AkurAI-Monitor / CLAUDE.md

Latest change c39a9a924feb8021a7355a7299f92502eb8d3e76 - Initial commit: rust-monitor v0.1.0 by Olafur Bui

# CLAUDE.md

## What this is

Minimalistic Zabbix-style monitoring for a single Linux host. Collects system metrics from /proc, tails log files, evaluates alert rules, writes alerts to a log file, and serves a web dashboard. Runs on AWS EC2 (Ubuntu 22.04).

## Build & Deploy

- `cargo build --release --target x86_64-unknown-linux-musl` (static binary)
- `./deploy.sh` — builds, uploads to VM, restarts service, healthchecks
- VM: `ssh akurai-mail` (3.94.46.219, Ubuntu 22.04, systemd `rust-monitor.service`)

## Architecture

```
nginx (TLS) → rust-monitor (:8800)
              ├─ collectors.rs  → reads /proc, inserts metrics into SQLite
              ├─ tailer.rs      → tails log files, inserts into SQLite
              ├─ alert.rs       → evaluates rules, writes alerts.log
              ├─ routes.rs      → API endpoints for dashboard
              └─ ui/            → static HTML/CSS/JS dashboard
```

## Source Layout

- `src/main.rs` — tracing init, config, spawn background tasks, axum server
- `src/config.rs` — env var config (LazyLock)
- `src/db.rs` — SQLite init + with_db() accessor
- `src/schema.rs` — CREATE TABLE statements + seed alert rules
- `src/collectors.rs` — CPU/mem/disk/net/load/uptime from /proc
- `src/tailer.rs` — log file tailing (seek-to-end, poll new lines)
- `src/alert.rs` — alert rule evaluation + log file writer
- `src/routes.rs` — API: /api/health, /api/status, /api/metrics, /api/logs, /api/alerts

## Environment Variables

| Variable | Default | Description |
|----------|---------|-------------|
| `MONITOR_LISTEN` | `127.0.0.1:8800` | Bind address |
| `MONITOR_DB_PATH` | `./data/monitor.db` | SQLite path |
| `MONITOR_STATIC_DIR` | `./ui` | Static UI files |
| `MONITOR_ALERT_LOG` | `./data/alerts.log` | Alert output file |
| `MONITOR_LOG_FILES` | `/var/log/syslog,/var/log/auth.log` | Log files to tail |
| `MONITOR_INTERVAL` | `60` | Collection interval (seconds) |
| `MONITOR_RETENTION_DAYS` | `30` | Metric retention |
| `MONITOR_LOG_RETENTION_DAYS` | `7` | Log retention |

## Constraints

- Binary MUST cross-compile with `x86_64-unknown-linux-musl`
- Release profile: opt-level=z, LTO, strip, panic=abort
- No auth — runs behind nginx on localhost only
- Static UI: plain HTML + vanilla JS, no build step