From ca193ad52b2ee2985af079be0159cc679c914f02 Mon Sep 17 00:00:00 2001 From: Tim Keller Date: Thu, 27 Aug 2026 14:16:02 -0500 Subject: generate the dashboards at build time instead of committing them The JSON is machine-written and the generator beside it is the only source of truth, so committing both only created a way for them to drift -- which is what the dashboards-current check existed to police. modules/dashboards.nix now runs gen_zfs.py / gen_smart.py in the derivation, so a stale dashboard cannot be built at all and the check is gone. Note there is no third option: flakes copy only git-tracked files into the store, so a gitignored dashboards/*.json cannot be read from disk either. It is generate, or commit. Verified equivalent -- both generated dashboards are byte-identical to the JSON this commit deletes. Adds a dashboards-nonempty check. Factoring the shared jq invocation out first introduced a bug it caught: the multi-line string ended in a newline, so the callers' `< $src > "$out"` landed on a line of its own as a separate command, truncating every dashboard to zero bytes while the build still succeeded. All four provisioned dashboards were empty. jqFixup is now a single line, and the check asserts each dashboard is non-empty and has a title, uid and panels. Both failure modes are exercised: an empty dashboard and one with no panels each fail the check. It also asserts it found four files, because the first version globbed *.json against linkFarm entries named without the suffix and passed vacuously. Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_01JKczN1f66kmLxNBLX37voQ --- README.md | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'README.md') diff --git a/README.md b/README.md index 7bcea7f..9014e1b 100644 --- a/README.md +++ b/README.md @@ -17,8 +17,7 @@ What *has* been checked: - every dashboard query executed against a real Prometheus fed fixture data - `promtool` over the recording rules and the generated scrape config -- `nix flake check`: both modules evaluate, and the committed dashboard JSON matches what - the generators produce +- `nix flake check`: both modules evaluate, and both dashboard generators run - the collectors run against mock `smartctl`/`zpool`/`zfs`, and partially against real hardware @@ -225,21 +224,23 @@ modules/ dashboards.nix builds dashboard JSON into a provisionable form packages.nix the two collectors as ordinary packages collectors/*.py the collectors themselves; runnable by hand -dashboards/gen_*.py dashboard generators -dashboards/*.json generated, committed, checked +dashboards/gen_*.py dashboard generators; the JSON is built, not committed rules/smartctl.yml Prometheus recording rules ``` ## Working on it -Dashboard JSON is **generated** — edit `dashboards/gen_*.py`, never the JSON: +The ZFS Pools and Drive Health dashboards are **generated at build time** from +`dashboards/gen_*.py`; no JSON is committed, so there is nothing to keep in sync and no +way to ship a stale dashboard. To see what a generator currently produces: ```sh -python3 dashboards/gen_zfs.py > dashboards/zfs-pools.json -python3 dashboards/gen_smart.py > dashboards/smart.json +python3 dashboards/gen_zfs.py | less +nix build .#nixosConfigurations..config.system.build.toplevel # or just deploy ``` -`nix flake check` fails if you forget. +(Flakes copy only git-tracked files into the store, so "gitignore the JSON and read it +from disk anyway" is not an option — it is generate, or commit.) The collectors are plain scripts taking `--output PATH`, so you can see exactly what a machine reports: -- cgit v1.3.1