doh: set http request in writer (#4445)

Makes it possible to read the current http request while serving DNS

Signed-off-by: Johnny Bergström <johnny@klaudify.se>

core/dnsserver/https.go

@@ -2,6 +2,7 @@ package dnsserver
 
 import (
 	"net"
+	"net/http"
 
 	"github.com/coredns/coredns/plugin/pkg/nonwriter"
 )
@@ -14,6 +15,9 @@ type DoHWriter struct {
 	raddr net.Addr
 	// laddr is our address. This can be optionally set.
 	laddr net.Addr
+
+	// request is the HTTP request we're currently handling.
+	request *http.Request
 }
 
 // RemoteAddr returns the remote address.
@@ -21,3 +25,6 @@ func (d *DoHWriter) RemoteAddr() net.Addr { return d.raddr }
 
 // LocalAddr returns the local address.
 func (d *DoHWriter) LocalAddr() net.Addr { return d.laddr }
+
+// Request returns the HTTP request
+func (d *DoHWriter) Request() *http.Request { return d.request }