Add UDP source IP into golang dialer https connection for Edgeview

- have seen on certain EVE devices, even walk through various ports, the
  UDP source IP address used stuck on one particular IP address, and it
  then failed on DNS query and failed Edgeview connection.

Signed-off-by: Naiming Shen <naiming@zededa.com>

pkg/edgeview/src/websocket.go

@@ -5,6 +5,7 @@ package main
 
 import (
 	"bytes"
+	"context"
 	"crypto/tls"
 	"crypto/x509"
 	"encoding/json"
@@ -175,7 +176,21 @@ func tlsDial(isServer bool, pIP string, pport int, src []net.IP, idx int) (*webs
 		dialer.Proxy = http.ProxyURL(proxyURL)
 	}
 	if idx >= 0 && len(src) > 0 && idx < len(src) {
-		dialer.NetDialContext = (&net.Dialer{LocalAddr: &net.TCPAddr{IP: src[idx]}}).DialContext
+		srcSelected := src[idx]
+		localAddr := &net.TCPAddr{IP: srcSelected}
+		netDialer := &net.Dialer{
+			LocalAddr: localAddr,
+			Resolver: &net.Resolver{
+				PreferGo: true,
+				Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
+					d := net.Dialer{
+						LocalAddr: &net.UDPAddr{IP: srcSelected},
+					}
+					return d.DialContext(ctx, network, address)
+				},
+			},
+		}
+		dialer.NetDialContext = netDialer.DialContext
 	}
 
 	return dialer, nil