Fix duplicate-host check reporting false SSH failures

The remote bash script run over SSH ended with a for-loop whose last
statement was `[[ "$n" == "$target" ]] && echo ...`. When the last
VM/CT checked on the node didn't match --host, that test evaluated
false and became the exit status of the whole remote script (1) --
which the wrapper then misreported as "couldn't reach the node",
even though SSH connectivity and the check itself were both fine.
The actual signal is the script's stdout, not its exit code, so end
it with an explicit exit 0.

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

CLAUDE.md

@@ -93,9 +93,10 @@ 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
+  Refuses to create a target whose host identity already exists live on
-  deployment elsewhere (`variables.nix`'s `deployedTargets`) unless
+  the node (checked directly via `qm`/`pct`, not any file in this repo)
-  `--allow-duplicate-host` is passed. `--dry-run` throughout both modes.
+  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.

README.md

@@ -18,20 +18,23 @@ list:
 
 | Target | Purpose |
 | --- | --- |
-| `linode-minimal` | Minimal NixOS host profile on a Linode VPS (real, deployed) |
+| `linode-minimal` | Minimal NixOS host profile on a Linode VPS |
-| `proxmox-minimal` | Minimal NixOS host profile on Proxmox (real, deployed — previously the flat `nix-minimal` target) |
+| `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 (`lxc-nix-cache` is the real, deployed one — previously `proxmox-nix-cache`, itself previously the flat `nix-cache` target) |
+| `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 (`proxmox-server` is the real, deployed one — previously the flat `server` 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 (`proxmox-docker` is the real, deployed one — previously the flat `docker` 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 (`proxmox-gui` is the real, deployed one — previously the flat `nixos` 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 (`proxmox-pxe-boot` is the real, deployed one — previously the flat `pxe-boot` 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 (no deployed target yet; `lxc-tailscale-exit-node` is the one planned for actual use) |
+| `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
+Which variant of a given buildtype is actually deployed isn't tracked
-`variables.nix`'s `deployedTargets` — keep both in sync when a deployment
+anywhere in this repo — that's live infrastructure state, not something a
-changes. `scripts/create-proxmox-resource.sh` reads that list to refuse
+committed file can keep accurate, and it changes independently of the code.
-creating a same-identity duplicate of an already-deployed host by accident.
+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

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
@@ -56,10 +58,11 @@ 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
+  --allow-duplicate-host        Required if a VM/CT identified as --host
-                                deployment elsewhere (variables.nix's
+                                already exists on the node (checked live via
-                                deployedTargets) -- otherwise refused, since
+                                qm/pct, not any file in this repo) --
-                                it'd share that host's hostName/hostId.
+                                otherwise refused, since it'd share that
+                                host's hostName/hostId.
 
 Modify mode (reconfigure an EXISTING resource -- requires --modify):
   --modify                Switch to modify mode.
@@ -286,25 +289,58 @@ 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 ----------
+# --- refuse to duplicate a host that's already live on the node ---------
-# Checked by hostName, not exact flake target: proxmox-server being
+# Queries the node itself (qm/pct's own name/hostname config), not any
-# deployed also blocks --type lxc --host server, since both would carry
+# static list in this repo -- a file can't track whether a resource still
-# the same hosts/server/host.nix identity (hostName, hostId).
+# actually exists, and this used to be checked against variables.nix's
-if [[ "$allow_duplicate_host" -eq 0 ]]; then
+# deployedTargets, which drifted stale (it kept naming a VM as "the real
-  deployed_targets_json="$(nix eval --json --no-use-registries --no-accept-flake-config \
+# deployment" well after that VM had been destroyed, blocking its own
-    --file "${repo_root}/variables.nix" deployedTargets)"
+# redeploy) until that list was dropped in favour of this live check. This
-  for dt in $(echo "$deployed_targets_json" | jq -r '.[]'); do
+# only catches guests identified with the default --name (== --host, what
-    dt_hostname="$(nix eval --raw --no-use-registries --no-accept-flake-config \
+# this script itself always uses unless --name is overridden) -- a guest
-      "${repo_root}#nixosConfigurations.${dt}.config.networking.hostName" 2>/dev/null || true)"
+# manually renamed on the node afterwards wouldn't match, but nothing here
-    if [[ "$dt_hostname" == "$host" ]]; then
+# creates guests that way.
-      echo "ERROR: '${host}' already has a real deployment (${dt}, per variables.nix's" >&2
+if [[ "$allow_duplicate_host" -eq 1 ]]; then
-      echo "deployedTargets). Creating ${flake_target} would share its hostName/hostId --" >&2
+  echo
-      echo "refusing by default. Pass --allow-duplicate-host if you really mean to spin" >&2
+  echo "--allow-duplicate-host: skipping the check for an existing '${host}' on ${node}."
-      echo "up a separate test instance of this host (it'll still get its own distinct" >&2
+elif [[ "$dry_run" -eq 1 ]]; then
-      echo "sops key and VMID, never touching ${dt})." >&2
+  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}'"

variables.nix

@@ -156,20 +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"
-    "lxc-nix-cache"
-    "proxmox-server"
-    "proxmox-docker"
-    "proxmox-gui"
-    "proxmox-pxe-boot"
-  ];
 }