# CoreDNS Chaining Middleware


[CoreDNS](https://github.com/miekg/coredns) is shaping up nicely and of course
the middleware (taken from [Caddy](https://caddyserver.com/)) is working great.

Take for instance the following. We want to rewrite ANY queries to HINFO (because
[DDoS](https://tools.ietf.org/html/draft-dnsop-refuse-any-00)) and *then* proxy them
to Google. We also need some logging. So after downloading and compiling CoreDNS, create
the following `Corefile`:

~~~ txt
.:1053 {
    log stdout
    rewrite ANY HINFO
    proxy . 8.8.8.8:53
}
~~~

By default CoreDNS will read a file called `Corefile`, so we can just start it with:

~~~
% ulimit -n 4096
% ./coredns
Activating privacy features...
.:1053
~~~

Queries work as expected, `dig @localhost -p 1053 mx miek.nl` will work and will show up in the
logs:

~~~
127.0.0.1 - [19/Mar/2016:21:15:22 +0000] "MX miek.nl. udp" NOERROR 170
~~~

But lets try a `ANY` query, `dig @localhost -p 1053 ANY miek.nl`, the reply we get back is:

~~~
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;miek.nl.			IN	ANY

;; AUTHORITY SECTION:
miek.nl.		1799	IN	SOA	linode.atoom.net. miek.miek.nl. 1458360781 14400 3600 604800 14400
~~~

Which is *not* the reply you'd expect from an ANY query, the log makes clear that the rewrite
happened:

~~~
127.0.0.1 - [19/Mar/2016:21:18:17 +0000] "HINFO miek.nl. udp" NOERROR 94
~~~