DNS resolver is optional

[ojhaujjwal]

Because I have IP Address and I don't want to resolve IP.
But, this will mean that the react/dns is optional and we may remove it from composer.json too.

[WyriHaximus]

Yes please! 👍

[cboden]

I'm +1 for not having to set a Resolver if you're going to use an IP address. However I think I would prefer if that used a Null object pattern that returned the IP address when resolver->resolve() is called instead of throwing an exception. This alteration would prevent a BC break as well.

[edhelas]

I'd really like to see this PR merged.
Actually I'm still using 8.8.8.8 as an hardcoded DNS server in my project (https://github.com/edhelas/movim/blob/master/linker.php#L15) and I see this as a big privacy issue. Is it possible to use the "default" PHP DNS or the one that is set by the OS ? Or maybe I didn't understand something here :) ?

[clue]

👍 on the feature, but 👎 on the implementation as it stands

The suggested API means the Connector is now stateful and it introduces additional runtime complexity. Also, the current implementation throws an Exception instead of rejecting (though this could easily be fixed).

See #46 for an alternative implementation as discussed in #12

Is it possible to use the "default" PHP DNS or the one that is set by the OS ? Or maybe I didn't understand something here :) ?

This is unrelated to this changeset in fact :) Quite surprisingly this hasn't been tracked before, so I've just filed reactphp/dns#29.