CLI for adding/removing non-container DNS records

[rade]

The weaveDNS API permits the addition/removal of records that are not associated with containers. But this functionality is not available in the CLI - weave dns-add|remove require a container name/id.

We should remove that restriction. Quite how to express that in the CLI is tbd.

This has been requested by a user.

[inercia]

Would this mean that users could be able to add arbitrary A-records in the distributed database?

[rade]

Would this mean that users could be able to add arbitrary A-records in the distributed database?

No, only records in the weavedns domain. I am hoping(!) that is what the current weave dns-add enforces.

[inercia]

But that wouldn't be a good idea once we have the gossip-dns in the production release, right? I mean that populating the distributed database with entries like srv-<SOME-NUMBER>.weave.local. = <SOME-IP> wouldn't be the ideal scenario for gossiping...

[rade]

What's the issue?

I can see one fundamental problem: weavedns entries are necessarily associated with a peer, and when that peer disappears the entries too disappear.

Is that the problem you were forseeing?

[inercia]

My concern is that, if the distributed database becomes a general DNS database where a user could introduce thoushands of A-records (even if they are in the weavedns domain), it would potentially increase latency to the database propagation...

[tomwilkie]

There is no performance problems associated with this; individual records
are gossiped when they are added and removed, the whole databases is only
gossiped periodically.

Matthias does point out an issue though; records are owned by a host and
their failure domains are assumed to align. I'll give a little thought to
what might happen if a record is not owned by a host; I suspect 'all' we'd
need to do is increase the tombstone timeout on those records.

On Friday, 4 September 2015, Alvaro notifications@github.com wrote:

My concern is that, if the distributed database becomes a general DNS
database where a user could introduce thoushands of A-records (even if they
are in the weavedns domain), it would potentially increase latency to the
database propagation...

—
Reply to this email directly or view it on GitHub
#1385 (comment).

[dpw]

There is a substitute suggested by @errordeveloper a few days ago. Although you have to supply a container name to dns-add, you can supply any container name, including e.g. weave for the weave router container. So:

weave dns-add 8.8.8.8 weave -h foo.weave.local

works.

That name will be lost if the weave router is stopped, but that would also be the case for the simple fix to address this issue anyway.