coredns/middleware/httpproxy/proxy.go
Miek Gieben 96222927a3 middleware/httpproxy: Add (#439)
This PR adds a middleware that talks to dns.google.com over HTTPS,
meaning all your DNS traffic is encrypted when traversing your ISP and
the internet.

The `dns.google.com` address is re-resolved every 30 seconds.
2016-11-26 17:57:22 +00:00

45 lines
1.1 KiB
Go

// Package httpproxy is middleware that proxies requests to a HTTPs server doing DNS.
package httpproxy
import (
"errors"
"time"
"github.com/miekg/coredns/middleware"
"github.com/miekg/coredns/request"
"github.com/miekg/dns"
"golang.org/x/net/context"
)
var errUnreachable = errors.New("unreachable backend")
// Proxy represents a middleware instance that can proxy requests to HTTPS servers.
type Proxy struct {
from string
e Exchanger
Next middleware.Handler
}
// ServeDNS satisfies the middleware.Handler interface.
func (p *Proxy) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
start := time.Now()
state := request.Request{W: w, Req: r}
reply, backendErr := p.e.Exchange(r)
if backendErr == nil {
state.SizeAndDo(reply)
w.WriteMsg(reply)
RequestDuration.WithLabelValues(p.from).Observe(float64(time.Since(start) / time.Millisecond))
return 0, nil
}
RequestDuration.WithLabelValues(p.from).Observe(float64(time.Since(start) / time.Millisecond))
return dns.RcodeServerFailure, errUnreachable
}
// Name implements the Handler interface.
func (p Proxy) Name() string { return "httpproxy" }