add ipv6 listening for API / WebGateway

[RubenKelevra]

No description provided.

[welcome]

Thank you for submitting this PR!
A maintainer will be here shortly to review it.
We are super grateful, but we are also overloaded! Help us by making sure that:

• The context for this PR is clear, with relevant discussion, decisions
  and stakeholders linked/mentioned.

• Your contribution itself is clear (code comments, self-review for the
  rest) and in its best form. Follow the code contribution
  guidelines
  if they apply.

Getting other community members to do a review would be great help too on complex PRs (you can ask in the chats/forums). If you are unsure about something, just leave us a comment.
Next steps:

• A maintainer will triage and assign priority to this PR, commenting on
  any missing things and potentially assigning a reviewer for high
  priority items.

• The PR gets reviews, discussed and approvals as needed.

• The PR is merged by maintainers when it has been approved and comments addressed.

We currently aim to provide initial feedback/triaging within two business days. Please keep an eye on any labelling actions, as these will indicate priorities and status of your contribution.
We are very grateful for your contribution!

[rpodgorny]

thumbs up for ipv6!

[Stebalien]

Why are you changing these types?

[RubenKelevra]

Well, Swarm, Announce and NoAnnounce are arrays, because they hold multiple addresses.

API and Gateway now need to hold multiple addresses too. So they need to be an array.

Or is there's something wrong with my assumption?

[Stebalien]

We created the Strings type to allow either a single string or an array of strings. Changing this to a simple array would be a backwards incompatible change.

[Stebalien]

What's the motivation for listening on IPv6 for localhost? IPv4 should always work for localhost regardless.

[rpodgorny]

What's the motivation for listening on IPv6 for localhost? IPv4 should always work for localhost regardless.

...because [::1] is shorter to type than 127.0.0.1? ;-)

now, kidding aside, ipv6 simply supersedes ipv4 and will be the the default protocol in the future. actually, it could be the default right now if people cared a bit more. ...imagine the feeling when you're dropping all this nat-traversing code and shit! ;-)

i agree the localhost is the least case where ipv6 is important but i look at it from a different point of view. i feel this as a part of the "ipv6 by default everywhere" mindset that will drag the general ipv6 adoption with it...

anyway, at least for this very patch, i don't see any negative (increased code complexity, security issues, ...) with it so in my opinion it should be a "go" even if you personally don't really care about ipv6 that much.

[Stebalien]

Fair enough. I'm just always wary of changes without reasons because https://xkcd.com/1172/.

[RubenKelevra]

What's the motivation for listening on IPv6 for localhost? IPv4 should always work for localhost regardless.

Well, there's no reason why we shouldn't use IPv6. I dislike using legacy IP. :)

[RubenKelevra]

Sorry, messed that up. I'm not sure you can change the remote branch of a PR, so I filed a new one.