make CoreDNS DoH Server (#1619)

* WIP: make CoreDNS DoH Server

* It works

* Fix tests

* Review from Tom - on diff. PR

* correct mime type

* Cleanups and use the pkg/nonwriter

* rename and updates

* implement get

* implement GET

* Code review comments

* correct context

* tweaks

* code review

1 files changed, 12 insertions, 1 deletions

diff --git a/plugin/pkg/nonwriter/nonwriter.go b/plugin/pkg/nonwriter/nonwriter.go
index 7819a320f..b157e4242 100644
--- a/plugin/pkg/nonwriter/nonwriter.go
+++ b/plugin/pkg/nonwriter/nonwriter.go
@@ -2,6 +2,8 @@
 package nonwriter
 
 import (
+	"net"
+
 	"github.com/miekg/dns"
 )
 
@@ -9,6 +11,11 @@ import (
 type Writer struct {
 	dns.ResponseWriter
 	Msg *dns.Msg
+
+	// Raddr is the remote's address. This can be optionally set.
+	Raddr net.Addr
+	// Laddr is our address. This can be optionally set.
+	Laddr net.Addr
 }
 
 // New makes and returns a new NonWriter.
@@ -20,4 +27,8 @@ func (w *Writer) WriteMsg(res *dns.Msg) error {
 	return nil
 }
 
-func (w *Writer) Write(buf []byte) (int, error) { return len(buf), nil }
+// RemoteAddr returns the remote address.
+func (w *Writer) RemoteAddr() net.Addr { return w.Raddr }
+
+// LocalAddr returns the local address.
+func (w *Writer) LocalAddr() net.Addr { return w.Laddr }