# Oikos metrics stack — Prometheus LXC (planned)

Lifecycle state: **planned** (see [seeds/ontology.yaml](../seeds/ontology.yaml)
lifecycle). No LXC exists yet — this is the plan doc that state requires
before provisioning starts. Do not add a host entry with a guessed
`pve_id` until the LXC is actually created; Proxmox assigns the real ID
at `pct create` time.

## Why

Week-3 reliability layer (see [OIKOS.md](../.agents/OIKOS.md)) wants trend
signals — "disk full in ~9 days at current rate", temperature creep —
which need a real time-series store. The Go scheduler
([internal/scheduler/scheduler.go](../internal/scheduler/scheduler.go))
currently does point-in-time threshold checks only; Prometheus is the one
new piece of infrastructure the 30-day roadmap calls for.

## Note: LXC 131 is teddycloud

The drift detector (`drift` check kind in `check_defs`) found
`pve_id 131` live on hubris — this is **teddycloud** (`lxc:teddycloud`),
which is now documented in `seeds/knowledge.yaml`. The pve_id range is
fully accounted for (101-134). Next available VMIDs start at 135.

## Plan

- **Host:** hubris (per the earlier decision: new LXC, not co-located).
- **Role:** `metrics` (Prometheus + local TSDB retention; no Grafana yet —
  the Week-4 Oikos Console renders its own sparklines from the Prometheus
  HTTP API, per the plan's Week-3 scope decision).
- **Networking:** LAN + mesh-gated only, no public ingress (matches
  `mcp` / `secrets-issuance` `MESH_SUBNETS` pattern) — Prometheus
  exposes host/service metadata that shouldn't be public.
- **Scrape targets:** node_exporter on hubris and strong (Proxmox hosts)
  + any LXC the scheduler needs disk/temp trend data from beyond what
  `pct`/`df` already gives (start with hubris + strong only; expand only
  if a specific signal needs it).
- **Storage:** local LXC rootfs is sufficient (metrics-only workload,
  short retention — no `/mnt/library` mount needed).

## Provisioning steps (once pve_id is assigned)

1. Add entity to `seeds/inventory.yaml` with state `planned` and the
   assigned pve_id. Run `oikos seed` to ingest.
2. `pct create <new-id> ...` on hubris — next available PVE ID is 135.
3. Install Prometheus + node_exporter (Debian package or binary release —
   decide at implementation time; no strong preference recorded here).
4. Point node_exporter at hubris + strong (either install locally on each,
   or scrape via SSH-tunneled metrics — install locally is simpler).
5. Transition to `active` via `PATCH /api/v1/entities/{slug}` or
   operator approval through the execution flow.
6. Add a `prometheus` check kind to `check_defs` in the scheduler
   (`internal/scheduler/scheduler.go`) so trend signals can query
   Prometheus `rate()` alongside the current SSH `df` probe, giving
   "full in ~9 days" predictions instead of only point-in-time
   percentages. Register a `prometheus` check def via `POST /api/v1/checks`.
7. Run `oikos export` to regenerate `seeds/inventory.yaml` for git.

## Open question for the operator

Package choice (apt `prometheus` vs upstream binary release) and exact
scrape interval aren't decided here — pick at implementation time based
on what's easiest to keep patched via MCP `request_execution(action="apt_upgrade")`.

## Changelog

### 2026-07-08 — Go references updated
Replaced Python references (`oikos/scheduler.py`, `oikos/drift.py`,
`bin/homelab`, `homelab client add`) with Go equivalents: `internal/scheduler/`,
`check_defs` drift kind, MCP `request_execution`, `seeds/inventory.yaml`.
LXC 131 identified as teddycloud (PVE range 101-134 fully accounted for).
