Add new config

config2/global_ips.go

@@ -0,0 +1,79 @@
+package config2
+
+import (
+	"context"
+	"io"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/juju/errors"
+	"go.uber.org/zap"
+)
+
+const (
+	ifconfigAddress = "https://ifconfig.co/ip"
+	ifconfigTimeout = 10 * time.Second
+)
+
+func getGlobalIPv4(ctx context.Context, cancel context.CancelFunc) {
+	ip, err := fetchIP(ctx, "tcp4")
+	if err != nil || ip.To4() == nil {
+		cancel()
+		zap.S().Errorw("Cannot find public ipv4 address", "error", err)
+		return
+	}
+	C.PublicIPv4Addr.IP = ip
+}
+
+func getGlobalIPv6(ctx context.Context, cancel context.CancelFunc) {
+	ip, err := fetchIP(ctx, "tcp6")
+	if err != nil || ip.To4() != nil {
+		cancel()
+		zap.S().Errorw("Cannot find public ipv6 address", "error", err)
+		return
+	}
+	C.PublicIPv6Addr.IP = ip
+}
+
+func fetchIP(ctx context.Context, network string) (net.IP, error) {
+	dialer := &net.Dialer{FallbackDelay: -1}
+	client := &http.Client{
+		Jar:     nil,
+		Timeout: ifconfigTimeout,
+		Transport: &http.Transport{
+			DialContext: func(ctx context.Context, _, addr string) (net.Conn, error) {
+				return dialer.DialContext(ctx, network, addr)
+			},
+		},
+	}
+
+	req, err := http.NewRequest("GET", ifconfigAddress, nil)
+	if err != nil {
+		panic(err)
+	}
+
+	resp, err := client.Do(req.WithContext(ctx))
+	if err != nil {
+		if resp.Body != nil {
+			io.Copy(ioutil.Discard, resp.Body) // nolint: errcheck
+		}
+		return nil, errors.Annotate(err, "Cannot perform a request")
+	}
+	defer resp.Body.Close() // nolint: errcheck
+
+	respDataBytes, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, errors.Annotate(err, "Cannot read response body")
+	}
+	respData := strings.TrimSpace(string(respDataBytes))
+
+	ip := net.ParseIP(respData)
+	if ip == nil {
+		return nil, errors.Errorf("ifconfig.co returns incorrect IP %s", respData)
+	}
+
+	return ip, nil
+}