Configuration

The settings most deployments need are:

Environment variable	Default	Purpose
`RPT_DOMAIN`	`nodes.example.org`	Domain used in node lookups.
`RPT_KAFKA__BOOTSTRAP`	`localhost:9092`	Kafka bootstrap address.
`RPT_KAFKA__TOPIC`	`rpt.registrations`	Topic used by the registrars.
`RPT_PORT`	`5054`	TCP and UDP port inside the container.
`RPT_CACHE_SIZE`	`10000`	Maximum number of directory entries.
`RPT_WORKERS`	`32`	Maximum concurrent request workers per listener.

Dynaconf loads settings.toml, then an optional .secrets.toml, from the working directory. Environment variables beginning with RPT_ override those files. Use two underscores for nested settings, as in RPT_KAFKA__TOPIC.

To keep configuration on the host, mount a directory at /config and set RPT_CONFIG_DIR=/config. Files use plain TOML without environment sections. Keep credentials out of version control. See directory behavior for the remaining settings and Kafka replay details.

Full settings reference

These are Python defaults. See shared configuration for file precedence and the two registrar image overrides. Rates are per minute; TTLs, deadlines, refresh, lifetime, skew, and timeouts are seconds. Sizes count entries except HTTP body size, which counts bytes. Empty strings mean unset.

Environment variable	Python default
`RPT_HOST`	`'0.0.0.0'`
`RPT_PORT`	`5054`
`RPT_DOMAIN`	`'nodes.example.org'`
`RPT_CACHE_SIZE`	`10000`
`RPT_MAX_LIFETIME`	`86400`
`RPT_CLOCK_SKEW`	`30`
`RPT_WORKERS`	`32`
`RPT_KAFKA__BOOTSTRAP`	`'localhost:9092'`
`RPT_KAFKA__TOPIC`	`'rpt.registrations'`
`RPT_KAFKA__GROUP`	`'rpt-dns'`

MAX_LIFETIME is the largest accepted registration lifetime, not the DNS answer TTL. CLOCK_SKEW allows an event timestamp up to 30 seconds ahead of the DNS host. Synchronize clocks rather than increasing this allowance to hide clock errors. KAFKA.GROUP supplies a consumer identifier; the service still explicitly assigns all partitions on every replica and does not divide the directory between replicas.