TUN-1099: Bring back changes in 2018.10.1

cmd/cloudflared/tunnel/server.go

@@ -0,0 +1,33 @@
+package tunnel
+
+import (
+	"github.com/cloudflare/cloudflared/tunneldns"
+
+	"gopkg.in/urfave/cli.v2"
+
+	"github.com/pkg/errors"
+)
+
+func runDNSProxyServer(c *cli.Context, dnsReadySignal, shutdownC chan struct{}) error {
+	port := c.Int("proxy-dns-port")
+	if port <= 0 || port > 65535 {
+		logger.Errorf("The 'proxy-dns-port' must be a valid port number in <1, 65535> range.")
+		return errors.New("The 'proxy-dns-port' must be a valid port number in <1, 65535> range.")
+	}
+	listener, err := tunneldns.CreateListener(c.String("proxy-dns-address"), uint16(port), c.StringSlice("proxy-dns-upstream"))
+	if err != nil {
+		close(dnsReadySignal)
+		listener.Stop()
+		logger.WithError(err).Error("Cannot create the DNS over HTTPS proxy server")
+		return errors.Wrap(err, "Cannot create the DNS over HTTPS proxy server")
+	}
+
+	err = listener.Start(dnsReadySignal)
+	if err != nil {
+		logger.WithError(err).Error("Cannot start the DNS over HTTPS proxy server")
+		return errors.Wrap(err, "Cannot start the DNS over HTTPS proxy server")
+	}
+	<-shutdownC
+	listener.Stop()
+	return nil
+}