Dynamic DNS Update Toolkit

Compose and send dynamic DNS update transactions for a single zone using queued operations with prerequisites and deletions.

Capabilities

Conditional host replacement

• When given a hostname, expected IPv4 address, and new IPv4 address, build a dynamic update that asserts the expected address is present (or absent when not provided) before replacing the A record with the new value and TTL; the returned summary marks the change as applied. @test
• If the expected address is supplied but not present, the update should be blocked by the prerequisite and the summary should show no applied changes. @test

TXT cleanup with prerequisite

• Accept a hostname and optional token string; when a token is provided, assert that one TXT record exactly matches the token before deleting all TXT data for that hostname. @test
• When no token is provided, delete all TXT data for the hostname without touching other record types. @test

Batched submission

• Queue multiple operations and emit a single update message for the zone with prerequisites listed before updates, no question section, and TTLs/names matching the queued inputs. @test
• Send the composed update to the configured nameserver host/port using UDP with a TCP fallback on truncation; return a dictionary containing the response code text, counts of added and deleted records, and whether any change was applied; raise a timeout error when the operation exceeds the configured deadline. @test

Implementation

@generates

API

class DynamicUpdater:
    def __init__(self, zone: str, server: str, port: int = 53, timeout: float | None = None): ...
    def queue_replace_a(self, hostname: str, new_address: str, expected_address: str | None = None, ttl: int = 300) -> None: ...
    def queue_delete_txt(self, hostname: str, required_token: str | None = None) -> None: ...
    def build_message(self):
        """Return the dynamic update message built from queued operations."""
    def apply(self) -> dict:
        """Send the update and return {'rcode': str, 'added': int, 'deleted': int, 'applied': bool}."""

Dependencies { .dependencies }

dnspython { .dependency }

Provides dynamic DNS update helpers and transports.