Adding a secondary name server for a domain in MAAS

The question came up “how do I add an authoritative (secondary) name server for a domain that is managed by MAAS?”

Why would I want to do that?

There are various reasons, including that the region controller may just be busy enough, or the MAAS region spread out enough, that we don’t want to have all DNS go through it.  Another reason would be to avoid exposing the region controller to the internet, while still allowing it to provide authoritative DNS data for machines inside the region.

How do I do that?

First, we’ll need to create a secondary nameserver.  For purposes of simplicity, we’ll assume that it’s an Ubuntu machine named mysecondary.example.com, and that you have installed the bind9 package.  And we’ll assume that  you have named the domain maas, that the region controller is named region.example.com, with an upstream interface having the IP address a.b.c.d, and that you have a MAAS session called admin.

On mysecondary.example.com, we add this to /etc/bind/named.conf.local:

zone "maas" { type slave; file "db.maas"; masters { a.b.c.d; }; };

Then reload named there via “rndc reload”

With the MAAS CLI, we then say (note the trailing “.” on rrdata):

maas admin dnsresource-records create name=@ domain=maas rrtype=ns rrdata=mysecondary.example.com.

At that point, mysecondary is both authoritative, and named in the NS RRset for the domain.

What else can I do?

If you call the MAAS domain somename.example.com, then you could add NS records to the example.com DNS zone delegating that zone to the MAAS region and it’s secondaries.

What are the actual limitations?

  • The region controller is always listed as a name server for the domain.  For domains other than the default.  See also bug 1672220 about address records.
  • If MAAS is told that it’s authoritative for a domain, it IS the master/primary.
  • The MAAS region does not have zones that are other than “type master”.

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