fix proxy support (danielpaulus#448)

In Golang only the default http client uses the system wide env var. this led to some weird behavior with half
of go-ios supporting it and the other half not so much. I changed it to use the default transport always.

Author: danielpaulus

ios/imagemounter/imagedownloader.go

@@ -9,6 +9,7 @@ import (
 	"path/filepath"
 	"runtime"
 	"strings"
+	"time"
 
 	"github.com/Masterminds/semver"
 	"github.com/danielpaulus/go-ios/ios"
@@ -247,8 +248,12 @@ func validateBaseDirAndLookForImage(baseDir string, imageToFind string) (string,
 // write as it downloads and not load the whole file into memory.
 // PS: Taken from golangcode.com
 func downloadFile(filepath string, url string) error {
+	c := &http.Client{
+		Timeout:   2 * time.Minute,
+		Transport: http.DefaultTransport,
+	}
 	// Get the data
-	resp, err := http.Get(url)
+	resp, err := c.Get(url)
 	if err != nil {
 		return err
 	}

ios/imagemounter/tss.go

@@ -20,7 +20,8 @@ type tssClient struct {
 
 func newTssClient() tssClient {
 	c := &http.Client{
-		Timeout: 1 * time.Minute,
+		Timeout:   1 * time.Minute,
+		Transport: http.DefaultTransport,
 	}
 
 	return tssClient{

ios/mobileactivation/albert.go

@@ -15,7 +15,8 @@ const (
 )
 
 var netClient = &http.Client{
-	Timeout: time.Second * 5,
+	Timeout:   time.Second * 5,
+	Transport: http.DefaultTransport,
 }
 
 func sendHandshakeRequest(body io.Reader) (http.Header, io.ReadCloser, error) {

main.go

@@ -7,6 +7,8 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"net/http"
+	"net/url"
 	"os"
 	"os/signal"
 	"path"
@@ -145,6 +147,8 @@ Options:
   >                         connect a device and open Xcode
   --rsd-port=<port>         Port of remote service discovery on the device through the tunnel
   >                         This parameter is similar to '--address' and can be obtained by the same log filter
+  --proxyurl=<url>          Set this if you want go-ios to use a http proxy for outgoing requests, like for downloading images or contacting Apple during device activation.
+  >                         A simple format like: "http://PROXY_LOGIN:PROXY_PASS@proxyIp:proxyPort" works. Otherwise use the HTTP_PROXY system env var.
 
 The commands work as following:
 	The default output of all commands is JSON. Should you prefer human readable outout, specify the --nojson option with your command.
@@ -291,6 +295,15 @@ The commands work as following:
 		printVersion()
 		return
 	}
+	proxyUrl, _ := arguments.String("--proxyurl")
+	if proxyUrl == "" {
+		proxyUrl = os.Getenv("HTTP_PROXY")
+	}
+	if proxyUrl != "" {
+		parsedUrl, err := url.Parse(proxyUrl)
+		exitIfError("failed parsing proxy url", err)
+		http.DefaultTransport = &http.Transport{Proxy: http.ProxyURL(parsedUrl)}
+	}
 
 	b, _ := arguments.Bool("listen")
 	if b {
@@ -1115,6 +1128,7 @@ func imageCommand1(device ios.DeviceEntry, arguments docopt.Opts) bool {
 			if err != nil {
 				log.WithFields(log.Fields{"basedir": basedir, "udid": device.Properties.SerialNumber, "err": err}).
 					Error("failed downloading image")
+				return false
 			}
 
 			log.WithFields(log.Fields{"basedir": basedir, "udid": device.Properties.SerialNumber}).Info("success downloaded image")