如何为网络程序包设置DNS缓存？

Question

In the "net/http" package I can cache the DNS lookups by:

client := &http.Client{
        Transport: &http.Transport{
            Dial: (&nett.Dialer{
                Resolver: &nett.CacheResolver{TTL: 5 * time.Minute},
                IPFilter: nett.DualStack,
            }).Dial,
        },

    }

then use client to retrieve websites. How do I cache the DNS lookups for the net package? for instance, a reverse DNS request:

net.LookupAddr(ip)

Since this does not use a variable I am confused as to how to get it setup and how to even know if I am using a cached instance.

Answer 1

The nett package seems to just have a single "Resolve" method rather than LookupAddr, LookupIP etc etc that the official net package has. So reverse lookups don't seem to be available. Here's how to do a normal lookup of address from name

package main

import (
    "github.com/abursavich/nett"
    "time"
)

func main() {
    r := nett.CacheResolver{TTL: 5 * time.Minute}
    a, _ := r.Resolve("muppet.com")
    for _, i := range a {
        print(i.String())
    }
}