fix: update lego.

vendor/github.com/Azure/go-autorest/autorest/sender.go

@@ -1,5 +1,19 @@
 package autorest
 
+// Copyright 2017 Microsoft Corporation
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+
 import (
 	"fmt"
 	"log"
@@ -72,7 +86,7 @@ func SendWithSender(s Sender, r *http.Request, decorators ...SendDecorator) (*ht
 func AfterDelay(d time.Duration) SendDecorator {
 	return func(s Sender) Sender {
 		return SenderFunc(func(r *http.Request) (*http.Response, error) {
-			if !DelayForBackoff(d, 0, r.Cancel) {
+			if !DelayForBackoff(d, 0, r.Context().Done()) {
 				return nil, fmt.Errorf("autorest: AfterDelay canceled before full delay")
 			}
 			return s.Do(r)
@@ -151,7 +165,7 @@ func DoPollForStatusCodes(duration time.Duration, delay time.Duration, codes ...
 			resp, err = s.Do(r)
 
 			if err == nil && ResponseHasStatusCode(resp, codes...) {
-				r, err = NewPollingRequest(resp, r.Cancel)
+				r, err = NewPollingRequestWithContext(r.Context(), resp)
 
 				for err == nil && ResponseHasStatusCode(resp, codes...) {
 					Respond(resp,
@@ -184,7 +198,9 @@ func DoRetryForAttempts(attempts int, backoff time.Duration) SendDecorator {
 				if err == nil {
 					return resp, err
 				}
-				DelayForBackoff(backoff, attempt, r.Cancel)
+				if !DelayForBackoff(backoff, attempt, r.Context().Done()) {
+					return nil, r.Context().Err()
+				}
 			}
 			return resp, err
 		})
@@ -201,18 +217,25 @@ func DoRetryForStatusCodes(attempts int, backoff time.Duration, codes ...int) Se
 			rr := NewRetriableRequest(r)
 			// Increment to add the first call (attempts denotes number of retries)
 			attempts++
-			for attempt := 0; attempt < attempts; attempt++ {
+			for attempt := 0; attempt < attempts; {
 				err = rr.Prepare()
 				if err != nil {
 					return resp, err
 				}
 				resp, err = s.Do(rr.Request())
-				if err != nil || !ResponseHasStatusCode(resp, codes...) {
+				// we want to retry if err is not nil (e.g. transient network failure).  note that for failed authentication
+				// resp and err will both have a value, so in this case we don't want to retry as it will never succeed.
+				if err == nil && !ResponseHasStatusCode(resp, codes...) || IsTokenRefreshError(err) {
 					return resp, err
 				}
-				delayed := DelayWithRetryAfter(resp, r.Cancel)
-				if !delayed {
-					DelayForBackoff(backoff, attempt, r.Cancel)
+				delayed := DelayWithRetryAfter(resp, r.Context().Done())
+				if !delayed && !DelayForBackoff(backoff, attempt, r.Context().Done()) {
+					return nil, r.Context().Err()
+				}
+				// don't count a 429 against the number of attempts
+				// so that we continue to retry until it succeeds
+				if resp == nil || resp.StatusCode != http.StatusTooManyRequests {
+					attempt++
 				}
 			}
 			return resp, err
@@ -223,6 +246,9 @@ func DoRetryForStatusCodes(attempts int, backoff time.Duration, codes ...int) Se
 // DelayWithRetryAfter invokes time.After for the duration specified in the "Retry-After" header in
 // responses with status code 429
 func DelayWithRetryAfter(resp *http.Response, cancel <-chan struct{}) bool {
+	if resp == nil {
+		return false
+	}
 	retryAfter, _ := strconv.Atoi(resp.Header.Get("Retry-After"))
 	if resp.StatusCode == http.StatusTooManyRequests && retryAfter > 0 {
 		select {
@@ -253,7 +279,9 @@ func DoRetryForDuration(d time.Duration, backoff time.Duration) SendDecorator {
 				if err == nil {
 					return resp, err
 				}
-				DelayForBackoff(backoff, attempt, r.Cancel)
+				if !DelayForBackoff(backoff, attempt, r.Context().Done()) {
+					return nil, r.Context().Err()
+				}
 			}
 			return resp, err
 		})