# Pi Monitoring Architecture

## Goal

Use Raspberry Pi as lightweight control/observability plane for Docker hosts in this project.

## Topology

```text
                 +------------------------------+
                 | Raspberry Pi (ops node)      |
                 | Portainer + Grafana          |
                 | Prometheus + Uptime Kuma     |
                 +---------------+--------------+
                                 |
                     Portainer Agent (9001)
                +----------------+----------------+
                |                                 |
      +---------v---------+             +---------v---------+
      | Unraid Docker host|             | Fedora Docker host|
      | Gitea primary     |             | Gitea backup      |
      +-------------------+             +-------------------+
```

## Data paths

- Pi local metrics: `node-exporter` + `cadvisor` -> Prometheus -> Grafana
- Remote host control: Portainer -> remote `portainer_agent`
- Availability checks: Uptime Kuma -> HTTP/TCP checks for Gitea and other services

## Persistence

All service data is stored under `OPS_ROOT` (default `/srv/ops`) on SSD.