optional ipv6 for repo

[ericsullivan]

Changes

I tried to self-host on fly.io, but it uses IPv6 for DB access:
https://hexdocs.pm/phoenix/fly.html#runtime-configuration

This changes follows the current Phoenix generator setup:
https://github.com/phoenixframework/phoenix/blob/master/installer/lib/phx_new/generator.ex#L355

It had been defaulted to inet6:
phoenixframework/phoenix#4289

but that caused an issue:
phoenixframework/phoenix#4389

Tests

• This PR does not require tests

Changelog

• Entry has been added to changelog

Documentation

• Docs have been updated
• This change does not need a documentation update

Dark mode

• The UI has been tested both in dark and light mode
• This PR does not change the UI

[ukutaht]

Thanks! Definitely interested in getting this in.

Did you consider parsing the DATABASE_URL config parameter? So if the hostname is an IPv6 then the [:inet6]config option will automatically be applied. I don't understand why Ecto doesn't work that way to begin with

[ericsullivan]

@ukutaht The DATABASE_URL uses a DNS entry like:

DATABASE_URL=postgres://<USERNAME>:<PW>@top2.nearest.of.plausible-db.internal:5432/plausible

So you can't tell it's an IPv6 without doing the lookup. Since it's fly.io they're all IPv6, which is why I used the ENV approach

[ukutaht]

Oh, gotcha. That makes sense.

[ericsullivan]

Thank you