updates to use net/http/httpproxy

agent/httpclient/httpclient.go

@@ -23,6 +23,7 @@ import (
 	"time"
 
 	"github.com/aws/amazon-ecs-agent/agent/config"
+	"github.com/aws/amazon-ecs-agent/agent/utils"
 	"github.com/aws/amazon-ecs-agent/agent/utils/cipher"
 	"github.com/aws/amazon-ecs-agent/agent/version"
 )
@@ -59,7 +60,7 @@ func New(timeout time.Duration, insecureSkipVerify bool) *http.Client {
 	// Note, these defaults are taken from the golang http library. We do not
 	// explicitly do not use theirs to avoid changing their behavior.
 	transport := &http.Transport{
-		Proxy: http.ProxyFromEnvironment,
+		Proxy: utils.Proxy,
 		Dial: (&net.Dialer{
 			Timeout:   defaultDialTimeout,
 			KeepAlive: defaultDialKeepalive,

agent/utils/utils.go

@@ -21,6 +21,8 @@ import (
 	"io/ioutil"
 	"math"
 	"math/big"
+	"net/http"
+	"net/url"
 	"path/filepath"
 	"reflect"
 	"strconv"
@@ -32,6 +34,7 @@ import (
 	"github.com/aws/aws-sdk-go/aws/awserr"
 
 	"github.com/pkg/errors"
+	"golang.org/x/net/http/httpproxy"
 )
 
 func DefaultIfBlank(str string, default_value string) string {
@@ -234,3 +237,8 @@ func GetENIAttachmentId(eniAttachmentArn string) (string, error) {
 	}
 	return fields[len(fields)-1], nil
 }
+
+// Proxy is an uncached version of http.ProxyFromEnvironment.
+func Proxy(req *http.Request) (*url.URL, error) {
+	return httpproxy.FromEnvironment().ProxyFunc()(req.URL)
+}