Always retry a request even if the sender returns a non-nil error

CHANGELOG.md

@@ -1,5 +1,11 @@
 # CHANGELOG
 
+## v13.0.2
+
+### Bug Fixes
+
+- Always retry a request even if the sender returns a non-nil error.
+
 ## v13.0.1
 
 ## Bug Fixes
@@ -12,9 +18,9 @@
 
 The `tracing` package has been rewritten to provide a common interface for consumers to wire in the tracing package of their choice.
 What this means is that by default no tracing provider will be compiled into your program and setting the `AZURE_SDK_TRACING_ENABLED`
-environment variable will have no effect.  To enable this previous behavior you must now add the following include to your source file.
+environment variable will have no effect.  To enable this previous behavior you must now add the following import to your source file.
 ```go
-  include _ "github.com/Azure/go-autorest/tracing/opencensus"
+  import _ "github.com/Azure/go-autorest/tracing/opencensus"
 ```
 The APIs required by autorest-generated code have remained but some APIs have been removed and new ones added.
 The following APIs and variables have been removed (the majority of them were moved to the `opencensus` package).

autorest/adal/token.go

@@ -26,7 +26,6 @@ import (
 	"fmt"
 	"io/ioutil"
 	"math"
-	"net"
 	"net/http"
 	"net/url"
 	"strings"
@@ -913,10 +912,8 @@ func retryForIMDS(sender Sender, req *http.Request, maxAttempts int) (resp *http
 
 	for attempt < maxAttempts {
 		resp, err = sender.Do(req)
-		// retry on temporary network errors, e.g. transient network failures.
-		// if we don't receive a response then assume we can't connect to the
-		// endpoint so we're likely not running on an Azure VM so don't retry.
-		if (err != nil && !isTemporaryNetworkError(err)) || resp == nil || resp.StatusCode == http.StatusOK || !containsInt(retries, resp.StatusCode) {
+		// we want to retry if err is not nil or the status code is in the list of retry codes
+		if err == nil && !responseHasStatusCode(resp, retries...) {
 			return
 		}
 
@@ -940,20 +937,12 @@ func retryForIMDS(sender Sender, req *http.Request, maxAttempts int) (resp *http
 	return
 }
 
-// returns true if the specified error is a temporary network error or false if it's not.
-// if the error doesn't implement the net.Error interface the return value is true.
-func isTemporaryNetworkError(err error) bool {
-	if netErr, ok := err.(net.Error); !ok || (ok && netErr.Temporary()) {
-		return true
-	}
-	return false
-}
-
-// returns true if slice ints contains the value n
-func containsInt(ints []int, n int) bool {
-	for _, i := range ints {
-		if i == n {
-			return true
+func responseHasStatusCode(resp *http.Response, codes ...int) bool {
+	if resp != nil {
+		for _, i := range codes {
+			if i == resp.StatusCode {
+				return true
+			}
 		}
 	}
 	return false

autorest/sender.go

@@ -289,10 +289,6 @@ func doRetryForStatusCodesImpl(s Sender, r *http.Request, count429 bool, attempt
 			return
 		}
 		resp, err = s.Do(rr.Request())
-		// if the error isn't temporary don't bother retrying
-		if err != nil && !IsTemporaryNetworkError(err) {
-			return
-		}
 		// 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) {

autorest/sender_test.go

@@ -923,19 +923,20 @@ func (fe fatalError) Temporary() bool {
 }
 
 func TestDoRetryForStatusCodes_NilResponseFatalError(t *testing.T) {
+	const retryAttempts = 3
 	client := mocks.NewSender()
-	client.AppendResponse(nil)
-	client.SetError(fatalError{"fatal error"})
+	client.AppendAndRepeatResponse(nil, retryAttempts+1)
+	client.SetAndRepeatError(fatalError{"fatal error"}, retryAttempts+1)
 
 	r, err := SendWithSender(client, mocks.NewRequest(),
-		DoRetryForStatusCodes(3, time.Duration(1*time.Second), StatusCodesForRetry...),
+		DoRetryForStatusCodes(retryAttempts, time.Duration(1*time.Second), StatusCodesForRetry...),
 	)
 
 	Respond(r,
 		ByDiscardingBody(),
 		ByClosing())
 
-	if err == nil || client.Attempts() > 1 {
+	if err == nil || client.Attempts() < retryAttempts+1 {
 		t.Fatalf("autorest: Sender#TestDoRetryForStatusCodes_NilResponseFatalError -- Got: nil error or wrong number of attempts - %v", err)
 	}
 }

autorest/version.go

@@ -19,7 +19,7 @@ import (
 	"runtime"
 )
 
-const number = "v13.0.1"
+const number = "v13.0.2"
 
 var (
 	userAgent = fmt.Sprintf("Go/%s (%s-%s) go-autorest/%s",