Catalog Zones (RFC 9432)

Starting with the PowerDNS Authoritative Server 4.7.0, catalog zone support is available.

Supported catalog versions

Catalog version Producer Consumer
1 (ISC) No Yes
2 (RFC 9432) Yes Yes

All the important features of catalog zones version “2” are supported. There are however a few properties where support is limited:

  • There is no support for group templates on consumers;
  • There is no support for custom extensions;

The implementation requires the backend to support a number of new operations. Currently, the following backends have been modified to support catalog zones:

Configuration options

None really.

Per zone settings

It is highly recommended to protect catalog zones with TSIG

CATALOG-HASH

Producer zones store the member state as a hash in this metadata setting. This setting is managed by the authoritative server. Modifying or deleting this value will result in a serial increase of the producer zone and the update or recreation of this value.

Setting up catalog zones

Note

Catalog zone specification and operation is described in RFC 9432.

Setting up a producer zone

Setting up a producer zone is not very different from a regular primary zone. A producer zone is a minimal zone of type PRODUCER with only SOA and NS records at apex. All the records in a producer zone are ignored while generating a catalog.

An initial producer zone may look like this:

$TTL 3600
$ORIGIN catalog.example.
@               IN      SOA     invalid. hostmaster.invalid. (
                        1     ; serial
                        1H    ; refresh
                        10M   ; retry
                        1W    ; expire
                        1800  ; negTTL
                        )

@               IN      NS      invalid.

An interesting detail is the SOA serial: since the serial of a producer zone is automatically updated, it is important for the initial serial to be equal or lower than epoch. This serial is increased to EPOCH after each relevant member update.

Create a producer zone:

pdnsutil load-zone catalog.example ZONEFILE
pdnsutil set-kind catalog.example producer

Creating producer zones is supported in the API, using type PRODUCER.

Assigning members to a producer zone

After the producer zone is created it is necessary to assign member zones to it. In the example below example.com is the member and catalog.example is the catalog.

pdnsutil set-catalog example.com catalog.example
pdnsutil set-kind example.com primary

Setting catalog values is supported in the API, by setting the catalog property in the zone properties. Setting the catalog to an empty "" removes the member zone from the catalog it is in.

Each member zone may have one or more additional properties as defined in the RFC. PowerDNS currently supports the following properties:

  • coo - A single DNSName
  • group - Multiple string values for group are allowed
pdnsutil set-option example.com producer coo other-catalog.example
pdnsutil set-option example.com producer group pdns-group-x pdns-group-y

There is also an option to set a specific <unique-N> value for a zone. This is done by setting a the unique value. This is used to signal a state reset to the consumer. The value for unique is a single DNS label.

pdnsutil --config-dir=. --config-name=gmysql set-option test.com producer unique 123

Setting options is not yet supported in the API.

Setting up a consumer zone

Setting up a consumer zone on a secondary server is almost identical to a normal secondary zone. The only difference is the type, which is now set to CONSUMER.

pdnsutil create-secondary-zone catalog.example 192.0.2.42
pdnsutil set-kind catalog.example consumer

Creating consumer zones is supported in the API, using type CONSUMER.

New member zones on the consumer adopt their primaries from the consumer zone.

Updating a secondary server when primary address/port changes

If NOTIFY+AXFR are being used to replicate zone changes between the primary and secondary servers, and the address and/or port of the primary server changes, two steps are necessary on each secondary server in order to fully apply the changes.

pdnsutil change-secondary-zone-primary catalog.example 192.0.2.45
pdns_control retrieve catalog.example

This will update the primary server contact details in each zone included in the catalog zone.