Update to kube v1.17

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

vendor/k8s.io/kubectl/pkg/scale/scale.go

@@ -0,0 +1,189 @@
+/*
+Copyright 2014 The Kubernetes Authors.
+
+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.
+*/
+
+package scale
+
+import (
+	"fmt"
+	"strconv"
+	"time"
+
+	autoscalingv1 "k8s.io/api/autoscaling/v1"
+	"k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/wait"
+	scaleclient "k8s.io/client-go/scale"
+)
+
+// Scaler provides an interface for resources that can be scaled.
+type Scaler interface {
+	// Scale scales the named resource after checking preconditions. It optionally
+	// retries in the event of resource version mismatch (if retry is not nil),
+	// and optionally waits until the status of the resource matches newSize (if wait is not nil)
+	// TODO: Make the implementation of this watch-based (#56075) once #31345 is fixed.
+	Scale(namespace, name string, newSize uint, preconditions *ScalePrecondition, retry, wait *RetryParams, gvr schema.GroupVersionResource) error
+	// ScaleSimple does a simple one-shot attempt at scaling - not useful on its own, but
+	// a necessary building block for Scale
+	ScaleSimple(namespace, name string, preconditions *ScalePrecondition, newSize uint, gvr schema.GroupVersionResource) (updatedResourceVersion string, err error)
+}
+
+// NewScaler get a scaler for a given resource
+func NewScaler(scalesGetter scaleclient.ScalesGetter) Scaler {
+	return &genericScaler{scalesGetter}
+}
+
+// ScalePrecondition describes a condition that must be true for the scale to take place
+// If CurrentSize == -1, it is ignored.
+// If CurrentResourceVersion is the empty string, it is ignored.
+// Otherwise they must equal the values in the resource for it to be valid.
+type ScalePrecondition struct {
+	Size            int
+	ResourceVersion string
+}
+
+// A PreconditionError is returned when a resource fails to match
+// the scale preconditions passed to kubectl.
+type PreconditionError struct {
+	Precondition  string
+	ExpectedValue string
+	ActualValue   string
+}
+
+func (pe PreconditionError) Error() string {
+	return fmt.Sprintf("Expected %s to be %s, was %s", pe.Precondition, pe.ExpectedValue, pe.ActualValue)
+}
+
+// RetryParams encapsulates the retry parameters used by kubectl's scaler.
+type RetryParams struct {
+	Interval, Timeout time.Duration
+}
+
+func NewRetryParams(interval, timeout time.Duration) *RetryParams {
+	return &RetryParams{interval, timeout}
+}
+
+// ScaleCondition is a closure around Scale that facilitates retries via util.wait
+func ScaleCondition(r Scaler, precondition *ScalePrecondition, namespace, name string, count uint, updatedResourceVersion *string, gvr schema.GroupVersionResource) wait.ConditionFunc {
+	return func() (bool, error) {
+		rv, err := r.ScaleSimple(namespace, name, precondition, count, gvr)
+		if updatedResourceVersion != nil {
+			*updatedResourceVersion = rv
+		}
+		// Retry only on update conflicts.
+		if errors.IsConflict(err) {
+			return false, nil
+		}
+		if err != nil {
+			return false, err
+		}
+		return true, nil
+	}
+}
+
+// validateGeneric ensures that the preconditions match. Returns nil if they are valid, otherwise an error
+func (precondition *ScalePrecondition) validate(scale *autoscalingv1.Scale) error {
+	if precondition.Size != -1 && int(scale.Spec.Replicas) != precondition.Size {
+		return PreconditionError{"replicas", strconv.Itoa(precondition.Size), strconv.Itoa(int(scale.Spec.Replicas))}
+	}
+	if len(precondition.ResourceVersion) > 0 && scale.ResourceVersion != precondition.ResourceVersion {
+		return PreconditionError{"resource version", precondition.ResourceVersion, scale.ResourceVersion}
+	}
+	return nil
+}
+
+// genericScaler can update scales for resources in a particular namespace
+type genericScaler struct {
+	scaleNamespacer scaleclient.ScalesGetter
+}
+
+var _ Scaler = &genericScaler{}
+
+// ScaleSimple updates a scale of a given resource. It returns the resourceVersion of the scale if the update was successful.
+func (s *genericScaler) ScaleSimple(namespace, name string, preconditions *ScalePrecondition, newSize uint, gvr schema.GroupVersionResource) (updatedResourceVersion string, err error) {
+	if preconditions != nil {
+		scale, err := s.scaleNamespacer.Scales(namespace).Get(gvr.GroupResource(), name)
+		if err != nil {
+			return "", err
+		}
+		if err = preconditions.validate(scale); err != nil {
+			return "", err
+		}
+		scale.Spec.Replicas = int32(newSize)
+		updatedScale, err := s.scaleNamespacer.Scales(namespace).Update(gvr.GroupResource(), scale)
+		if err != nil {
+			return "", err
+		}
+		return updatedScale.ResourceVersion, nil
+	}
+
+	patch := []byte(fmt.Sprintf(`{"spec":{"replicas":%d}}`, newSize))
+	updatedScale, err := s.scaleNamespacer.Scales(namespace).Patch(gvr, name, types.MergePatchType, patch)
+	if err != nil {
+		return "", err
+	}
+	return updatedScale.ResourceVersion, nil
+}
+
+// Scale updates a scale of a given resource to a new size, with optional precondition check (if preconditions is not nil),
+// optional retries (if retry is not nil), and then optionally waits for the status to reach desired count.
+func (s *genericScaler) Scale(namespace, resourceName string, newSize uint, preconditions *ScalePrecondition, retry, waitForReplicas *RetryParams, gvr schema.GroupVersionResource) error {
+	if retry == nil {
+		// make it try only once, immediately
+		retry = &RetryParams{Interval: time.Millisecond, Timeout: time.Millisecond}
+	}
+	cond := ScaleCondition(s, preconditions, namespace, resourceName, newSize, nil, gvr)
+	if err := wait.PollImmediate(retry.Interval, retry.Timeout, cond); err != nil {
+		return err
+	}
+	if waitForReplicas != nil {
+		return WaitForScaleHasDesiredReplicas(s.scaleNamespacer, gvr.GroupResource(), resourceName, namespace, newSize, waitForReplicas)
+	}
+	return nil
+}
+
+// scaleHasDesiredReplicas returns a condition that will be true if and only if the desired replica
+// count for a scale (Spec) equals its updated replicas count (Status)
+func scaleHasDesiredReplicas(sClient scaleclient.ScalesGetter, gr schema.GroupResource, resourceName string, namespace string, desiredReplicas int32) wait.ConditionFunc {
+	return func() (bool, error) {
+		actualScale, err := sClient.Scales(namespace).Get(gr, resourceName)
+		if err != nil {
+			return false, err
+		}
+		// this means the desired scale target has been reset by something else
+		if actualScale.Spec.Replicas != desiredReplicas {
+			return true, nil
+		}
+		return actualScale.Spec.Replicas == actualScale.Status.Replicas &&
+			desiredReplicas == actualScale.Status.Replicas, nil
+	}
+}
+
+// WaitForScaleHasDesiredReplicas waits until condition scaleHasDesiredReplicas is satisfied
+// or returns error when timeout happens
+func WaitForScaleHasDesiredReplicas(sClient scaleclient.ScalesGetter, gr schema.GroupResource, resourceName string, namespace string, newSize uint, waitForReplicas *RetryParams) error {
+	if waitForReplicas == nil {
+		return fmt.Errorf("waitForReplicas parameter cannot be nil")
+	}
+	err := wait.PollImmediate(
+		waitForReplicas.Interval,
+		waitForReplicas.Timeout,
+		scaleHasDesiredReplicas(sClient, gr, resourceName, namespace, int32(newSize)))
+	if err == wait.ErrWaitTimeout {
+		return fmt.Errorf("timed out waiting for %q to be synced", resourceName)
+	}
+	return err
+}