# Hecate

Hecate is the host-level bootstrap and power-protection service for Titan.

It runs on `titan-db` and handles:
- Staged **startup** (including Flux/Gitea bootstrap deadlock fallback)
- Graceful **shutdown**
- UPS-driven automatic shutdown decisions based on discharge/runtime
- Multi-UPS operation via multiple Hecate instances (for example `titan-db` + `tethys`)
- Full hardware poweroff sequencing after graceful Kubernetes shutdown

## Why host-level

A service inside Kubernetes cannot start a cluster that is fully down.
Hecate runs outside the cluster under systemd, so it can always orchestrate bring-up.

## Commands

- `hecate startup --config /etc/hecate/hecate.yaml --execute --force-flux-branch main`
- `hecate shutdown --config /etc/hecate/hecate.yaml --execute`
- `hecate daemon --config /etc/hecate/hecate.yaml`
- `hecate status --config /etc/hecate/hecate.yaml`

## Manual install on titan-db

```bash
git clone git@gitea-admin:bstein/hecate.git
cd hecate
sudo HECATE_ENABLE_BOOTSTRAP=1 ./scripts/install.sh
sudoedit /etc/hecate/hecate.yaml
sudo systemctl restart hecate.service
```

The installer is idempotent:
- Re-runs safely on every update
- Preserves existing `/etc/hecate/hecate.yaml`
- Ensures required dependencies are installed (`kubectl`, `nut-*`, `ssh`, `go`, etc.)
- Installs/refreshes systemd units and enables boot-time self-update
- Applies declarative NUT + udev UPS configuration by default (can be tuned via env vars)

Installer knobs (optional):
- `HECATE_ENABLE_BOOTSTRAP=1` enables `hecate-bootstrap.service` on this host.
- `HECATE_ENABLE_BOOTSTRAP=0` disables it; default `auto` preserves current bootstrap enablement state.
- `HECATE_MANAGE_NUT=0` skips writing NUT/udev files.
- `HECATE_NUT_UPS_NAME` (default `atlasups`)
- `HECATE_NUT_VENDOR_ID` / `HECATE_NUT_PRODUCT_ID` (defaults `0764` / `0601`)
- `HECATE_NUT_MONITOR_USER` / `HECATE_NUT_MONITOR_PASSWORD` (defaults `monuser` / `atlasupsmon`)

Bootstrap now (without reboot):

```bash
sudo systemctl start hecate-bootstrap.service
```

## Preconditions on titan-db

- `kubectl` installed and configured (`kubeconfig` path in config)
- SSH reachability to all cluster nodes
- Remote sudo rights to run:
  - `systemctl start/stop k3s`
  - `systemctl start/stop k3s-agent`
- UPS telemetry available via NUT (`upsc`)

## Multi-UPS topology

Recommended:
- `titan-db` runs Hecate as the shutdown coordinator (local UPS target + local shutdown execution).
- `tethys` runs Hecate with local UPS target and forwards shutdown triggers to `titan-db`.
- If forwarding fails, fallback local shutdown can remain enabled.

## Config

See `configs/hecate.example.yaml`.

UPS auto-shutdown trigger uses:
- runtime threshold = `runtime_safety_factor * estimated_shutdown_budget`
- default safety factor `1.10`
- debounce across multiple polls to avoid noise

Estimated shutdown budget is derived from historical successful shutdown runs (`/var/lib/hecate/runs.json`) with default fallback from config.

Power metrics:
- Hecate exposes Prometheus metrics on `:9560/metrics` by default.
- This is intended for a dedicated Grafana power dashboard and a high-level overview row.

## Notes

- Default behavior for `startup` and `shutdown` is dry-run unless `--execute` is set.
- `hecate-bootstrap.service` is enabled to run at host boot and perform staged startup automatically.
- `HECATE_ENABLE_BOOTSTRAP=1` enables `hecate-bootstrap.service` (recommended on `titan-db`; keep disabled on non-coordinator hosts).
- `hecate-update.timer` runs on boot and periodically to pull latest `main` and reinstall Hecate declaratively.