# Host Overview Info Section

**Date:** 2026-05-10  
**Status:** Approved

## Summary

Add an always-visible info section to each host card on the Host Overview (`/plugins`) page. The section shows owner, managers, agent version/type, last packet timestamp, and the host's effective alert thresholds. The fields `hbc_version` and `hbc_type` are moved out of the `os_info` plugin accordion into this section.

---

## Backend: New API Endpoint

**Route:** `GET /api/0/hosts/{hostname}/info`

**Auth:** Same as other per-host endpoints (`_can_view_host`).

**Response schema:**

```json
{
  "owner":       "alice",
  "managers":    ["bob", "carol"],
  "hbc_version": "5.3.0",
  "hbc_type":    "full",
  "last_packet": 1746894000.0,
  "thresholds": [
    {
      "metric":    "cpu_monitor.cpu_percent",
      "warning":   80.0,
      "critical":  95.0,
      "operator":  ">"
    }
  ]
}
```

**Field details:**

- `owner` — `host.owner`, or `null` if unset.
- `managers` — `host.managers` list (may be empty).
- `hbc_version` — from `host.get_latest_plugin_data("os_info")`, key `hbc_version`; `null` if no os_info data.
- `hbc_type` — same source, key `hbc_type`; `null` if unavailable.
- `last_packet` — `max(conn.lastbeat for conn in host.connections.values())`, or `null` if no connections.
- `thresholds` — list derived from `threshold_checker.get_thresholds_for_host(hostname)`, sorted by `metric` ascending. Each entry includes `metric`, `warning` (null if unset), `critical` (null if unset), `operator`. Returns `null` (not `[]`) if no `threshold_checker` is configured, so the frontend can distinguish "not configured" from "configured but empty".

**Location:** `hbd/server/http.py`, added alongside the other `api_host_*` functions. Registered as `web.get("/api/0/hosts/{hostname}/info", api_host_info)`.

---

## Frontend: Info Section

### HTML structure

Inserted as the first child of `.host-body`, before the plugin accordions. It is not a collapsible accordion — it is always visible when the host card is expanded.

```html
<div class="host-info-section" id="info-{hostname}">
  <div class="loading">Loading…</div>
</div>
```

### Fetch lifecycle

- Fetched once per host on the first expansion of the host card (same trigger as the glance/plugin data).
- Result cached in a new per-host `infoCache` object (parallel to `pluginCache`).
- On subsequent expansions the cached data is rendered immediately without a new request.

### Rendered layout

Two logical areas rendered client-side from the JSON:

**Meta row** — a CSS-grid or simple `<dl>` showing:

| Label         | Value                        |
|---------------|------------------------------|
| Owner         | alice (or "—" if null)       |
| Managers      | bob, carol (or "—" if empty) |
| Agent Version | 5.3.0 (or "—")               |
| Agent Type    | full (or "—")                |
| Last Packet   | localized datetime string (or "—") |

**Threshold table** — rendered with the existing `data-table` CSS class:

| Metric | Operator | Warning | Critical |
|--------|----------|---------|----------|
| cpu_monitor.cpu_percent | > | 80 | 95 |
| … | … | … | … |

- If `thresholds` is `null`: show "Threshold alerting not configured."
- If `thresholds` is `[]`: show "No thresholds defined."
- Numeric threshold values rendered as-is (no units); `null` warning/critical shown as "—".

### CSS

New `.host-info-section` styles added in the `<style>` block of `plugins.html`. The section gets a subtle background (e.g. `#fafafa`) and a bottom border to separate it visually from the plugin accordions below. The meta row uses a two-column grid layout for compactness.

---

## Changes to `renderOsInfoTable()`

- Remove `hbc_version` from the `ORDER` array.
- Add `hbc_type` to the `SKIP_FIELDS` set (or the local `shown` set) so it is excluded from the os_info table.

Both fields will now appear only in the info section.

---

## Data Flow Summary

```
User expands host card
  → toggleHost()
    → fetchGlanceData(hostname)   [existing, unchanged]
    → fetchInfoData(hostname)     [new]
        GET /api/0/hosts/{hostname}/info
        → renderInfoSection(hostname, data)
          → writes into #info-{hostname}
```

---

## Error Handling

- If the info fetch fails (non-200), show a one-line error message in the info section ("Could not load host info.").
- If `hbc_version`/`hbc_type` are null (host has never sent os_info), display "—".
- If `last_packet` is null (no connections recorded), display "—".

---

## Out of Scope

- Editing owner/managers from this section (covered by existing profile/access UI).
- Editing thresholds from this section.
- Monitors list (not shown — monitors are operational, not informational in this context).