feat: NAT64 network source

[johannwagner]

Description

We run an IPv6 only Kubernetes cluster environment and designated a /96 IPv6 network to map to an IPv4 address space in a casual NAT64 setup. Therefore, we need to create an A record for each AAAA record within this address room.

We added an additional source wrapper, similar to DedupSource and added a config value for the NAT64 prefixes. The source wrapper looks at all AAAA records and translates them - if applicable - into A records.
We also added unit tests for that.

Note: I did not add any enduser documentation, because I was not sure where to put this part specifically. If you can give me a pointer, I would be happy to add this.

Checklist

• Unit tests updated
• End user documentation updated

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: johannwagner / name: Johann Wagner (b8e018c, 1b4843a)

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[johannwagner]

/easycla

[mloiseleur]

It's very interesting, thanks 👍.
For the documentation, there is a source tab, see here. Wdyt of adding a new doc in this section ?
/ok-to-test

[johannwagner]

Thanks!

I will add docs on Monday, currently on vacation. 🙌

[johannwagner]

Since it is not really a source-based addition and should work for all sources, I would rather put it in the Advanced Topic section after some consideration.

[johannwagner]

Added some documentation, I also tried to give a usage example but it's very networky and probably a niece topic anyways.

[mloiseleur]

/retitle feat: NAT64 network source
/lgtm

[szuecs]

/approve

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This pull-request has been approved by: szuecs

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