gopcap VS dns

Among the many early review articles of pre-1.0 Go, a common criticism was the lack of generics, or parameterized types. Having used Go for my personal projects since late 2009 and professionally since 2013, I kind of understood the criticism because it was the kind of feature that you would naturally expect in a new language as other modern languages of the time would often feature generics in some shape or form. C++ went to the extreme with it, as its template system goes beyond just type parameterization and was even found to be Turing-complete. Practically though, in the several years of actively using Go pretty much every work day, writing many tens of thousands of line of code, I've only ever come across one situation where I thought that parameterized types would have been really handy and would have made it so much easier to write less repetitive code.

The heavylifting is done by this package: https://github.com/miekg/dns.

Apart from `dig`, clients like https://github.com/miekg/dns show the same behavior.

For the DNS i wrote a PiHole clone, which on the core it uses github.com/miekg/dns, to upstream queries and also to handle the custom entries, i've been wanting to publish that project but haven't done so cause the code is a bit messy since i did it as a PoC mostly, when comparing it to pihole it has the advantage that its really resource light mostly on the admin features, the dns resolving performs pretty much the same.

coredns uses github.com/miekg/dns under the hood

You can do the same with net.Resolver, either by just setting it's Dial function (and PreferGo=true). You can use https://pkg.go.dev/golang.org/x/net/dns/dnsmessage or https://github.com/miekg/dns to implement an in-process server, either over TCP/UDP or skipping real networking completely, just like you can do with https://golang.org/pkg/net/http/httptest

Had a similar problem a couple years ago where I needed to use alternative DNS libraries to troubleshoot issues in a company's infrastructure.

Golang's rules for what implementation to use are found here: https://golang.org/pkg/net/#hdr-Name_Resolution

A really solid alternative DNS client implementation can be found here: https://github.com/miekg/dns. Real easy to read and vet compared to a few other libraries I ran into when working on this problem.