update kube and vendor dependencies

With kubernetes 1.18 release of client-go, signatures on methods in
generated clientsets, dynamic, metadata, and scale clients have been
modified to accept context.Context as a first argument.
Signatures of Create, Update, and Patch methods have been updated
to accept CreateOptions, UpdateOptions and PatchOptions respectively.
Signatures of Delete and DeleteCollection methods now accept
DeleteOptions by value instead of by reference.
These changes are now accommodated with this PR and client-go
and dependencies are updated to v1.18.0

Signed-off-by: Humble Chirammal <hchiramm@redhat.com>

vendor/k8s.io/apimachinery/pkg/util/wait/wait.go

@@ -19,10 +19,12 @@ package wait
 import (
 	"context"
 	"errors"
+	"math"
 	"math/rand"
 	"sync"
 	"time"
 
+	"k8s.io/apimachinery/pkg/util/clock"
 	"k8s.io/apimachinery/pkg/util/runtime"
 )
 
@@ -128,9 +130,15 @@ func NonSlidingUntilWithContext(ctx context.Context, f func(context.Context), pe
 // Close stopCh to stop. f may not be invoked if stop channel is already
 // closed. Pass NeverStop to if you don't want it stop.
 func JitterUntil(f func(), period time.Duration, jitterFactor float64, sliding bool, stopCh <-chan struct{}) {
-	var t *time.Timer
-	var sawTimeout bool
+	BackoffUntil(f, NewJitteredBackoffManager(period, jitterFactor, &clock.RealClock{}), sliding, stopCh)
+}
 
+// BackoffUntil loops until stop channel is closed, run f every duration given by BackoffManager.
+//
+// If sliding is true, the period is computed after f runs. If it is false then
+// period includes the runtime for f.
+func BackoffUntil(f func(), backoff BackoffManager, sliding bool, stopCh <-chan struct{}) {
+	var t clock.Timer
 	for {
 		select {
 		case <-stopCh:
@@ -138,13 +146,8 @@ func JitterUntil(f func(), period time.Duration, jitterFactor float64, sliding b
 		default:
 		}
 
-		jitteredPeriod := period
-		if jitterFactor > 0.0 {
-			jitteredPeriod = Jitter(period, jitterFactor)
-		}
-
 		if !sliding {
-			t = resetOrReuseTimer(t, jitteredPeriod, sawTimeout)
+			t = backoff.Backoff()
 		}
 
 		func() {
@@ -153,7 +156,7 @@ func JitterUntil(f func(), period time.Duration, jitterFactor float64, sliding b
 		}()
 
 		if sliding {
-			t = resetOrReuseTimer(t, jitteredPeriod, sawTimeout)
+			t = backoff.Backoff()
 		}
 
 		// NOTE: b/c there is no priority selection in golang
@@ -164,8 +167,7 @@ func JitterUntil(f func(), period time.Duration, jitterFactor float64, sliding b
 		select {
 		case <-stopCh:
 			return
-		case <-t.C:
-			sawTimeout = true
+		case <-t.C():
 		}
 	}
 }
@@ -203,6 +205,12 @@ var ErrWaitTimeout = errors.New("timed out waiting for the condition")
 // if the loop should be aborted.
 type ConditionFunc func() (done bool, err error)
 
+// runConditionWithCrashProtection runs a ConditionFunc with crash protection
+func runConditionWithCrashProtection(condition ConditionFunc) (bool, error) {
+	defer runtime.HandleCrash()
+	return condition()
+}
+
 // Backoff holds parameters applied to a Backoff function.
 type Backoff struct {
 	// The initial duration.
@@ -277,6 +285,92 @@ func contextForChannel(parentCh <-chan struct{}) (context.Context, context.Cance
 	return ctx, cancel
 }
 
+// BackoffManager manages backoff with a particular scheme based on its underlying implementation. It provides
+// an interface to return a timer for backoff, and caller shall backoff until Timer.C returns. If the second Backoff()
+// is called before the timer from the first Backoff() call finishes, the first timer will NOT be drained.
+// The BackoffManager is supposed to be called in a single-threaded environment.
+type BackoffManager interface {
+	Backoff() clock.Timer
+}
+
+type exponentialBackoffManagerImpl struct {
+	backoff              *Backoff
+	backoffTimer         clock.Timer
+	lastBackoffStart     time.Time
+	initialBackoff       time.Duration
+	backoffResetDuration time.Duration
+	clock                clock.Clock
+}
+
+// NewExponentialBackoffManager returns a manager for managing exponential backoff. Each backoff is jittered and
+// backoff will not exceed the given max. If the backoff is not called within resetDuration, the backoff is reset.
+// This backoff manager is used to reduce load during upstream unhealthiness.
+func NewExponentialBackoffManager(initBackoff, maxBackoff, resetDuration time.Duration, backoffFactor, jitter float64, c clock.Clock) BackoffManager {
+	return &exponentialBackoffManagerImpl{
+		backoff: &Backoff{
+			Duration: initBackoff,
+			Factor:   backoffFactor,
+			Jitter:   jitter,
+
+			// the current impl of wait.Backoff returns Backoff.Duration once steps are used up, which is not
+			// what we ideally need here, we set it to max int and assume we will never use up the steps
+			Steps: math.MaxInt32,
+			Cap:   maxBackoff,
+		},
+		backoffTimer:         c.NewTimer(0),
+		initialBackoff:       initBackoff,
+		lastBackoffStart:     c.Now(),
+		backoffResetDuration: resetDuration,
+		clock:                c,
+	}
+}
+
+func (b *exponentialBackoffManagerImpl) getNextBackoff() time.Duration {
+	if b.clock.Now().Sub(b.lastBackoffStart) > b.backoffResetDuration {
+		b.backoff.Steps = math.MaxInt32
+		b.backoff.Duration = b.initialBackoff
+	}
+	b.lastBackoffStart = b.clock.Now()
+	return b.backoff.Step()
+}
+
+// Backoff implements BackoffManager.Backoff, it returns a timer so caller can block on the timer for backoff.
+func (b *exponentialBackoffManagerImpl) Backoff() clock.Timer {
+	b.backoffTimer.Reset(b.getNextBackoff())
+	return b.backoffTimer
+}
+
+type jitteredBackoffManagerImpl struct {
+	clock        clock.Clock
+	duration     time.Duration
+	jitter       float64
+	backoffTimer clock.Timer
+}
+
+// NewJitteredBackoffManager returns a BackoffManager that backoffs with given duration plus given jitter. If the jitter
+// is negative, backoff will not be jittered.
+func NewJitteredBackoffManager(duration time.Duration, jitter float64, c clock.Clock) BackoffManager {
+	return &jitteredBackoffManagerImpl{
+		clock:        c,
+		duration:     duration,
+		jitter:       jitter,
+		backoffTimer: c.NewTimer(0),
+	}
+}
+
+func (j *jitteredBackoffManagerImpl) getNextBackoff() time.Duration {
+	jitteredPeriod := j.duration
+	if j.jitter > 0.0 {
+		jitteredPeriod = Jitter(j.duration, j.jitter)
+	}
+	return jitteredPeriod
+}
+
+func (j *jitteredBackoffManagerImpl) Backoff() clock.Timer {
+	j.backoffTimer.Reset(j.getNextBackoff())
+	return j.backoffTimer
+}
+
 // ExponentialBackoff repeats a condition check with exponential backoff.
 //
 // It repeatedly checks the condition and then sleeps, using `backoff.Step()`
@@ -289,7 +383,7 @@ func contextForChannel(parentCh <-chan struct{}) (context.Context, context.Cance
 // In all other cases, ErrWaitTimeout is returned.
 func ExponentialBackoff(backoff Backoff, condition ConditionFunc) error {
 	for backoff.Steps > 0 {
-		if ok, err := condition(); err != nil || ok {
+		if ok, err := runConditionWithCrashProtection(condition); err != nil || ok {
 			return err
 		}
 		if backoff.Steps == 1 {
@@ -335,7 +429,7 @@ func PollImmediate(interval, timeout time.Duration, condition ConditionFunc) err
 }
 
 func pollImmediateInternal(wait WaitFunc, condition ConditionFunc) error {
-	done, err := condition()
+	done, err := runConditionWithCrashProtection(condition)
 	if err != nil {
 		return err
 	}
@@ -364,7 +458,7 @@ func PollInfinite(interval time.Duration, condition ConditionFunc) error {
 // Some intervals may be missed if the condition takes too long or the time
 // window is too short.
 func PollImmediateInfinite(interval time.Duration, condition ConditionFunc) error {
-	done, err := condition()
+	done, err := runConditionWithCrashProtection(condition)
 	if err != nil {
 		return err
 	}
@@ -431,7 +525,7 @@ func WaitFor(wait WaitFunc, fn ConditionFunc, done <-chan struct{}) error {
 	for {
 		select {
 		case _, open := <-c:
-			ok, err := fn()
+			ok, err := runConditionWithCrashProtection(fn)
 			if err != nil {
 				return err
 			}
@@ -497,16 +591,3 @@ func poller(interval, timeout time.Duration) WaitFunc {
 		return ch
 	})
 }
-
-// resetOrReuseTimer avoids allocating a new timer if one is already in use.
-// Not safe for multiple threads.
-func resetOrReuseTimer(t *time.Timer, d time.Duration, sawTimeout bool) *time.Timer {
-	if t == nil {
-		return time.NewTimer(d)
-	}
-	if !t.Stop() && !sawTimeout {
-		<-t.C
-	}
-	t.Reset(d)
-	return t
-}