client-go/rest: backoff with context support

The BackoffManager interface sleeps without considering the caller's context,
i.e. cancellation is not supported. This alone is reason enough to deprecate it
and to replace it with an interface that supports a context parameter.

The other reason is that contextual logging needs that parameter.

Author: pohly

staging/src/k8s.io/apiextensions-apiserver/go.sum

@@ -58,6 +58,7 @@ require (
 	github.com/onsi/ginkgo/v2 v2.21.0 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/objx v0.5.2 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
 	golang.org/x/sys v0.28.0 // indirect
 	golang.org/x/text v0.21.0 // indirect

staging/src/k8s.io/apiserver/go.sum

@@ -0,0 +1,10 @@
+---
+dir: .
+filename: "mock_{{.InterfaceName | snakecase}}_test.go"
+boilerplate-file: ../../../../../hack/boilerplate/boilerplate.generatego.txt
+outpkg: rest
+with-expecter: true
+packages:
+  k8s.io/client-go/rest:
+    interfaces:
+      BackoffManager:

staging/src/k8s.io/client-go/go.mod

@@ -93,7 +93,7 @@ type RESTClient struct {
 	content requestClientContentConfigProvider
 
 	// creates BackoffManager that is passed to requests.
-	createBackoffMgr func() BackoffManager
+	createBackoffMgr func() BackoffManagerWithContext
 
 	// rateLimiter is shared among all requests created by this client unless specifically
 	// overridden.
@@ -178,7 +178,7 @@ func (c *RESTClient) GetRateLimiter() flowcontrol.RateLimiter {
 // readExpBackoffConfig handles the internal logic of determining what the
 // backoff policy is.  By default if no information is available, NoBackoff.
 // TODO Generalize this see #17727 .
-func readExpBackoffConfig() BackoffManager {
+func readExpBackoffConfig() BackoffManagerWithContext {
 	backoffBase := os.Getenv(envBackoffBase)
 	backoffDuration := os.Getenv(envBackoffDuration)
 

staging/src/k8s.io/client-go/go.sum

@@ -35,6 +35,7 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/client-go/kubernetes/scheme"
 	utiltesting "k8s.io/client-go/util/testing"
+	"k8s.io/klog/v2/ktesting"
 
 	"github.com/google/go-cmp/cmp"
 )
@@ -335,36 +336,36 @@ func TestHTTPProxy(t *testing.T) {
 }
 
 func TestCreateBackoffManager(t *testing.T) {
-
+	_, ctx := ktesting.NewTestContext(t)
 	theUrl, _ := url.Parse("http://localhost")
 
 	// 1 second base backoff + duration of 2 seconds -> exponential backoff for requests.
 	t.Setenv(envBackoffBase, "1")
 	t.Setenv(envBackoffDuration, "2")
 	backoff := readExpBackoffConfig()
-	backoff.UpdateBackoff(theUrl, nil, 500)
-	backoff.UpdateBackoff(theUrl, nil, 500)
-	if backoff.CalculateBackoff(theUrl)/time.Second != 2 {
+	backoff.UpdateBackoffWithContext(ctx, theUrl, nil, 500)
+	backoff.UpdateBackoffWithContext(ctx, theUrl, nil, 500)
+	if backoff.CalculateBackoffWithContext(ctx, theUrl)/time.Second != 2 {
 		t.Errorf("Backoff env not working.")
 	}
 
 	// 0 duration -> no backoff.
 	t.Setenv(envBackoffBase, "1")
 	t.Setenv(envBackoffDuration, "0")
-	backoff.UpdateBackoff(theUrl, nil, 500)
-	backoff.UpdateBackoff(theUrl, nil, 500)
+	backoff.UpdateBackoffWithContext(ctx, theUrl, nil, 500)
+	backoff.UpdateBackoffWithContext(ctx, theUrl, nil, 500)
 	backoff = readExpBackoffConfig()
-	if backoff.CalculateBackoff(theUrl)/time.Second != 0 {
+	if backoff.CalculateBackoffWithContext(ctx, theUrl)/time.Second != 0 {
 		t.Errorf("Zero backoff duration, but backoff still occurring.")
 	}
 
 	// No env -> No backoff.
 	t.Setenv(envBackoffBase, "")
 	t.Setenv(envBackoffDuration, "")
 	backoff = readExpBackoffConfig()
-	backoff.UpdateBackoff(theUrl, nil, 500)
-	backoff.UpdateBackoff(theUrl, nil, 500)
-	if backoff.CalculateBackoff(theUrl)/time.Second != 0 {
+	backoff.UpdateBackoffWithContext(ctx, theUrl, nil, 500)
+	backoff.UpdateBackoffWithContext(ctx, theUrl, nil, 500)
+	if backoff.CalculateBackoffWithContext(ctx, theUrl)/time.Second != 0 {
 		t.Errorf("Backoff should have been 0.")
 	}
 

staging/src/k8s.io/client-go/rest/.mockery.yaml

@@ -106,7 +106,7 @@ type Request struct {
 	warningHandler WarningHandlerWithContext
 
 	rateLimiter flowcontrol.RateLimiter
-	backoff     BackoffManager
+	backoff     BackoffManagerWithContext
 	timeout     time.Duration
 	maxRetries  int
 
@@ -136,7 +136,7 @@ type Request struct {
 
 // NewRequest creates a new request helper object for accessing runtime.Objects on a server.
 func NewRequest(c *RESTClient) *Request {
-	var backoff BackoffManager
+	var backoff BackoffManagerWithContext
 	if c.createBackoffMgr != nil {
 		backoff = c.createBackoffMgr()
 	}
@@ -259,13 +259,27 @@ func (r *Request) Resource(resource string) *Request {
 }
 
 // BackOff sets the request's backoff manager to the one specified,
-// or defaults to the stub implementation if nil is provided
+// or defaults to the stub implementation if nil is provided.
+//
+// Deprecated: BackoffManager.Sleep ignores the caller's context. Use BackOffWithContext and BackoffManagerWithContext instead.
 func (r *Request) BackOff(manager BackoffManager) *Request {
 	if manager == nil {
 		r.backoff = &NoBackoff{}
 		return r
 	}
 
+	r.backoff = &backoffManagerNopContext{BackoffManager: manager}
+	return r
+}
+
+// BackOffWithContext sets the request's backoff manager to the one specified,
+// or defaults to the stub implementation if nil is provided.
+func (r *Request) BackOffWithContext(manager BackoffManagerWithContext) *Request {
+	if manager == nil {
+		r.backoff = &NoBackoff{}
+		return r
+	}
+
 	r.backoff = manager
 	return r
 }