rebase: update kubernetes to 1.28.0 in main

updating kubernetes to 1.28.0
in the main repo.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

vendor/k8s.io/apiserver/pkg/util/flowcontrol/request/config.go

@@ -24,7 +24,7 @@ import (
 
 const (
 	minimumSeats                = 1
-	maximumSeats                = 10
+	maximumSeatsLimit           = 10
 	objectsPerSeat              = 100.0
 	watchesPerSeat              = 10.0
 	enableMutatingWorkEstimator = true
@@ -39,12 +39,13 @@ type WorkEstimatorConfig struct {
 
 	// MinimumSeats is the minimum number of seats a request must occupy.
 	MinimumSeats uint64 `json:"minimumSeats,omitempty"`
-	// MaximumSeats is the maximum number of seats a request can occupy
+
+	// MaximumSeatsLimit is an upper limit on the max seats a request can occupy.
 	//
 	// NOTE: work_estimate_seats_samples metric uses the value of maximumSeats
 	// as the upper bound, so when we change maximumSeats we should also
 	// update the buckets of the metric.
-	MaximumSeats uint64 `json:"maximumSeats,omitempty"`
+	MaximumSeatsLimit uint64 `json:"maximumSeatsLimit,omitempty"`
 }
 
 // ListWorkEstimatorConfig holds work estimator parameters related to list requests.
@@ -66,7 +67,7 @@ type MutatingWorkEstimatorConfig struct {
 func DefaultWorkEstimatorConfig() *WorkEstimatorConfig {
 	return &WorkEstimatorConfig{
 		MinimumSeats:                minimumSeats,
-		MaximumSeats:                maximumSeats,
+		MaximumSeatsLimit:           maximumSeatsLimit,
 		ListWorkEstimatorConfig:     defaultListWorkEstimatorConfig(),
 		MutatingWorkEstimatorConfig: defaultMutatingWorkEstimatorConfig(),
 	}

vendor/k8s.io/apiserver/pkg/util/flowcontrol/request/list_work_estimator.go

@@ -29,10 +29,11 @@ import (
 	"k8s.io/klog/v2"
 )
 
-func newListWorkEstimator(countFn objectCountGetterFunc, config *WorkEstimatorConfig) WorkEstimatorFunc {
+func newListWorkEstimator(countFn objectCountGetterFunc, config *WorkEstimatorConfig, maxSeatsFn maxSeatsFunc) WorkEstimatorFunc {
 	estimator := &listWorkEstimator{
 		config:        config,
 		countGetterFn: countFn,
+		maxSeatsFn:    maxSeatsFn,
 	}
 	return estimator.estimate
 }
@@ -40,14 +41,21 @@ func newListWorkEstimator(countFn objectCountGetterFunc, config *WorkEstimatorCo
 type listWorkEstimator struct {
 	config        *WorkEstimatorConfig
 	countGetterFn objectCountGetterFunc
+	maxSeatsFn    maxSeatsFunc
 }
 
 func (e *listWorkEstimator) estimate(r *http.Request, flowSchemaName, priorityLevelName string) WorkEstimate {
+	minSeats := e.config.MinimumSeats
+	maxSeats := e.maxSeatsFn(priorityLevelName)
+	if maxSeats == 0 || maxSeats > e.config.MaximumSeatsLimit {
+		maxSeats = e.config.MaximumSeatsLimit
+	}
+
 	requestInfo, ok := apirequest.RequestInfoFrom(r.Context())
 	if !ok {
 		// no RequestInfo should never happen, but to be on the safe side
 		// let's return maximumSeats
-		return WorkEstimate{InitialSeats: e.config.MaximumSeats}
+		return WorkEstimate{InitialSeats: maxSeats}
 	}
 
 	if requestInfo.Name != "" {
@@ -56,7 +64,7 @@ func (e *listWorkEstimator) estimate(r *http.Request, flowSchemaName, priorityLe
 		// Example of such list requests:
 		// /apis/certificates.k8s.io/v1/certificatesigningrequests?fieldSelector=metadata.name%3Dcsr-xxs4m
 		// /api/v1/namespaces/test/configmaps?fieldSelector=metadata.name%3Dbig-deployment-1&limit=500&resourceVersion=0
-		return WorkEstimate{InitialSeats: e.config.MinimumSeats}
+		return WorkEstimate{InitialSeats: minSeats}
 	}
 
 	query := r.URL.Query()
@@ -66,9 +74,18 @@ func (e *listWorkEstimator) estimate(r *http.Request, flowSchemaName, priorityLe
 
 		// This request is destined to fail in the validation layer,
 		// return maximumSeats for this request to be consistent.
-		return WorkEstimate{InitialSeats: e.config.MaximumSeats}
+		return WorkEstimate{InitialSeats: maxSeats}
 	}
-	isListFromCache := !shouldListFromStorage(query, &listOptions)
+
+	// For watch requests, we want to adjust the cost only if they explicitly request
+	// sending initial events.
+	if requestInfo.Verb == "watch" {
+		if listOptions.SendInitialEvents == nil || !*listOptions.SendInitialEvents {
+			return WorkEstimate{InitialSeats: e.config.MinimumSeats}
+		}
+	}
+
+	isListFromCache := requestInfo.Verb == "watch" || !shouldListFromStorage(query, &listOptions)
 
 	numStored, err := e.countGetterFn(key(requestInfo))
 	switch {
@@ -77,7 +94,7 @@ func (e *listWorkEstimator) estimate(r *http.Request, flowSchemaName, priorityLe
 		// be conservative here and allocate maximum seats to this list request.
 		// NOTE: if a CRD is removed, its count will go stale first and then the
 		// pruner will eventually remove the CRD from the cache.
-		return WorkEstimate{InitialSeats: e.config.MaximumSeats}
+		return WorkEstimate{InitialSeats: maxSeats}
 	case err == ObjectCountNotFoundErr:
 		// there are multiple scenarios in which we can see this error:
 		//  a. the type is truly unknown, a typo on the caller's part.
@@ -91,12 +108,12 @@ func (e *listWorkEstimator) estimate(r *http.Request, flowSchemaName, priorityLe
 		// when aggregated API calls are overestimated, we allocate the minimum
 		// possible seats (see #109106 as an example when being more conservative
 		// led to problems).
-		return WorkEstimate{InitialSeats: e.config.MinimumSeats}
+		return WorkEstimate{InitialSeats: minSeats}
 	case err != nil:
 		// we should never be here since Get returns either ObjectCountStaleErr or
 		// ObjectCountNotFoundErr, return maximumSeats to be on the safe side.
 		klog.ErrorS(err, "Unexpected error from object count tracker")
-		return WorkEstimate{InitialSeats: e.config.MaximumSeats}
+		return WorkEstimate{InitialSeats: maxSeats}
 	}
 
 	limit := numStored
@@ -125,11 +142,11 @@ func (e *listWorkEstimator) estimate(r *http.Request, flowSchemaName, priorityLe
 	seats := uint64(math.Ceil(float64(estimatedObjectsToBeProcessed) / e.config.ObjectsPerSeat))
 
 	// make sure we never return a seat of zero
-	if seats < e.config.MinimumSeats {
-		seats = e.config.MinimumSeats
+	if seats < minSeats {
+		seats = minSeats
 	}
-	if seats > e.config.MaximumSeats {
-		seats = e.config.MaximumSeats
+	if seats > maxSeats {
+		seats = maxSeats
 	}
 	return WorkEstimate{InitialSeats: seats}
 }
@@ -149,9 +166,16 @@ func shouldListFromStorage(query url.Values, opts *metav1.ListOptions) bool {
 	resourceVersion := opts.ResourceVersion
 	match := opts.ResourceVersionMatch
 	pagingEnabled := utilfeature.DefaultFeatureGate.Enabled(features.APIListChunking)
+	consistentListFromCacheEnabled := utilfeature.DefaultFeatureGate.Enabled(features.ConsistentListFromCache)
+
+	// Serve consistent reads from storage if ConsistentListFromCache is disabled
+	consistentReadFromStorage := resourceVersion == "" && !consistentListFromCacheEnabled
+	// Watch cache doesn't support continuations, so serve them from etcd.
 	hasContinuation := pagingEnabled && len(opts.Continue) > 0
+	// Serve paginated requests about revision "0" from watch cache to avoid overwhelming etcd.
 	hasLimit := pagingEnabled && opts.Limit > 0 && resourceVersion != "0"
+	// Watch cache only supports ResourceVersionMatchNotOlderThan (default).
 	unsupportedMatch := match != "" && match != metav1.ResourceVersionMatchNotOlderThan
 
-	return resourceVersion == "" || hasContinuation || hasLimit || unsupportedMatch
+	return consistentReadFromStorage || hasContinuation || hasLimit || unsupportedMatch
 }

vendor/k8s.io/apiserver/pkg/util/flowcontrol/request/mutating_work_estimator.go

@@ -25,25 +25,33 @@ import (
 	"k8s.io/apiserver/pkg/util/flowcontrol/metrics"
 )
 
-func newMutatingWorkEstimator(countFn watchCountGetterFunc, config *WorkEstimatorConfig) WorkEstimatorFunc {
+func newMutatingWorkEstimator(countFn watchCountGetterFunc, config *WorkEstimatorConfig, maxSeatsFn maxSeatsFunc) WorkEstimatorFunc {
 	estimator := &mutatingWorkEstimator{
-		config:  config,
-		countFn: countFn,
+		config:     config,
+		countFn:    countFn,
+		maxSeatsFn: maxSeatsFn,
 	}
 	return estimator.estimate
 }
 
 type mutatingWorkEstimator struct {
-	config  *WorkEstimatorConfig
-	countFn watchCountGetterFunc
+	config     *WorkEstimatorConfig
+	countFn    watchCountGetterFunc
+	maxSeatsFn maxSeatsFunc
 }
 
 func (e *mutatingWorkEstimator) estimate(r *http.Request, flowSchemaName, priorityLevelName string) WorkEstimate {
+	minSeats := e.config.MinimumSeats
+	maxSeats := e.maxSeatsFn(priorityLevelName)
+	if maxSeats == 0 || maxSeats > e.config.MaximumSeatsLimit {
+		maxSeats = e.config.MaximumSeatsLimit
+	}
+
 	// TODO(wojtekt): Remove once we tune the algorithm to not fail
 	// scalability tests.
 	if !e.config.Enabled {
 		return WorkEstimate{
-			InitialSeats: 1,
+			InitialSeats: minSeats,
 		}
 	}
 
@@ -52,15 +60,15 @@ func (e *mutatingWorkEstimator) estimate(r *http.Request, flowSchemaName, priori
 		// no RequestInfo should never happen, but to be on the safe side
 		// let's return a large value.
 		return WorkEstimate{
-			InitialSeats:      1,
-			FinalSeats:        e.config.MaximumSeats,
+			InitialSeats:      minSeats,
+			FinalSeats:        maxSeats,
 			AdditionalLatency: e.config.eventAdditionalDuration(),
 		}
 	}
 
 	if isRequestExemptFromWatchEvents(requestInfo) {
 		return WorkEstimate{
-			InitialSeats:      e.config.MinimumSeats,
+			InitialSeats:      minSeats,
 			FinalSeats:        0,
 			AdditionalLatency: time.Duration(0),
 		}
@@ -126,8 +134,8 @@ func (e *mutatingWorkEstimator) estimate(r *http.Request, flowSchemaName, priori
 		//
 		// TODO: Confirm that the current cap of maximumSeats allow us to
 		//   achieve the above.
-		if finalSeats > e.config.MaximumSeats {
-			finalSeats = e.config.MaximumSeats
+		if finalSeats > maxSeats {
+			finalSeats = maxSeats
 		}
 		additionalLatency = finalWork.DurationPerSeat(float64(finalSeats))
 	}

vendor/k8s.io/apiserver/pkg/util/flowcontrol/request/seat_seconds.go

@@ -38,7 +38,7 @@ const MinSeatSeconds = SeatSeconds(0)
 // This is intended only to produce small values, increments in work
 // rather than amount of work done since process start.
 func SeatsTimesDuration(seats float64, duration time.Duration) SeatSeconds {
-	return SeatSeconds(math.Round(seats * float64(duration/time.Nanosecond) / (1e9 / ssScale)))
+	return SeatSeconds(int64(math.Round(seats * float64(duration/time.Nanosecond) / (1e9 / ssScale))))
 }
 
 // ToFloat converts to a floating-point representation.

vendor/k8s.io/apiserver/pkg/util/flowcontrol/request/width.go

@@ -22,6 +22,9 @@ import (
 	"time"
 
 	apirequest "k8s.io/apiserver/pkg/endpoints/request"
+	"k8s.io/apiserver/pkg/features"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
+
 	"k8s.io/klog/v2"
 )
 
@@ -61,15 +64,19 @@ type objectCountGetterFunc func(string) (int64, error)
 // number of watchers potentially interested in a given request.
 type watchCountGetterFunc func(*apirequest.RequestInfo) int
 
+// MaxSeatsFunc represents a function that returns the maximum seats
+// allowed for the work estimator for a given priority level.
+type maxSeatsFunc func(priorityLevelName string) uint64
+
 // NewWorkEstimator estimates the work that will be done by a given request,
 // if no WorkEstimatorFunc matches the given request then the default
 // work estimate of 1 seat is allocated to the request.
-func NewWorkEstimator(objectCountFn objectCountGetterFunc, watchCountFn watchCountGetterFunc, config *WorkEstimatorConfig) WorkEstimatorFunc {
+func NewWorkEstimator(objectCountFn objectCountGetterFunc, watchCountFn watchCountGetterFunc, config *WorkEstimatorConfig, maxSeatsFn maxSeatsFunc) WorkEstimatorFunc {
 	estimator := &workEstimator{
 		minimumSeats:          config.MinimumSeats,
-		maximumSeats:          config.MaximumSeats,
-		listWorkEstimator:     newListWorkEstimator(objectCountFn, config),
-		mutatingWorkEstimator: newMutatingWorkEstimator(watchCountFn, config),
+		maximumSeatsLimit:     config.MaximumSeatsLimit,
+		listWorkEstimator:     newListWorkEstimator(objectCountFn, config, maxSeatsFn),
+		mutatingWorkEstimator: newMutatingWorkEstimator(watchCountFn, config, maxSeatsFn),
 	}
 	return estimator.estimate
 }
@@ -86,8 +93,8 @@ func (e WorkEstimatorFunc) EstimateWork(r *http.Request, flowSchemaName, priorit
 type workEstimator struct {
 	// the minimum number of seats a request must occupy
 	minimumSeats uint64
-	// the maximum number of seats a request can occupy
-	maximumSeats uint64
+	// the default maximum number of seats a request can occupy
+	maximumSeatsLimit uint64
 	// listWorkEstimator estimates work for list request(s)
 	listWorkEstimator WorkEstimatorFunc
 	// mutatingWorkEstimator calculates the width of mutating request(s)
@@ -99,12 +106,21 @@ func (e *workEstimator) estimate(r *http.Request, flowSchemaName, priorityLevelN
 	if !ok {
 		klog.ErrorS(fmt.Errorf("no RequestInfo found in context"), "Failed to estimate work for the request", "URI", r.RequestURI)
 		// no RequestInfo should never happen, but to be on the safe side let's return maximumSeats
-		return WorkEstimate{InitialSeats: e.maximumSeats}
+		return WorkEstimate{InitialSeats: e.maximumSeatsLimit}
 	}
 
 	switch requestInfo.Verb {
 	case "list":
 		return e.listWorkEstimator.EstimateWork(r, flowSchemaName, priorityLevelName)
+	case "watch":
+		// WATCH supports `SendInitialEvents` option, which effectively means
+		// that is starts with sending of the contents of a corresponding LIST call.
+		// From that perspective, given that the watch only consumes APF seats
+		// during its initialization (sending init events), its cost should then
+		// be computed the same way as for a regular list.
+		if utilfeature.DefaultFeatureGate.Enabled(features.WatchList) {
+			return e.listWorkEstimator.EstimateWork(r, flowSchemaName, priorityLevelName)
+		}
 	case "create", "update", "patch", "delete":
 		return e.mutatingWorkEstimator.EstimateWork(r, flowSchemaName, priorityLevelName)
 	}