# Configuration file

`/etc/steward/steward.yaml` says how stewardd runs. The DHCP
configuration (subnets, pools, reservations, options) isn't here; it is
in the database, changed with the CLI or the web UI.

`stewardd config --example` prints a commented file with the defaults.
Every setting is optional; unknown settings are an error. stewardd reads
the file when it starts.

| Setting | Default | |
|---|---|---|
| `listen` | `["127.0.0.1:8067"]` | addresses of the web UI and API (`host:port`). Keep them on localhost or a management network |
| `tls.cert_file`, `tls.key_file` | none | serve HTTPS with this certificate; stewardd rereads it when the file changes, or on `systemctl reload steward` |
| `tls.acme.*` | off | get the certificate from Let's Encrypt, with Jarl publishing the challenge ([certificates.md](certificates.md#settings)) |
| `jarl.server`, `jarl.token_file` (or `jarl.token`), `jarl.ca_cert`, `jarl.insecure` | none | the Jarl server Steward uses for DNS, and its token ([jarl.md](jarl.md)) |
| `trusted_proxies` | `[]` | addresses or prefixes of reverse proxies whose `X-Forwarded-For` and `X-Forwarded-Proto` are believed |
| `socket` | `/run/steward/steward.sock` | the local API socket; `""` turns it off |
| `database` | `/var/lib/steward/steward.db` | the SQLite database: configuration, leases, history, users, audit log |
| `log.level` | `info` | `debug` (every HTTP request), `info`, `warn` or `error` |
| `log.format` | `text` | `text` or `json` |
| `session.lifetime` | `12h` | how long a web UI login lasts |
| `session.idle_timeout` | `2h` | logged out after this long without use |
| `session.cookie_secure` | `auto` | `auto` (secure over HTTPS), `always` or `never` |
| `backup.dir` | `/var/backups/steward` | where `stewardd backup` writes |
| `backup.retention` | `30d` | backups older than this are deleted… |
| `backup.keep_at_least` | `7` | …keeping at least this many |

Durations are written `15s`, `12h` or `30d`.

## HTTPS

Over plain HTTP, passwords and tokens cross the network in the clear;
stewardd warns when it listens on a non-loopback address without TLS. Let
it get its own certificate through Jarl ([certificates.md](certificates.md)),
or give it one:

```yaml
listen: ["10.0.10.2:8067"]
tls:
  cert_file: /etc/steward/tls/fullchain.pem
  key_file: /etc/steward/tls/privkey.pem
```

Or keep it on `127.0.0.1` behind a reverse proxy that terminates TLS, and
list the proxy in `trusted_proxies`. With a certificate, the same port
answers HTTPS and redirects plain HTTP to it, except from the server
itself. Ports below 1024 work too: the unit
grants `CAP_NET_BIND_SERVICE` for DHCP's port 67.