Recursive lookup of CNAME value

[gliwka]

Let's suppose I have the following DNS zone:

subdomain.example.com. 3600 IN CNAME cname.example.org
subdomain.example.com. 3600 IN MX mx.example.org

I now want to make a recursive query (starting from the root zone) and lookup the values for MX and CNAME in this zone.

Looking up the MX value using resolveAll() works fine - it returns the MX record containing hostname and priority ("mx.example.org").

Which API can I use to accomplish the same thing for the CNAME value? If I use the resolveAll() API with a CNAME question, it always follows cname.example.org and tries to resolve that instead of returning it.

[trustin]

If I understood correctly, if you try to send a DNS query for CNAME subdomain.example.com, you expect it to return CNAME cname.example.org, right? I guess in that case you can use DnsNameResolver.query() which never follows any redirection.

[gliwka]

This doesn't work for recursive lookups. The authoritative name server for subdomain.example.com is not yet known to me, so I cant query it directly. That's why I'm currently using resolveAll() to benefit from the recursive lookup - this works for all record classes except CNAME. I'm using netty as a recursive resolver.

What do you think about a new resolveAll() method with the option to disable following the CNAME? Would you be willing to accept a PR for this usecase?

[NiteshKant]

What do you think about a new resolveAll() method with the option to disable following the CNAME?

A special method that is a special case to skip CNAME resolve seems less preferable than a generic way to stop resolutions, perhaps at each step. Anyways, happy to review if you have a PR

[trustin]

@gliwka I see. I agree with @NiteshKant on accepting some Predicate that determines when to stop. Thanks for exploring this option. 🙇

[mrniko]

Hello All. Is there any solution for this issue?

[shivam2146]

@NiteshKant / @trustin Any solution/workaround for this issue?