# dnstt_exporter

Prometheus exporter for DNSTT client/session metrics.

`dnstt_exporter` observes DNSTT DNS traffic on a local Linux host and exports
aggregate Prometheus metrics. It does not proxy, terminate, or configure DNSTT;
it passively decodes DNSTT session IDs from DNS query names.

## Usage

```sh
sudo dnstt_exporter \
  -dnstt.domain tunnel.example.com \
  -dnstt.port 53 \
  -web.listen-address :9713
```

The exporter needs permission to open an `AF_PACKET` raw socket. Run it as root
or grant the binary `CAP_NET_RAW`.

Metrics are served at `http://127.0.0.1:9713/metrics` by default.

## Metrics

All DNSTT metrics use a `domain` label:

- `dnstt_active_clients`
- `dnstt_peak_clients`
- `dnstt_queries_total`
- `dnstt_bytes_in_total`
- `dnstt_bytes_out_total`
- `dnstt_sessions_total`

## Development

```sh
go test ./...
go build ./cmd/dnstt_exporter
```