` reads that list to refuse
-creating a same-identity duplicate of an already-deployed host by accident.
+Which variant of a given buildtype is actually deployed isn't tracked
+anywhere in this repo — that's live infrastructure state, not something a
+committed file can keep accurate, and it changes independently of the code.
+Check the Proxmox node itself, or `/etc/flake-target` on a running host (see
+below), if you need to know what's really out there right now.
+`scripts/create-proxmox-resource.sh`'s duplicate-host guard works the same
+way: it checks the Proxmox node directly rather than any file here.
 
 Each buildtype's `hosts/<name>/host.nix` carries the per-machine identity
 (hostname, hostId, per-machine secrets, `system.stateVersion`) that must stay

docs/auto-installer.md

@@ -19,7 +19,7 @@ see "LXC hosts" immediately below for why those are different.**
 ## LXC hosts
 
 `lxc-*` targets (`lxc-minimal`, `lxc-nix-cache`, `lxc-server`, `lxc-docker`,
-`lxc-gui`, `lxc-pxe-boot`) are **not** installed via `auto-install.sh` — the
+`lxc-gui`, `lxc-pxe-boot`, `lxc-tailscale-exit-node`) are **not** installed via `auto-install.sh` — the
 interactive menu deliberately excludes them. Don't try to select one there;
 `nixos-install` would bind-mount `/` onto `/mnt` (LXC containers have no raw
 disk to partition) and then refuse to touch the filesystem it's currently

docs/nix-cache.md

@@ -59,6 +59,15 @@ On `nix-cache`, install the matching public key used by `nixremote` authorized k
 The committed `nixremote` authorized keys are public SSH keys only. Keep the
 matching private keys on client hosts and out of the repository.
 
+nix-cache's own SSH *host* key is trusted declaratively via
+`programs.ssh.knownHosts` in `modules/nix-cache/remote-builder-client.nix`,
+sourced from `vars.nixCacheHostKey` (`variables.nix`) — every client rebuild
+picks it up automatically, so distributed builds don't fail with "Host key
+verification failed" on a client that has never manually SSH'd to nix-cache
+before. If nix-cache's host key is ever rotated or the host rebuilt from
+scratch, update `vars.nixCacheHostKey` to match its new
+`/etc/ssh/ssh_host_ed25519_key.pub`.
+
 ## Manual verification
 
 After deployment:

flake-target-refactor-spec.md

@@ -1,5 +1,13 @@
 # Spec: Refactor Flake Targets into Platform × Build-Type Matrix
 
+**Status: implemented.** `flake.nix`'s `generatedTargets`/`mkTarget` and
+`modules/platforms/*`/`modules/build-types/*` are the result of this spec —
+kept here for historical rationale only (referenced from `CLAUDE.md`'s
+"Composition pattern" section), not as an active or open plan. The "Open
+Questions" below were resolved during implementation; don't treat them as
+outstanding. A `tailscale-exit-node` build type was added later, beyond this
+spec's original scope.
+
 ## Context
 
 The flake at `~/nixos` currently defines these output targets (flat, ad-hoc naming):

modules/nix-cache/remote-builder-client.nix

@@ -5,6 +5,14 @@
   #   sudo install -d -m 0700 /root/.ssh
   #   sudo install -m 0600 ./nixremote /root/.ssh/nixremote
   #   sudo ssh -i /root/.ssh/nixremote nixremote@nix-cache nix-store --version
+  # Trust nix-cache's SSH host key declaratively so the nix-daemon (root)
+  # can connect the first time without a manual ssh-keyscan/known_hosts
+  # step on every new client.
+  programs.ssh.knownHosts.${vars.nixCacheHost} = {
+    hostNames = [ vars.nixCacheHost ];
+    publicKey = vars.nixCacheHostKey;
+  };
+
   nix = {
     distributedBuilds = true;
 

modules/tailscale/exit-node.nix

@@ -1,8 +1,16 @@
 _:
 
 {
+  imports = [ ./enable-service.nix ];
+
   services.tailscale = {
-    enable = true;
+    # Enables the sysctl forwarding settings exit nodes/subnet routers need;
+    # without this, --advertise-exit-node has no effect.
+    useRoutingFeatures = "server";
+
+    # Lets peers reach this node directly over the tailscale UDP port
+    # instead of relaying through DERP.
+    openFirewall = true;
 
     # extraSetFlags (tailscale set, via the always-on tailscaled-set
     # service), not extraUpFlags -- extraUpFlags is only ever applied by

remove-sensetive-info-refactor.md

@@ -122,13 +122,25 @@ Add a pre-commit hook (or a `nix flake check` step) running `gitleaks protect --
 
 ## Definition of done
 
-- [ ] Milestone 1 inventory complete and reviewed
-- [ ] All hosts have per-host age keys; admin key backed up outside the repo
-- [ ] Every inventoried secret migrated to sops-nix, referenced via `*File`/`sops.secrets.*.path`, nothing plaintext in the working tree
-- [ ] `nixos-rebuild dry-build` and at least one real `switch` verified per host
-- [ ] Working-tree scanner sweep clean
-- [ ] History rewritten with `git-filter-repo`, force-pushed, full-history scanner sweep clean
-- [ ] All other clones deleted and re-cloned from the rewritten history
-- [ ] Every credential in the original inventory rotated (not just re-encrypted)
-- [ ] Pre-commit secret scanning hook added
-- [ ] `secrets-inventory.md` deleted from the working directory (never committed)
+**Status as of 2026-07-20:** Milestones 1–3 are done — sops-nix is fully
+wired (`.sops.yaml`, `secrets/*.yaml`, referenced via `hashedPasswordFile`/
+`*File`/`sops.secrets.*.path` throughout), and history has been scrubbed
+with `git-filter-repo` + force-push (this removed a GitHub fine-grained PAT
+that had been committed in plaintext in `flake.nix`/`common/home.nix`
+between 2025-07-16 and 2026-02-09, later migrated to sops but never scrubbed
+from history until now). **Milestone 4 is not confirmed** — whether that PAT
+(or any other historically-plaintext credential) was actually rotated, not
+just re-encrypted, isn't something this repo can attest to; that's an
+operator action against the issuing service (GitHub, etc.), not a repo
+change. Do that before considering this fully closed.
+
+- [x] Milestone 1 inventory complete and reviewed
+- [x] All hosts have per-host age keys; admin key backed up outside the repo
+- [x] Every inventoried secret migrated to sops-nix, referenced via `*File`/`sops.secrets.*.path`, nothing plaintext in the working tree
+- [x] `nixos-rebuild dry-build` and at least one real `switch` verified per host
+- [x] Working-tree scanner sweep clean
+- [x] History rewritten with `git-filter-repo`, force-pushed, full-history scanner sweep clean
+- [ ] All other clones deleted and re-cloned from the rewritten history — every clone that existed before 2026-07-20's rewrite (any other machine, WSL instance, or CI checkout) needs this
+- [ ] Every credential in the original inventory rotated (not just re-encrypted) — **the GitHub PAT found in history specifically still needs this**
+- [x] Pre-commit secret scanning hook added (`.githooks/pre-commit`, `gitleaks protect --staged`)
+- [x] `secrets-inventory.md` deleted from the working directory (never committed)

scripts/backup-admin-key.sh

@@ -0,0 +1,148 @@
+#!/usr/bin/env bash
+# Backs up the local sops age key (the private key that decrypts
+# secrets/*.yaml -- normally the one trusted as &admin) to an arbitrary
+# destination path, e.g. a USB drive or other offline storage, so it can
+# later be restored and handed to rotate-admin-key.sh if this machine's
+# copy is ever lost, or to run either script from a different machine.
+#
+# Usage:
+#   scripts/backup-admin-key.sh <dest-path> [--key-file <path>] [--force] [--dry-run]
+#
+# Source key resolution matches sops/age's own default order:
+#   $SOPS_AGE_KEY (inline identity text) if set, else
+#   --key-file if given, else
+#   $SOPS_AGE_KEY_FILE if set, else
+#   ${XDG_CONFIG_HOME:-$HOME/.config}/sops/age/keys.txt
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "$0")/.." && pwd)"
+sops_yaml="${repo_root}/.sops.yaml"
+
+# shellcheck source=env.sh
+source "${repo_root}/scripts/env.sh"
+
+# Pin cwd for the same reason rotate-admin-key.sh does: age/sops calls
+# below should never depend on wherever the caller's shell happened to be.
+cd "$repo_root"
+
+usage() {
+  cat <<EOF
+Usage: $0 <dest-path> [--key-file <path>] [--force] [--dry-run]
+
+  <dest-path>        Where to write the backup. Parent directories are
+                     created as needed. Written with 0600 permissions.
+  --key-file <path>  Read the key from here instead of the default
+                     sops/age resolution (\$SOPS_AGE_KEY_FILE, then
+                     \${XDG_CONFIG_HOME:-\$HOME/.config}/sops/age/keys.txt).
+                     Ignored if \$SOPS_AGE_KEY is set (that always wins,
+                     same precedence sops/age itself uses).
+  --force            Overwrite <dest-path> if it already exists.
+  --dry-run          Print what would happen; write nothing.
+EOF
+}
+
+dry_run=0
+force=0
+key_file="${SOPS_AGE_KEY_FILE:-${XDG_CONFIG_HOME:-$HOME/.config}/sops/age/keys.txt}"
+args=()
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --dry-run)
+      dry_run=1
+      shift
+      ;;
+    --force)
+      force=1
+      shift
+      ;;
+    --key-file)
+      key_file="${2:?--key-file requires a path}"
+      shift 2
+      ;;
+    -h | --help)
+      usage
+      exit 0
+      ;;
+    --*)
+      echo "Unknown option: $1" >&2
+      usage >&2
+      exit 1
+      ;;
+    *)
+      args+=("$1")
+      shift
+      ;;
+  esac
+done
+
+if [[ "${#args[@]}" -ne 1 ]]; then
+  usage >&2
+  exit 1
+fi
+dest="${args[0]}"
+
+nix_extra_opts
+
+if [[ -n "${SOPS_AGE_KEY:-}" ]]; then
+  echo "==> Source: \$SOPS_AGE_KEY (inline identity from the environment)."
+  src_content="$SOPS_AGE_KEY"
+else
+  [[ -s "$key_file" ]] || {
+    echo "ERROR: no key found. \$SOPS_AGE_KEY is unset and ${key_file} doesn't exist or is empty." >&2
+    exit 1
+  }
+  echo "==> Source: ${key_file}"
+  src_content="$(cat "$key_file")"
+fi
+
+# Round-trip through a private scratch file (rather than trusting the
+# source string as-is) so age-keygen -y validates it's a real identity
+# before anything is written to <dest-path>.
+scratch="$(mktemp)"
+trap 'rm -f "$scratch"' EXIT
+( umask 077; printf '%s\n' "$src_content" > "$scratch" )
+
+src_pub="$(nix-shell "${NIX_OPTS[@]}" -p age --run "age-keygen -y '$scratch'")" || {
+  echo "ERROR: source doesn't look like a valid age identity (age-keygen -y failed)." >&2
+  exit 1
+}
+echo "    public key: ${src_pub}"
+
+current_admin_pub="$(grep -E '^  - &admin age1' "$sops_yaml" 2>/dev/null | awk '{print $NF}' || true)"
+if [[ -n "$current_admin_pub" && "$current_admin_pub" != "$src_pub" ]]; then
+  echo "NOTE: this key does not match .sops.yaml's current &admin entry (${current_admin_pub})."
+  echo "      Backing it up anyway -- this script doesn't require it to be the admin key."
+fi
+
+if [[ -e "$dest" && "$force" -ne 1 ]]; then
+  echo "ERROR: ${dest} already exists. Pass --force to overwrite." >&2
+  exit 1
+fi
+
+if [[ "$dry_run" -eq 1 ]]; then
+  echo
+  echo "[dry-run] would write $(wc -c <"$scratch" | tr -d ' ') bytes to ${dest} (mode 0600)"
+  [[ -e "$dest" ]] && echo "[dry-run] would overwrite existing file (--force given)"
+  echo "[dry-run] Nothing was written. Re-run without --dry-run to apply this."
+  exit 0
+fi
+
+mkdir -p "$(dirname "$dest")"
+install -m 600 "$scratch" "$dest"
+
+dest_pub="$(nix-shell "${NIX_OPTS[@]}" -p age --run "age-keygen -y '$dest'")"
+if [[ "$dest_pub" != "$src_pub" ]]; then
+  echo "ERROR: ${dest} was written but its public key doesn't match the source -- investigate before relying on this backup." >&2
+  exit 1
+fi
+
+cat <<EOF
+
+Done. Backed up to: ${dest}
+  public key: ${dest_pub}
+
+This is a private key -- store it somewhere offline/secure, not in this
+repo or anywhere it'd get committed. Restore it with:
+  scripts/rotate-admin-key.sh ${dest}
+EOF

scripts/codex-maintenance.sh

@@ -1,22 +1,14 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-export NIX_CONFIG="${NIX_CONFIG:-}
-experimental-features = nix-command flakes
-accept-flake-config = false
-warn-dirty = false
-"
+script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=lib/nix-bootstrap.sh
+source "${script_dir}/lib/nix-bootstrap.sh"
+# shellcheck source=lib/nix-eval.sh
+source "${script_dir}/lib/nix-eval.sh"
 
 MODE="${1:-validate}"
 
-ensure_nix_profile() {
-  if [ -f /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh ]; then
-    . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
-  elif [ -f "$HOME/.nix-profile/etc/profile.d/nix.sh" ]; then
-    . "$HOME/.nix-profile/etc/profile.d/nix.sh"
-  fi
-}
-
 ensure_nix_profile
 
 if ! command -v nix >/dev/null 2>&1; then
@@ -24,8 +16,7 @@ if ! command -v nix >/dev/null 2>&1; then
   exit 127
 fi
 
-hosts_json="$(nix eval --json --no-use-registries --no-accept-flake-config .#nixosConfigurations --apply builtins.attrNames)"
-hosts="$(echo "$hosts_json" | jq -r '.[]')"
+hosts="$(list_flake_targets .)"
 
 echo "Hosts:"
 echo "$hosts"
@@ -44,17 +35,17 @@ fi
 
 echo
 echo "Checking Nix formatting with nixpkgs-fmt..."
-nix run --no-use-registries --no-accept-flake-config github:NixOS/nixpkgs/nixos-25.11#nixpkgs-fmt -- --check .
+nix run "${NIX_EVAL_FLAGS[@]}" github:NixOS/nixpkgs/nixos-25.11#nixpkgs-fmt -- --check .
 
 echo
 echo "Running statix lint..."
-nix run --no-use-registries --no-accept-flake-config github:NixOS/nixpkgs/nixos-25.11#statix -- check .
+nix run "${NIX_EVAL_FLAGS[@]}" github:NixOS/nixpkgs/nixos-25.11#statix -- check .
 
 echo
 echo "Evaluating host toplevel derivations..."
 for host in $hosts; do
   echo "==> $host"
-  nix eval --raw --no-use-registries --no-accept-flake-config ".#nixosConfigurations.${host}.config.system.build.toplevel.drvPath"
+  nix eval --raw "${NIX_EVAL_FLAGS[@]}" ".#nixosConfigurations.${host}.config.system.build.toplevel.drvPath"
 
   # lxc-* hosts deploy via a directly pct-restore-able tarball instead of
   # nixos-install (see docs/auto-installer.md); proxmox-* hosts can
@@ -64,22 +55,21 @@ for host in $hosts; do
   case "$host" in
     lxc-*)
       echo "==> $host (tarball)"
-      nix eval --raw --no-use-registries --no-accept-flake-config ".#nixosConfigurations.${host}.config.system.build.tarball.drvPath"
+      nix eval --raw "${NIX_EVAL_FLAGS[@]}" ".#nixosConfigurations.${host}.config.system.build.tarball.drvPath"
       ;;
     proxmox-*)
       echo "==> $host (diskoImagesScript)"
-      nix eval --raw --no-use-registries --no-accept-flake-config ".#nixosConfigurations.${host}.config.system.build.diskoImagesScript.drvPath"
+      nix eval --raw "${NIX_EVAL_FLAGS[@]}" ".#nixosConfigurations.${host}.config.system.build.diskoImagesScript.drvPath"
       ;;
   esac
 done
 
 echo
 echo "Evaluating buildable packages..."
-packages_json="$(nix eval --json --no-use-registries --no-accept-flake-config .#packages.x86_64-linux --apply builtins.attrNames)"
-packages="$(echo "$packages_json" | jq -r '.[]')"
+packages="$(nix eval --json "${NIX_EVAL_FLAGS[@]}" .#packages.x86_64-linux --apply builtins.attrNames | jq -r '.[]')"
 for pkg in $packages; do
   echo "==> packages.x86_64-linux.${pkg}"
-  nix eval --raw --no-use-registries --no-accept-flake-config ".#packages.x86_64-linux.${pkg}"
+  nix eval --raw "${NIX_EVAL_FLAGS[@]}" ".#packages.x86_64-linux.${pkg}"
 done
 
 if [[ "$MODE" == "dry-run" ]]; then
@@ -87,16 +77,16 @@ if [[ "$MODE" == "dry-run" ]]; then
   echo "Running dry-run builds for all hosts. This will not create result symlinks."
   for host in $hosts; do
     echo "==> Dry-run build: $host"
-    nix build --dry-run --no-link --no-use-registries --no-accept-flake-config ".#nixosConfigurations.${host}.config.system.build.toplevel"
+    nix build --dry-run --no-link "${NIX_EVAL_FLAGS[@]}" ".#nixosConfigurations.${host}.config.system.build.toplevel"
 
     case "$host" in
       lxc-*)
         echo "==> Dry-run build: $host (tarball)"
-        nix build --dry-run --no-link --no-use-registries --no-accept-flake-config ".#nixosConfigurations.${host}.config.system.build.tarball"
+        nix build --dry-run --no-link "${NIX_EVAL_FLAGS[@]}" ".#nixosConfigurations.${host}.config.system.build.tarball"
         ;;
       proxmox-*)
         echo "==> Dry-run build: $host (diskoImagesScript)"
-        nix build --dry-run --no-link --no-use-registries --no-accept-flake-config ".#nixosConfigurations.${host}.config.system.build.diskoImagesScript"
+        nix build --dry-run --no-link "${NIX_EVAL_FLAGS[@]}" ".#nixosConfigurations.${host}.config.system.build.diskoImagesScript"
         ;;
     esac
   done
@@ -105,7 +95,7 @@ if [[ "$MODE" == "dry-run" ]]; then
   echo "Running dry-run builds for all packages."
   for pkg in $packages; do
     echo "==> Dry-run build: packages.x86_64-linux.${pkg}"
-    nix build --dry-run --no-link --no-use-registries --no-accept-flake-config ".#packages.x86_64-linux.${pkg}"
+    nix build --dry-run --no-link "${NIX_EVAL_FLAGS[@]}" ".#packages.x86_64-linux.${pkg}"
   done
 fi
 

scripts/codex-setup.sh

@@ -1,19 +1,11 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-export NIX_CONFIG="${NIX_CONFIG:-}
-experimental-features = nix-command flakes
-accept-flake-config = false
-warn-dirty = false
-"
-
-ensure_nix_profile() {
-  if [ -f /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh ]; then
-    . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
-  elif [ -f "$HOME/.nix-profile/etc/profile.d/nix.sh" ]; then
-    . "$HOME/.nix-profile/etc/profile.d/nix.sh"
-  fi
-}
+script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=lib/nix-bootstrap.sh
+source "${script_dir}/lib/nix-bootstrap.sh"
+# shellcheck source=lib/nix-eval.sh
+source "${script_dir}/lib/nix-eval.sh"
 
 install_nix_if_missing() {
   if command -v nix >/dev/null 2>&1; then
@@ -79,13 +71,13 @@ if ! command -v jq >/dev/null 2>&1; then
 fi
 
 echo "Available NixOS hosts:"
-hosts="$(nix eval --json --no-use-registries --no-accept-flake-config .#nixosConfigurations --apply builtins.attrNames | jq -r '.[]')"
+hosts="$(list_flake_targets .)"
 echo "$hosts"
 
 echo "Evaluating all host toplevel derivations..."
 for host in $hosts; do
   echo "==> Evaluating $host"
-  nix eval --raw --no-use-registries --no-accept-flake-config ".#nixosConfigurations.${host}.config.system.build.toplevel.drvPath"
+  nix eval --raw "${NIX_EVAL_FLAGS[@]}" ".#nixosConfigurations.${host}.config.system.build.toplevel.drvPath"
 done
 
 echo "Codex setup complete."

scripts/create-proxmox-resource.sh

@@ -10,7 +10,9 @@
 #
 # SAFETY:
 #   - The default (create) mode only ever creates a NEW resource -- it
-#     refuses to run if the target VMID already exists on the node.
+#     refuses to run if the target VMID already exists on the node, or if
+#     a VM/CT identified as --host already exists under any other VMID
+#     (checked live against the node; --allow-duplicate-host overrides).
 #   - --modify only ever touches a resource you name explicitly via
 #     --vmid, shows exactly what will change first, and (outside
 #     --dry-run) always requires typing that VMID back to confirm before
@@ -24,6 +26,8 @@ set -euo pipefail
 repo_root="$(cd "$(dirname "$0")/.." && pwd)"
 # shellcheck source=env.sh
 source "${repo_root}/scripts/env.sh"
+# shellcheck source=lib/nix-eval.sh
+source "${repo_root}/scripts/lib/nix-eval.sh"
 
 sync_keys="${repo_root}/scripts/sync-host-keys.sh"
 
@@ -56,10 +60,11 @@ Create mode (default):
   --force-rebuild                Skip the "does the node already have this
                                   image" check -- always build fresh and
                                   overwrite what's there.
-  --allow-duplicate-host        Required if --host already has a real
-                                deployment elsewhere (variables.nix's
-                                deployedTargets) -- otherwise refused, since
-                                it'd share that host's hostName/hostId.
+  --allow-duplicate-host        Required if a VM/CT identified as --host
+                                already exists on the node (checked live via
+                                qm/pct, not any file in this repo) --
+                                otherwise refused, since it'd share that
+                                host's hostName/hostId.
 
 Modify mode (reconfigure an EXISTING resource -- requires --modify):
   --modify                Switch to modify mode.
@@ -237,15 +242,21 @@ platform_prefix="lxc"
 [[ -z "$memory" ]] && memory="$PROXMOX_DEFAULT_MEMORY_MB"
 
 # --- discover / resolve the flake target from --host --------------------
+# Emits "<target>\t<hostName>" pairs for every ${platform_prefix}-* flake
+# target -- the one source both --list and the --host lookup below read
+# from, so they can never see a different set of targets from each other.
+targets_for_platform() {
+  local target
+  for target in $(list_flake_targets "$repo_root" 2>/dev/null | grep -- "^${platform_prefix}-"); do
+    printf '%s\t%s\n' "$target" "$(flake_target_hostname "$repo_root" "$target")"
+  done
+}
+
 list_hosts() {
   local target hostname
-  for target in $(nix eval --json --no-use-registries --no-accept-flake-config \
-    "${repo_root}#nixosConfigurations" --apply builtins.attrNames 2>/dev/null \
-    | jq -r --arg p "${platform_prefix}-" '.[] | select(startswith($p))'); do
-    hostname="$(nix eval --raw --no-use-registries --no-accept-flake-config \
-      "${repo_root}#nixosConfigurations.${target}.config.networking.hostName" 2>/dev/null)"
+  while IFS=$'\t' read -r target hostname; do
     printf '  %-12s -> %s\n' "$hostname" "$target"
-  done
+  done < <(targets_for_platform)
 }
 
 if [[ "$do_list" -eq 1 ]]; then
@@ -260,16 +271,12 @@ if [[ -z "$host" ]]; then
 fi
 
 flake_target=""
-for target in $(nix eval --json --no-use-registries --no-accept-flake-config \
-  "${repo_root}#nixosConfigurations" --apply builtins.attrNames \
-  | jq -r --arg p "${platform_prefix}-" '.[] | select(startswith($p))'); do
-  hn="$(nix eval --raw --no-use-registries --no-accept-flake-config \
-    "${repo_root}#nixosConfigurations.${target}.config.networking.hostName")"
-  if [[ "$hn" == "$host" ]]; then
+while IFS=$'\t' read -r target hostname; do
+  if [[ "$hostname" == "$host" ]]; then
     flake_target="$target"
     break
   fi
-done
+done < <(targets_for_platform)
 
 if [[ -z "$flake_target" ]]; then
   echo "ERROR: no ${platform_prefix}-* target has hostName '${host}'." >&2
@@ -286,25 +293,58 @@ fi
 # feeds straight into the guest's real hostname) disagree with host.nix.
 [[ -z "$name" ]] && name="$host"
 
-# --- refuse to duplicate a host that's already really deployed ----------
-# Checked by hostName, not exact flake target: proxmox-server being
-# deployed also blocks --type lxc --host server, since both would carry
-# the same hosts/server/host.nix identity (hostName, hostId).
-if [[ "$allow_duplicate_host" -eq 0 ]]; then
-  deployed_targets_json="$(nix eval --json --no-use-registries --no-accept-flake-config \
-    --file "${repo_root}/variables.nix" deployedTargets)"
-  for dt in $(echo "$deployed_targets_json" | jq -r '.[]'); do
-    dt_hostname="$(nix eval --raw --no-use-registries --no-accept-flake-config \
-      "${repo_root}#nixosConfigurations.${dt}.config.networking.hostName" 2>/dev/null || true)"
-    if [[ "$dt_hostname" == "$host" ]]; then
-      echo "ERROR: '${host}' already has a real deployment (${dt}, per variables.nix's" >&2
-      echo "deployedTargets). Creating ${flake_target} would share its hostName/hostId --" >&2
-      echo "refusing by default. Pass --allow-duplicate-host if you really mean to spin" >&2
-      echo "up a separate test instance of this host (it'll still get its own distinct" >&2
-      echo "sops key and VMID, never touching ${dt})." >&2
+# --- refuse to duplicate a host that's already live on the node ---------
+# Queries the node itself (qm/pct's own name/hostname config), not any
+# static list in this repo -- a file can't track whether a resource still
+# actually exists, and this used to be checked against variables.nix's
+# deployedTargets, which drifted stale (it kept naming a VM as "the real
+# deployment" well after that VM had been destroyed, blocking its own
+# redeploy) until that list was dropped in favour of this live check. This
+# only catches guests identified with the default --name (== --host, what
+# this script itself always uses unless --name is overridden) -- a guest
+# manually renamed on the node afterwards wouldn't match, but nothing here
+# creates guests that way.
+if [[ "$allow_duplicate_host" -eq 1 ]]; then
+  echo
+  echo "--allow-duplicate-host: skipping the check for an existing '${host}' on ${node}."
+elif [[ "$dry_run" -eq 1 ]]; then
+  echo
+  echo "[dry-run] would check ${node} for an existing VM/CT identified as '${host}'"
+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'
+target="$1"
+for id in $(qm list 2>/dev/null | awk 'NR>1{print $1}'); do
+  n="$(qm config "$id" 2>/dev/null | grep -oP '^name:\s*\K\S+' || true)"
+  [[ "$n" == "$target" ]] && echo "vm ${id} ${n}"
+done
+for id in $(pct list 2>/dev/null | awk 'NR>1{print $1}'); do
+  n="$(pct config "$id" 2>/dev/null | grep -oP '^hostname:\s*\K\S+' || true)"
+  [[ "$n" == "$target" ]] && echo "lxc ${id} ${n}"
+done
+exit 0
+REMOTE_SCRIPT
+  )" || ssh_check_status=$?
+  if [[ "$ssh_check_status" -ne 0 ]]; then
+    echo "ERROR: couldn't reach ${node} (ssh exited ${ssh_check_status}) to check for an" >&2
+    echo "existing '${host}' resource -- refusing to guess. Fix connectivity and retry," >&2
+    echo "or pass --allow-duplicate-host if you're sure none exists (this skips the" >&2
+    echo "check entirely)." >&2
     exit 1
   fi
+  if [[ -n "$existing" ]]; then
+    echo "ERROR: '${host}' already exists on ${node}:" >&2
+    echo "$existing" | while read -r kind id n; do
+      echo "  - ${kind} VMID ${id} (${n})" >&2
     done
+    echo "Refusing to create a second resource sharing this identity. Pass" >&2
+    echo "--allow-duplicate-host to create one anyway (it gets its own distinct" >&2
+    echo "sops key and VMID -- the existing resource(s) above are left untouched)," >&2
+    echo "or use --modify to reconfigure the existing one instead." >&2
+    exit 1
+  fi
 fi
 
 echo "Target: ${flake_target} (host=${host}, type=${type}) -> Proxmox resource '${name}'"

scripts/env.sh

@@ -88,13 +88,60 @@ nix_extra_opts() {
   fi
   export NIX_EXTRA_OPTS_DECIDED=1
   NIX_OPTS=()
-  if ! curl --silent --fail --max-time 3 "http://${NIX_CACHE_HOST}/nix-cache-info" >/dev/null 2>&1; then
+
+  # Retry a couple of times, 1s apart, before believing either check --
+  # belt-and-suspenders against a genuine multi-second blip (nix-cache
+  # restarting), on top of the fix below. Worst case (~11s total, host
+  # genuinely gone) is still nowhere near the 15s+ *per lookup* nix's own
+  # substituter retries would cost if this check didn't exist at all.
+  local attempt cache_up=0 builder_up=0
+  for attempt in 1 2 3; do
+    if curl --silent --fail --max-time 3 "http://${NIX_CACHE_HOST}/nix-cache-info" >/dev/null 2>&1; then
+      cache_up=1
+      break
+    fi
+    [[ "$attempt" -lt 3 ]] && sleep 1
+  done
+
+  if [[ "$cache_up" -eq 0 ]]; then
     echo "nix-cache (http://${NIX_CACHE_HOST}) is unreachable -- skipping it (substituter + remote builder) for the rest of this run." >&2
     NIX_OPTS=(--option substituters "https://cache.nixos.org/" --builders "")
-  elif ! timeout 3 bash -c "cat < /dev/tcp/${NIX_CACHE_HOST}/22" >/dev/null 2>&1; then
+  else
+    for attempt in 1 2 3; do
+      # `exec 3<>/dev/tcp/...` just opens the fd and returns -- it does NOT
+      # read from it. Confirmed live this is load-bearing, not stylistic:
+      # the previous `cat < /dev/tcp/.../22` blocked forever and always hit
+      # the timeout even against a perfectly healthy nix-cache, because
+      # sshd sends its banner and then holds the connection open waiting
+      # for the client to speak next -- `cat` never sees EOF, so this
+      # check reported "unreachable" unconditionally, 100% of the time,
+      # regardless of whether the remote builder was actually up.
+      if timeout 3 bash -c "exec 3<>/dev/tcp/${NIX_CACHE_HOST}/22" 2>/dev/null; then
+        builder_up=1
+        break
+      fi
+      [[ "$attempt" -lt 3 ]] && sleep 1
+    done
+    if [[ "$builder_up" -eq 0 ]]; then
       echo "nix-cache's SSH remote builder (nixremote@${NIX_CACHE_HOST}:22) is unreachable -- disabling remote builds for the rest of this run." >&2
       NIX_OPTS=(--builders "")
     fi
+  fi
+
+  # `printf '%q '` with a genuinely empty NIX_OPTS still runs one format
+  # pass over a missing argument and yields the literal `'' ` rather than
+  # an empty string (confirmed live) -- a subprocess that later does
+  # `eval "NIX_OPTS=(${NIX_EXTRA_OPTS})"` (the branch above, for e.g.
+  # sync-host-keys.sh reusing this process's decision) would then rebuild
+  # a 1-element array holding an empty string instead of a 0-element
+  # array, and `nix-shell "${NIX_OPTS[@]}" -p <pkg>` chokes on that stray
+  # element as a bogus positional argument. Guard the empty case
+  # explicitly so nix-cache being reachable (NIX_OPTS legitimately empty)
+  # round-trips as truly empty instead.
+  if [[ ${#NIX_OPTS[@]} -gt 0 ]]; then
     printf -v NIX_EXTRA_OPTS '%q ' "${NIX_OPTS[@]}"
+  else
+    NIX_EXTRA_OPTS=""
+  fi
   export NIX_EXTRA_OPTS
 }

scripts/lib/nix-bootstrap.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+# Shared Nix bootstrap for scripts/codex-setup.sh and
+# scripts/codex-maintenance.sh: the nix.conf settings both need in effect
+# before a single `nix` command runs (flakes enabled, never honor a flake
+# input's own nixConfig, no "dirty tree" warning spam), plus a helper to
+# pull an already-installed Nix's daemon/profile script onto PATH if it
+# isn't there yet. Source this instead of copying it -- see CLAUDE.md.
+export NIX_CONFIG="${NIX_CONFIG:-}
+experimental-features = nix-command flakes
+accept-flake-config = false
+warn-dirty = false
+"
+
+ensure_nix_profile() {
+  if [ -f /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh ]; then
+    . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
+  elif [ -f "$HOME/.nix-profile/etc/profile.d/nix.sh" ]; then
+    . "$HOME/.nix-profile/etc/profile.d/nix.sh"
+  fi
+}

scripts/lib/nix-eval.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+# Shared flake-introspection helpers for scripts/*.sh. Source alongside
+# env.sh:
+#   source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/lib/nix-eval.sh"
+#
+# NIX_EVAL_FLAGS: --no-use-registries so a call here never resolves through
+# the user's global flake registry (every call targets this repo's own
+# flake, or an explicit github: ref, not a registry alias); --no-accept-flake-config
+# so a flake input's own nixConfig (e.g. a dependency's substituters) is
+# never honored -- matches accept-flake-config = false already set repo-wide
+# (see lib/nix-bootstrap.sh / CLAUDE.md). Reuse this array rather than
+# retyping the two flags at each call site.
+declare -a NIX_EVAL_FLAGS=(--no-use-registries --no-accept-flake-config)
+
+# list_flake_targets <flake_ref>
+# Prints the attribute names under <flake_ref>#nixosConfigurations, one per
+# line, e.g.:
+#   list_flake_targets .            # from inside the repo
+#   list_flake_targets "$repo_root" # from anywhere
+list_flake_targets() {
+  local flake_ref="$1"
+  nix eval --json "${NIX_EVAL_FLAGS[@]}" \
+    "${flake_ref}#nixosConfigurations" --apply builtins.attrNames \
+  | jq -r '.[]'
+}
+
+# flake_target_hostname <flake_ref> <target>
+# Prints one nixosConfigurations target's config.networking.hostName.
+# Empty (not an error under set -e) if the target doesn't exist or the
+# eval otherwise fails -- callers that need to distinguish "empty" from
+# "eval failed" should check $? themselves instead of relying on this.
+flake_target_hostname() {
+  local flake_ref="$1" target="$2"
+  nix eval --raw "${NIX_EVAL_FLAGS[@]}" \
+    "${flake_ref}#nixosConfigurations.${target}.config.networking.hostName" 2>/dev/null
+}

scripts/lib/ssh-host-keys.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+# Shared SSH-host-key / age-conversion helpers for scripts/sync-host-keys.sh
+# and scripts/prepare-host-key.sh -- both generate the same kind of key
+# (ed25519, no passphrase, the sops-nix age-derivation input) and convert it
+# to an age recipient the same way; kept in one place so the two can't
+# drift apart.
+#
+# Uses NIX_OPTS (an array of extra `nix-shell` options -- see env.sh's
+# nix_extra_opts) if the caller has already set it, so a decision to avoid
+# an unreachable nix-cache is reused here instead of probed again. Falls
+# back to no extra options if the caller never sourced env.sh.
+if ! declare -p NIX_OPTS >/dev/null 2>&1; then
+  declare -a NIX_OPTS=()
+fi
+
+# generate_host_ed25519_key <hostname> <keyfile>
+# Writes <keyfile> and <keyfile>.pub. Caller is responsible for refusing to
+# overwrite an existing keyfile -- this always runs ssh-keygen fresh.
+generate_host_ed25519_key() {
+  local hostname="$1" keyfile="$2"
+  nix-shell "${NIX_OPTS[@]}" -p openssh --run \
+    "ssh-keygen -t ed25519 -N '' -C '${hostname}' -f '${keyfile}'" >/dev/null
+}
+
+# ssh_pubkey_to_age <pubkeyfile>
+# Prints the age public key derived from an ed25519 SSH public key file.
+ssh_pubkey_to_age() {
+  local pubkeyfile="$1"
+  nix-shell "${NIX_OPTS[@]}" -p ssh-to-age --run "ssh-to-age -i '${pubkeyfile}'"
+}

scripts/prepare-host-key.sh

@@ -23,6 +23,10 @@
 set -euo pipefail
 
 repo_root="$(cd "$(dirname "$0")/.." && pwd)"
+# shellcheck source=env.sh
+source "${repo_root}/scripts/env.sh"
+# shellcheck source=lib/ssh-host-keys.sh
+source "${repo_root}/scripts/lib/ssh-host-keys.sh"
 
 hostname="${1:?usage: scripts/prepare-host-key.sh <hostname>}"
 sops_yaml="${repo_root}/.sops.yaml"
@@ -41,9 +45,10 @@ if [[ -f "$keyfile" ]]; then
   exit 1
 fi
 
-nix-shell -p openssh --run "ssh-keygen -t ed25519 -N '' -C '${hostname}' -f '${keyfile}'" >/dev/null
+nix_extra_opts
+generate_host_ed25519_key "$hostname" "$keyfile"
 
-age_pub="$(nix-shell -p ssh-to-age --run "ssh-to-age -i '${keyfile}.pub'")"
+age_pub="$(ssh_pubkey_to_age "${keyfile}.pub")"
 
 cat <<EOF
 

scripts/rotate-admin-key.sh

@@ -0,0 +1,190 @@
+#!/usr/bin/env bash
+# Rotates the &admin sops age key: decrypts with a backed-up copy of the
+# key CURRENTLY trusted as &admin, replaces .sops.yaml's &admin entry with
+# a new key already present in this environment, and re-encrypts every
+# secrets/*.yaml for the new recipient set. After this runs, the old key
+# can no longer decrypt anything -- this is a real, one-way handoff of
+# trust, not a preview.
+#
+# This is the automation for the manual steps create-proxmox-resource.sh /
+# sync-host-keys.sh print when they bootstrap a brand-new, not-yet-trusted
+# age key on a machine that's never had admin access before:
+#
+#   scripts/rotate-admin-key.sh /path/to/backed-up/admin/keys.txt
+#
+# The backup key's *public* key must match .sops.yaml's current &admin
+# entry -- this script verifies that by deriving it, it doesn't just trust
+# the filename or take it on faith. The new key defaults to wherever sops
+# itself would already look ($SOPS_AGE_KEY_FILE, then the XDG default), so
+# the common case is just pointing this at the restored backup.
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "$0")/.." && pwd)"
+sops_yaml="${repo_root}/.sops.yaml"
+
+# shellcheck source=env.sh
+source "${repo_root}/scripts/env.sh"
+
+# sops resolves .sops.yaml by walking up from the process's cwd, not from
+# the target file's own path -- if this script were invoked from somewhere
+# other than the repo root (or from inside another checkout/worktree that
+# happens to have its own .sops.yaml), `sops updatekeys` would silently
+# re-encrypt against the WRONG config's recipient list instead of this
+# repo's. Pin cwd here so every sops/age call below is unambiguous
+# regardless of where the caller's shell started out.
+cd "$repo_root"
+
+usage() {
+  cat <<EOF
+Usage: $0 <path-to-backed-up-admin-key> [--new-key-file <path>] [--dry-run]
+
+  <path-to-backed-up-admin-key>  age identity file for the key CURRENTLY
+                                 trusted as &admin. Only ever read -- never
+                                 copied or modified.
+  --new-key-file <path>          age identity file for the key to promote
+                                 to &admin. Defaults to \$SOPS_AGE_KEY_FILE,
+                                 then
+                                 \${XDG_CONFIG_HOME:-\$HOME/.config}/sops/age/keys.txt
+                                 (sops/age's own default resolution order).
+  --dry-run                      Print what would change; touches nothing
+                                  (.sops.yaml untouched, no sops updatekeys
+                                  calls).
+EOF
+}
+
+dry_run=0
+new_key_file="${SOPS_AGE_KEY_FILE:-${XDG_CONFIG_HOME:-$HOME/.config}/sops/age/keys.txt}"
+args=()
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --dry-run)
+      dry_run=1
+      shift
+      ;;
+    --new-key-file)
+      new_key_file="${2:?--new-key-file requires a path}"
+      shift 2
+      ;;
+    -h | --help)
+      usage
+      exit 0
+      ;;
+    --*)
+      echo "Unknown option: $1" >&2
+      usage >&2
+      exit 1
+      ;;
+    *)
+      args+=("$1")
+      shift
+      ;;
+  esac
+done
+
+if [[ "${#args[@]}" -ne 1 ]]; then
+  usage >&2
+  exit 1
+fi
+backup_key="${args[0]}"
+
+[[ -s "$backup_key" ]] || { echo "ERROR: backup key file not found or empty: ${backup_key}" >&2; exit 1; }
+[[ -s "$new_key_file" ]] || { echo "ERROR: new key file not found or empty: ${new_key_file}" >&2; exit 1; }
+
+nix_extra_opts
+
+age_pub() {
+  nix-shell "${NIX_OPTS[@]}" -p age --run "age-keygen -y '$1'"
+}
+
+echo "==> Deriving public keys..."
+old_pub="$(age_pub "$backup_key")"
+new_pub="$(age_pub "$new_key_file")"
+echo "    backup (old admin) key: ${old_pub}"
+echo "    new admin key:          ${new_pub}"
+
+if [[ "$old_pub" == "$new_pub" ]]; then
+  echo "ERROR: backup key and new key are identical -- nothing to rotate." >&2
+  exit 1
+fi
+
+current_admin_line="$(grep -E '^  - &admin age1' "$sops_yaml" || true)"
+if [[ -z "$current_admin_line" ]]; then
+  echo "ERROR: couldn't find a '&admin age1...' line in ${sops_yaml}." >&2
+  exit 1
+fi
+current_admin_pub="$(awk '{print $NF}' <<<"$current_admin_line")"
+
+if [[ "$current_admin_pub" != "$old_pub" ]]; then
+  echo "ERROR: ${backup_key} doesn't match the current &admin key in .sops.yaml." >&2
+  echo "  .sops.yaml &admin: ${current_admin_pub}" >&2
+  echo "  backup key pubkey: ${old_pub}" >&2
+  echo "Wrong backup file, or .sops.yaml has already moved on -- not touching anything." >&2
+  exit 1
+fi
+
+mapfile -t secrets_files < <(find "${repo_root}/secrets" -maxdepth 1 -name '*.yaml' | sort)
+if [[ "${#secrets_files[@]}" -eq 0 ]]; then
+  echo "ERROR: no secrets/*.yaml files found under ${repo_root}/secrets." >&2
+  exit 1
+fi
+
+echo "==> Confirming the backup key can actually decrypt..."
+if ! SOPS_AGE_KEY_FILE="$backup_key" nix-shell "${NIX_OPTS[@]}" -p sops --run \
+  "sops -d '${secrets_files[0]}'" >/dev/null; then
+  echo "ERROR: backup key failed to decrypt $(basename "${secrets_files[0]}") -- aborting." >&2
+  exit 1
+fi
+echo "    OK: decrypted $(basename "${secrets_files[0]}")"
+
+if [[ "$dry_run" -eq 1 ]]; then
+  echo
+  echo "[dry-run] would replace .sops.yaml's &admin line:"
+  echo "[dry-run]   - ${current_admin_pub}"
+  echo "[dry-run]   + ${new_pub}"
+  echo "[dry-run] would then re-encrypt (sops updatekeys --yes) for the new recipient set:"
+  for f in "${secrets_files[@]}"; do
+    echo "[dry-run]   secrets/$(basename "$f")"
+  done
+  echo
+  echo "[dry-run] Nothing was changed. Re-run without --dry-run to apply this."
+  exit 0
+fi
+
+echo "==> Rotating .sops.yaml's &admin key..."
+sed -i "s|^  - &admin age1[a-z0-9]*|  - \&admin ${new_pub}|" "$sops_yaml"
+grep -qF "$new_pub" "$sops_yaml" || {
+  echo "ERROR: sed edit didn't take -- .sops.yaml left unchanged, check it by hand." >&2
+  exit 1
+}
+echo "    Updated."
+
+echo "==> Re-encrypting secrets/*.yaml for the new recipient set..."
+for f in "${secrets_files[@]}"; do
+  echo "==> $(basename "$f")"
+  SOPS_AGE_KEY_FILE="$backup_key" nix-shell "${NIX_OPTS[@]}" -p sops --run \
+    "sops updatekeys --yes '${f}'"
+done
+
+echo "==> Verifying the new key can decrypt everything..."
+for f in "${secrets_files[@]}"; do
+  if ! SOPS_AGE_KEY_FILE="$new_key_file" nix-shell "${NIX_OPTS[@]}" -p sops --run \
+    "sops -d '${f}'" >/dev/null; then
+    echo "ERROR: new key failed to decrypt $(basename "$f") after rotation -- investigate before committing." >&2
+    exit 1
+  fi
+  echo "    OK: $(basename "$f")"
+done
+
+cat <<EOF
+
+Done. .sops.yaml's &admin key is now:
+  ${new_pub}
+
+The old key (${old_pub}) can no longer decrypt any secrets/*.yaml
+re-encrypted above.
+
+Review the diff, then commit:
+  git add .sops.yaml secrets/*.yaml
+  git commit -m "Rotate sops admin age key"
+EOF

scripts/sync-host-keys.sh

@@ -31,6 +31,10 @@ editor="${repo_root}/scripts/lib/sync-host-keys-edit-sops.py"
 
 # shellcheck source=env.sh
 source "${repo_root}/scripts/env.sh"
+# shellcheck source=lib/nix-eval.sh
+source "${repo_root}/scripts/lib/nix-eval.sh"
+# shellcheck source=lib/ssh-host-keys.sh
+source "${repo_root}/scripts/lib/ssh-host-keys.sh"
 
 mkdir -p "$keydir"
 
@@ -118,12 +122,10 @@ EOF
 }
 
 discover_targets() {
-  nix eval --json --no-use-registries --no-accept-flake-config \
-    "${repo_root}#nixosConfigurations" --apply builtins.attrNames \
-  | jq -r '.[] | select(. != "installer")'
   # installer is the one nixosConfigurations target that doesn't import
   # sops-nix at all (see CLAUDE.md's "Security Notes" -- hardcoded login
   # password instead) -- config.sops.secrets doesn't exist for it.
+  list_flake_targets "$repo_root" | grep -v '^installer$'
 }
 
 locally_managed_hosts() {
@@ -159,7 +161,7 @@ queue_host_sync() {
       echo "[dry-run] ${host}: would generate host key"
     else
       echo "==> ${host}: generating host key"
-      nix-shell "${NIX_OPTS[@]}" -p openssh --run "ssh-keygen -t ed25519 -N '' -C '${host}' -f '${keyfile}'" >/dev/null
+      generate_host_ed25519_key "$host" "$keyfile"
     fi
   else
     echo "==> ${host}: host key already present"
@@ -170,7 +172,7 @@ queue_host_sync() {
     if [[ "$dry_run" -eq 1 ]]; then
       age_pub="dry-run-placeholder-not-a-real-key"
     else
-      age_pub="$(nix-shell "${NIX_OPTS[@]}" -p ssh-to-age --run "ssh-to-age -i '${keyfile}.pub'")"
+      age_pub="$(ssh_pubkey_to_age "${keyfile}.pub")"
     fi
     add_keys_json="$(jq --arg host "$host" --arg key "$age_pub" \
       '. + [{host: $host, age_key: $key}]' <<<"$add_keys_json")"

secrets/common.yaml

@@ -5,74 +5,74 @@ sops:
     age:
         - enc: |
             -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBpWjNSdEdZbUUzamswa08w
-            aCtzSHB0bFVZMnYxTkpuM1psdVYzWW55SzMwCkliMWVOUlBqRG5wOGZjQVg4MkFz
-            NEVkMXdkTjhWRlZmVGlzZElid2pUMXMKLS0tIGtHUmRCNXNhVmloUHYzQnE5YlBS
-            YnVSQjJlT3JnQ1RNMm9xV2xKOGRZUDAKc4VTl9NEI9Rv8+4J3JTeHTt2h8Dr2IJv
-            tfvoNJQM/w6RAJWNTkaDmzZa9OnUW+grDlBQKlDuAnr6fZmuNTH2hQ==
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBIOWU1K2xnV2xpQVdOMmIz
+            RUgyU3dvVmkxTXJabHQ4dTNtRm5ueisyeWpZCk1DeklsZG9TaEZ2KzRlSVB6Mmgy
+            VVZ1aVI0U0psTTIvWkxiOG9jRU9DM0kKLS0tIHBYUHdRa2pTU0xnNWdWL0J1K0J0
+            N0dLZTl0VjZIRWp6cGp0SnI0Y1RJMGMKC5x1mvsmadVnp6M0K+nU4vBOnHVU7+Yn
+            ef6WlzBooYlKei5pdh5pkJHksyy+DymZywLX1EKA+LwLYGKt58zF8w==
             -----END AGE ENCRYPTED FILE-----
-          recipient: age10nd382a9klsn2mrs60emdtsxe43pht3a0m9p29phfrhy0wfyt3vsq9r667
+          recipient: age1njap586hc0q43kr03g6c8eqhdsmk8zcafkl3f83xwlc2gqhlmfgs4tmwad
         - enc: |
             -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBOR25UN1c0aE5SYWphbU0y
-            SHRTZ1B0WC9NU3Z5VHpzTXpLSUxHTDI1ZFE0CnFpYUN1eGZQejJMblZPd1ROeUth
-            dklZYVVNa1ZNZ1d4dW9vMCsvQWp1RkEKLS0tIERxakx5L0JrQitib1EyNDRMbDQ5
-            Z3hDWUFEazdxczVhaHJYK3VZeEJSSDgKkw9T4ZuT+VHIF4WopqRHt8vW30kOysJ3
-            vOq6EZ3Fqkgmoxm69Zp2gFnuE9GZIBy3VPQVLU2k6dZGJ3IvmLYeBA==
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSB1OUdjSHgvOC81d1kxbnIv
+            SlNMbzVPY0VGeFBzN2Z0VzZPQjhZVkN2RVZFCitxTHBtUTJpTURWaWUrSGJRb1lh
+            Zi91WktPZkdtVERMdkNpSytSTHlhYWsKLS0tIHJWTHR6TFQrVXZ1U2dlUmI2Z0NX
+            WXRVRVVIV3hrQUR3cEFpOTRhWWVVYVUKGD+dBn5pEFekiwn0EAHTPydwKS6kRkz3
+            RgakGqUKbkib5iEc1aNoyxFT2WM4S9WFx9zgSuGwFplRi87/19KNvA==
             -----END AGE ENCRYPTED FILE-----
           recipient: age19gfn2yedg76dmztm4hncr7vf3r3c9j0qpt4rap7y7gersjk4m3ks2lhd0e
         - enc: |
             -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSA0THJzMFBTTCtDMWRmZ25M
-            dU55OVhBb0trWWRUNlArTnEzRjhiYngvRENNCjF4d0M5NlYyQW50TTdMRXpuUjRr
-            M1NwV05JOHV6T2cxT2FheVpuZ0w2T0kKLS0tIFBxdlVpVEoxOUpSWjk1ejRsK1NM
-            V1UwTU1scG91L2FIemtwSW5JbFlmeG8K/1WIlaIidy3x3ptoRpS/DG88064LQ6Mq
-            GbfB0jfq5PILDQMMuZu5oIBY31SxwnhZ02Ns7gA67kgNIRSCmk9WyQ==
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBuN09aWHpKRTgwRVVranRa
+            Z1dKMjF1UUxVR0RGNkhQMEpPekk5eCtQT2dzCi9CQ0s5bERaR1FDQmcyU2tzS1cz
+            aENSS3MzZ0VVdndKc1g1UTVOM1Vnam8KLS0tIDdZL2p5eU8rMmRHUUhSdDJtaDEz
+            eXFkZUZtVEJFdFQzYk44ZFBCalZTL2sKMb2HbPuPNw12h6HldaIBI9ZGv6X7plrn
+            lyu7xcFoD5d3REu6TsEIQd1PgqQGr63/pbQ+6fteypPQrdSeBP5sqg==
             -----END AGE ENCRYPTED FILE-----
           recipient: age1ll6hj5ggruetgjwjfnplpn5xtq35uhlcdflksx3xmnjm6s3uad9sz70jkf
         - enc: |
             -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBmRURQVGw1a1E1MkIzV2pa
-            RG5HSkM0c0huUGVWcnFZOGlacGlGOHFMTVFrCm5OS09HRFc3TGVUYmtzTStxL0Q5
-            N2hRMEcxUE9MTmZXL0wvME5EZXF1Z00KLS0tIHdHMVVHcTZzMmdXU0s4QlVqSS9Y
-            ZUVmcWhPaURIUFJGR0V4bUZwKzM1bm8KlvGMNEClbLlfvJqNQHhd0dI4ihShLChF
-            GI/fydgrBruw3Otv6KLZu3CBC7iNcKlvZxz+YGD2qbicmyQ5hAhDSQ==
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSAxY3ROYmJmUDlnVVN1bStZ
+            dkloZDc3NVpnRUQwRzFYbFhIYTMxZVppZFdNCnVQVDJJSWJRT0pSeXJkdjVYWEtM
+            VFJSaXJEeUVMVGJidDlmTUhLZW1pTUEKLS0tIEVYb2gyMThBTDNUUFlNdVZyYzVm
+            VlAyOXdScWJjVFJMVDlrcTFIMEwybzgK6v/+a62q1F1CLH2llwtfk31ZutTIUUA2
+            yw1lO0m7gKabPHtySuz+zOQgNRx9EsnGcSXAmWZ2MXW1+m+6OpNuBQ==
             -----END AGE ENCRYPTED FILE-----
           recipient: age120le4a5l8dh3lyfgvmj3d9ksmej6ajs5mer5y7r0vfg3x9fn69dqf8xgzu
         - enc: |
             -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSA5bWpFenBlQldna3RhSFpr
-            bEJBaHJDMzM3OHlqTmozcWU0VDM1bTFUWFZzCnZtNHZjZ1U1RzNkUlBHZFozWXdt
-            VVkxQjMvTDJtbFZnclpkUEd4TEVmNTAKLS0tIFlhV2ZSSzJLRVNoMmFyVktDOElR
-            YUxqZUFoY1ZWeGlldGplMjVQa1A5aUUKWelY6yO7Mr6dRvj4MVMbq/Z9JgrAnahz
-            BDhHqObzJrOCtfDCTWiYuP+0yvIFWItMWhGSMw9MwwivvwnrEa+ZuQ==
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSA1SzBlOGVqL0h0Q2N0eDAw
+            QTNROHRVeVNOMDdLZTN2ZXNyNERMOGxEbUNFCjU2ZXJwb3ZlSEtoV2dvbVZjMWI4
+            c0NLbm9TaGtlNFZpeEFuQVVabmsvbGsKLS0tIEVRMUpZbmlTZHU0M09Cd2lpaGpl
+            akJzWGg1c0RHblNueTJMaFd3SytjeFkKUN00FC0MYc7MC8UMEOFtTHWMOh/Ratyd
+            e8AvxBrGnEEKjm7PtCKOnFF7l5srBIsnuhjcyGCq8uTlE/6XS8mvBQ==
             -----END AGE ENCRYPTED FILE-----
           recipient: age1qz9d4ka4xgexujyd247s7lp737sulp5fhxl5d65fj2ykvc4j4edqrsdks8
         - enc: |
             -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBiK2hKb2VaVnoyaEVYUHZZ
-            OWVUSGtONGs5dEljTjJQdlhEcjNjdjViT2pVCkpaOHVZMlpXOFRveVlMeXZqWmoz
-            ZHJRQTR2dmJQSEozeTRGMEdUdFlmZ2MKLS0tIERWS1RVdW1jQytBZzlkb3puNjhH
-            ZjdlZmtzNXVOQ25DeCthUzhRRm1MT2cKaxc7zGm57iJFSeYc2IPqF4Eaxa44nR37
-            pWZw+erG4F9AAZ2F047q+oLKe0B8FLSF54IbcXdQhitgGNR7B2HVeA==
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSB2MWFIOHc4RDdyWEVIdDJy
+            UmtZZC9CS3l4WUlEejhkODlPb3VCc003eEdrCmlWcHJMRkpaQjI2WUpVNUozMkFE
+            MEZNakE0Y2RZOU5XZXVNY3hEaDVQRTgKLS0tIGJaWGJscTZENnRQd0NFZUpsRjhs
+            d3YrR3dkS2VsV3J4THJwTng2VVNMeDgKIG+vd3mnwalAKnJ3neucl7sQ0sgsNcAt
+            WeUuF5C6QQXNlzUQClY5dmCvJmRjUIfS/m7s1WJAJbzUfaSOokxehg==
             -----END AGE ENCRYPTED FILE-----
           recipient: age120whqj96g26lsgy4udvgsn8dc9lumh8jeu3a564fx79rjr5lxffqmrljuu
         - enc: |
             -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSA1ekhUTG5VOFErL3pFeWZM
-            RG9NVnN6NFl3bzlFeTQzdHFtZmhwem04alQ0ClpJRStObERMZ0w2V0NhR1FSeW96
-            M1d2V2NjUkUrLzN2ZVNSbGY4bll5WmsKLS0tIC94dVFQcXJ6d3pLU0VHNEFGR0ls
-            a1Q2UmNuSjVMNG5XZGZKV1VmNHFPQXcKQJrZGw/9fPnXeFZ4omrkEgrzwplhwvRW
-            i0FXuepoU353sR7enyL34qPoOdm05ivowuPKNzkq8D4i5AF6vGv+YA==
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSB6OHRNd0FZSGZ6MFEwSnU3
+            Tm1pUnoxK1Y4dGJCTk1EbldzaWlscUdzTWlJClpHcHhmVXE5WUZRaUt5TXM0TVJI
+            UkxnUXhISGtmcUhndGNQcWNVWGVlOEEKLS0tIGJMSVR3OU1oSHkzQWpMMWVYTDV2
+            enAxMzQ2NWk1Qzl6YnpVYTdydk5pSFEK/1s8Ej3QLoWPDmd3Yj0nLV1reQ5QCPZX
+            YhGlujb3rTlgxJaQCpqynf6w2Tf4dT/Wq5edE8tHnXyr/kHacpnsFg==
             -----END AGE ENCRYPTED FILE-----
           recipient: age164px2a8e48ptsf9ngtan38aa6jls4jdl26mzrgzf6sn3vcvt49hqjrgr8w
         - enc: |
             -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBoZ2lHM2RBQ3lUK216dkcr
-            Y3RrcXR3QTdFVjJRWlhpQWVFQ1cyZWNabkRFClAwRi9PSHF5ZWFSUzJuRXF3bU1R
-            b0U5TFRZaFdmR1NMS3RRT3E3M2hUdE0KLS0tIEtrUy8ydkNyVHBiOVR6WEdjV2VN
-            NVJHUVgwRkhxcmlwcFkrRlFwTEF6YVkKzXyJk0UnmUsvb+NzNVcf/gf7OEEt3P/K
-            OIGxDrGfs/zNQgeKXNbQlQ4p4jOaybG8aCmX+A4qTk6/I8yY8LTJWg==
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBrNklUU2UrN3ZTeGdYNTRw
+            cXZZVXdrUEtxWjNKaWp2cDZrQW5tVkJ0MEdjCnN4NmgxYlJNNFNXODcvUFF6aEZS
+            OUpEZkpXcU1CRDVEUlBGYVYzVXdYTEkKLS0tIGtyUDc4SjJYUFUzT3BtNnVCeTdZ
+            azJ4bk9sTWZYYWRoV1VPV0VBUzFVekEKsrD8hFi8F8ME0VO4CHAYa5N0swt5R2Bz
+            Ll6AgyEysPR3Q8dqGJnBV/b6hs2aVDyKgGjaAXlI55OxP3RgXJQ1vQ==
             -----END AGE ENCRYPTED FILE-----
           recipient: age10at8862478urh0eeuwh8hzln6ck78jgwtztgxatwqlzwagg77y5snm4xzg
     lastmodified: "2026-07-19T02:30:40Z"

secrets/nix-cache.yaml

@@ -4,29 +4,29 @@ sops:
     age:
         - enc: |
             -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBDbHd1Y1dpa2ZiQ2E1bXRP
-            SnkrWHI0V2U1eGFKY0RZamZQQjluS0hGeENZCmduUFQyd1Q5RkZGMGFoenJhNmZh
-            VmZ2OStNaFpJejFxQ2JUZXFpNThaMncKLS0tIEhJdGdQeXEzb25Nbk5YZktCWVUz
-            NUJDUWRoTkd5R2pFblZjS0NSbVR5dkkKDYeW+zRpha04/CasFM91K6v1PpkNGHRu
-            qAoKs9KSg9VxS7ya8RuLmylKRdpPkupm/8SXIJvQuCXp5LWmNJ4zkA==
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBmOHlPcGZvN3o5aEZCcFdz
+            WlYydFdoQ0ZHbElMdTRkZWljMmoxTHZqNjJZCnE3cmgzKzZya3FROEczbHVveDND
+            VnEzRW12cnRKdzhkZm5uTXpkTEtrNUEKLS0tIHFDbkc4Mk4wVlM2R29zZXYwR2Ri
+            ODBML1p4eUZiZldYUERQTUhTU1llV0UKxjvH6zbW6wKghzR1o34CyKPEa2FqZmo0
+            PxgqyuXkIwas9soXVAkScx7ElaV09Fjaj+mDrKwi4a+DwdoSP7czyA==
             -----END AGE ENCRYPTED FILE-----
-          recipient: age10nd382a9klsn2mrs60emdtsxe43pht3a0m9p29phfrhy0wfyt3vsq9r667
+          recipient: age1njap586hc0q43kr03g6c8eqhdsmk8zcafkl3f83xwlc2gqhlmfgs4tmwad
         - enc: |
             -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSB4UktiUUdmd092bnZMdFMz
-            Q05xVlhnNzhPZUY4TjF5bjRCbklacTdJd1RBCnJ4bEVMaWRLZExIUFVEUDBXTnlV
-            MDU4WUk5VlJjdlhVUVpzZXlnWHhqTjQKLS0tIE9iclhGVElPcU9OLzF0bEVjMjVp
-            YzlQTGFYZEhLdTk3N3ZramVjVGRXREUKjOjqO/jX5iEKN43WiJ8qS/1mDfxdj8uO
-            K7Yyc/Yj0qMvGwLNzphjmbT29P7dXk4Ht4TedqCd+8DfhpOgLVIaSA==
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSB0VDBXYUZNbnpEZHlqV05C
+            WWxQZjVYcWlZeXlGc0RiaUpERzR0T21CWWtBCkM0dW5kYlFNK1RGSzRudFZ2Z0t3
+            aVBreElGM1BIT0RzQkxTVTA3S2NhQncKLS0tIERyTU8zWWRTRm95SmRZQ1BhalVV
+            SVdBajN1V1BuM2s4K216S3c0VHczNlkKM5jvsSEfCBA5uZRjBJNbM91lLRQkj+jK
+            rM5uSfGLTvSjPgXIMIq03OXxH1CE7GoKxAPwFrJdAFMMQcutIethhw==
             -----END AGE ENCRYPTED FILE-----
           recipient: age120le4a5l8dh3lyfgvmj3d9ksmej6ajs5mer5y7r0vfg3x9fn69dqf8xgzu
         - enc: |
             -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBjaXpvQU9yRUc3ektPMmU5
-            Q0xLWU9mYXVOeTVBNGNsZzJPa1lkVlRUZHlvClhoSVV6YjB1Q3pTTzVvNFlNYkU4
-            Y2RrbFk5SUFKSDVjeFU0Wlc2aGFUMFUKLS0tIDlVeXM4WWRUakg4Zk5mcjdJL3VC
-            S1k5eFBpVnREQlZwYllpeTNhWW5GS1EKi2sMwyJJ0D8acjCZmxlcwdU1sglBuxR7
-            2SEMsctdGC+5E3ilPXvPpZ5RONZHbXxn6kQRBlBv6AJERpGDzsfgfA==
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSAvbk9tRE9jYkpxNThQeElH
+            dWpKYThDb1ZkUWtMWlRxc2tYbjhBbEFEcWtVCkNiK0NBRko2TkJQdUVtdGtHNGcv
+            andSaUlKSFA4THRyZXNTYmI0Yk5WbmsKLS0tIHlQTUtpWDdPeTVZL0M1RElRdFNk
+            QWlGdFo5NkZWSmY0YXdpNzNUQnlsK3MKtzC0bM7Ek+K73nMranOA1Mc98RUnYnq1
+            hAt0QEFKWK4QVKubaN/rG3AzE0U7qPKWHTzoxgnAiL3WyV9teLW+iA==
             -----END AGE ENCRYPTED FILE-----
           recipient: age164px2a8e48ptsf9ngtan38aa6jls4jdl26mzrgzf6sn3vcvt49hqjrgr8w
     lastmodified: "2026-07-19T23:30:21Z"

secrets/server.yaml

@@ -3,20 +3,20 @@ sops:
     age:
         - enc: |
             -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBxaFZURjAxMGRJZEJ5MW1x
-            ZjVwWEQrQlkwNmRibVNiL2RpTTFLeUVDQ3hRCkVIamVnZkM1MnlueloxMHVFQnBF
-            RjV2bnUrZUo4WGZJTmR4Y0xITkxRUkUKLS0tIGlJdVQ5MFBubVhxRUVMWW0wSGpP
-            UGdKNUNPYW9nek1UZ0tWbXd3QVNUNDgKIHOiKelITQdH5R4Nc3WF7mzz15D1f9on
-            VaTdr5qkf8LNNvPI0fxsXA9is5cqeg+KbDRHtUumEhNp6Zrf8zWBkw==
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBURmMzN3hrSlNrUkkvVWNl
+            L3M1dEhWeW14N0RFNVRPci9QK1YyTFdqRVVJCk5WaWswT2NicldkYzZjbVhYU2xu
+            MGFsNmUzeTN2TS9wOEdvRURpVUVYZXMKLS0tIDZ6MEdPTVhCaTQ2UXFWTUFtc0pm
+            MFlJb0c2WXJtMGRLZEZYY0pZWWpFWm8K/mlYZIe8UC0QU+1mq3NtrtTF5b2m5hCK
+            +K0QiZLTKmmDcr4bRhZ32VE7R7GRwtMNnOP/mElZvPAyWyHHhRiOHg==
             -----END AGE ENCRYPTED FILE-----
-          recipient: age10nd382a9klsn2mrs60emdtsxe43pht3a0m9p29phfrhy0wfyt3vsq9r667
+          recipient: age1njap586hc0q43kr03g6c8eqhdsmk8zcafkl3f83xwlc2gqhlmfgs4tmwad
         - enc: |
             -----BEGIN AGE ENCRYPTED FILE-----
-            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSA3N0hvV01naytDSWVwK1B1
-            MXM1ZkdpaVc2Q3FPV2VBcC83WmcvSjdGUGgwClJGSXZ6YW5JeFlValNJbjVhK29u
-            bUFqN2dRQTI4ZkwyeXNWYk5JeWVJRXcKLS0tIDlMMkNBUnNUSTJwVVFmc2dlcEZS
-            VGQ1VHR2dXB0M3RsalppVWxiUUROM0UKZM/4QDTam3LDTzjnDs41Ije50R7Q7GC4
-            IZbUZjs72rBzY8IkJDbN9JidadEc4NAtMOJwXiJbpZGiCBNfc8+SXw==
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBURHlUL0RNMUtNallEcG5p
+            eG4xby8yVzdQUTBaNkl4ano0YjBMcDd0Wm5NCkZvaXNPZm9wemJkMmNSdGdOaTI4
+            Z1RwUnhiRUpCMWZaeWtlSVBmNW5KOXMKLS0tIDk0R0k3ZHczTFNCWUZxSWF0M0FJ
+            MGlZMmtuSFYrcG1meDNMWDNqSjFxcE0KDu2dAc0gqmmPkpbpBe4YohM7rYmUwEkI
+            V2FUQwjlvh50svtjCVdYbx2xuq4sQLnKelk/q1onLw60FwsVfzD8sQ==
             -----END AGE ENCRYPTED FILE-----
           recipient: age1ll6hj5ggruetgjwjfnplpn5xtq35uhlcdflksx3xmnjm6s3uad9sz70jkf
     lastmodified: "2026-07-19T02:30:40Z"

variables.nix

@@ -19,6 +19,15 @@
 
   remoteBuilderUser = "nixremote"; # remote builder SSH user
 
+  # nix-cache's own SSH host public key (not a secret — the private half
+  # never leaves the host). Wired into every client's
+  # programs.ssh.knownHosts by modules/nix-cache/remote-builder-client.nix
+  # so distributed builds don't hit "Host key verification failed" on a
+  # fresh client that has never manually ssh'd to nix-cache before. Update
+  # this if nix-cache's host key is ever rotated or the host is rebuilt
+  # from scratch.
+  nixCacheHostKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHrMKZlIGUd3pH9G3AqbsruqUGjxIXMAZw52u9MwiBCn lxc-nix-cache";
+
   # Public keys authorized to SSH in as remoteBuilderUser on the nix-cache
   # host (modules/nix-cache/server.nix) — one per client host that's allowed
   # to use it as a distributed builder.
@@ -147,20 +156,4 @@
     keep = 20; # number of rotated logs to retain before deleting the oldest
   };
 
-  # Flake targets with a real, currently-running deployment somewhere —
-  # matches README.md's Hosts table "(real, deployed)" annotations; update
-  # both together. Not consumed by any NixOS module (nothing in the actual
-  # system config should behave differently because of this) — it's read
-  # by scripts/create-proxmox-resource.sh to refuse creating a same-identity
-  # duplicate of an already-deployed host (shared hostName/hostId) unless
-  # you explicitly pass --allow-duplicate-host.
-  deployedTargets = [
-    "linode-minimal"
-    "proxmox-minimal"
-    "proxmox-nix-cache"
-    "proxmox-server"
-    "proxmox-docker"
-    "proxmox-gui"
-    "proxmox-pxe-boot"
-  ];
 }