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add restriction for traffic configuration of partition-style step
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Signed-off-by: yunbo <[email protected]>
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@Funinu
Funinu committed Aug 1, 2024
1 parent 16a3f0a commit 99e10a5
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Showing 7 changed files with 3,099 additions and 3,247 deletions.
91 changes: 60 additions & 31 deletions pkg/webhook/rollout/validating/rollout_create_update_handler.go
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@ package validating

import (
"context"
"flag"
"fmt"
"net/http"
"reflect"
Expand Down Expand Up @@ -47,7 +48,29 @@ type RolloutCreateUpdateHandler struct {
Decoder *admission.Decoder
}

var _ admission.Handler = &RolloutCreateUpdateHandler{}
var (
_ admission.Handler = &RolloutCreateUpdateHandler{}
// PartitionReplicasLimitWithTraffic represents the maximum percentage of replicas
// allowed for a step of partition-style release, if traffic/matches specified.
// If a step is configured with a number of replicas exceeding this percentage, the traffic strategy for that step
// must not be specified. If this rule is violated, the Rollout webhook will block the creation or modification of the Rollout.
// The default limit is set to 50%.
// Here is why we set this limit for partition style release:
// In rollback and continuous scenarios, usually we expect the Rollout to route all traffic to the stable version first.
// However, if the stable version's pods are relatively few (less than 1-PartitionReplicasLimitWithTraffic), this might overload the stable version's pods.
// Therefore, even if users were allowed to configure traffic when the new version's replicas exceed this threshold,
// during rollback, traffic will still be evenly distributed across all backend pods if the stable version's pods are relatively few.
PartitionReplicasLimitWithTraffic = 50
)

func init() {
flag.IntVar(&PartitionReplicasLimitWithTraffic, "partition-percent-limit", 50, "represents the maximum percentage of replicas allowed for a step of partition-style release, if traffic/matches specified.")
}

// record upper level information about the rollout
type validateContext struct {
style string
}

// Handle handles admission requests.
func (h *RolloutCreateUpdateHandler) Handle(ctx context.Context, req admission.Request) admission.Response {
Expand Down Expand Up @@ -155,7 +178,7 @@ func (h *RolloutCreateUpdateHandler) validateRolloutUpdate(oldObj, newObj *appsv
}

func (h *RolloutCreateUpdateHandler) validateRollout(rollout *appsv1beta1.Rollout) field.ErrorList {
errList := validateRolloutSpec(rollout, field.NewPath("Spec"))
errList := validateRolloutSpec(GetContextFromv1beta1Rollout(rollout), rollout, field.NewPath("Spec"))
errList = append(errList, h.validateRolloutConflict(rollout, field.NewPath("Conflict Checker"))...)
return errList
}
Expand All @@ -178,9 +201,9 @@ func (h *RolloutCreateUpdateHandler) validateRolloutConflict(rollout *appsv1beta
return nil
}

func validateRolloutSpec(rollout *appsv1beta1.Rollout, fldPath *field.Path) field.ErrorList {
func validateRolloutSpec(c *validateContext, rollout *appsv1beta1.Rollout, fldPath *field.Path) field.ErrorList {
errList := validateRolloutSpecObjectRef(&rollout.Spec.WorkloadRef, fldPath.Child("ObjectRef"))
errList = append(errList, validateRolloutSpecStrategy(&rollout.Spec.Strategy, fldPath.Child("Strategy"))...)
errList = append(errList, validateRolloutSpecStrategy(c, &rollout.Spec.Strategy, fldPath.Child("Strategy"))...)
return errList
}

Expand All @@ -196,33 +219,21 @@ func validateRolloutSpecObjectRef(workloadRef *appsv1beta1.ObjectRef, fldPath *f
return nil
}

func validateRolloutSpecStrategy(strategy *appsv1beta1.RolloutStrategy, fldPath *field.Path) field.ErrorList {
func validateRolloutSpecStrategy(c *validateContext, strategy *appsv1beta1.RolloutStrategy, fldPath *field.Path) field.ErrorList {
if strategy.Canary == nil && strategy.BlueGreen == nil {
return field.ErrorList{field.Invalid(fldPath, nil, "Canary and BlueGreen cannot both be empty")}
}
if strategy.Canary != nil && strategy.BlueGreen != nil {
return field.ErrorList{field.Invalid(fldPath, nil, "Canary and BlueGreen cannot both be set")}
}
if strategy.BlueGreen != nil {
return validateRolloutSpecBlueGreenStrategy(strategy.BlueGreen, fldPath.Child("BlueGreen"))
return validateRolloutSpecBlueGreenStrategy(c, strategy.BlueGreen, fldPath.Child("BlueGreen"))
}
return validateRolloutSpecCanaryStrategy(strategy.Canary, fldPath.Child("Canary"))
return validateRolloutSpecCanaryStrategy(c, strategy.Canary, fldPath.Child("Canary"))
}

type TrafficRule string

const (
TrafficRuleCanary TrafficRule = "Canary"
TrafficRuleBlueGreen TrafficRule = "BlueGreen"
NoTraffic TrafficRule = "NoTraffic"
)

func validateRolloutSpecCanaryStrategy(canary *appsv1beta1.CanaryStrategy, fldPath *field.Path) field.ErrorList {
trafficRule := NoTraffic
if len(canary.TrafficRoutings) > 0 {
trafficRule = TrafficRuleCanary
}
errList := validateRolloutSpecCanarySteps(canary.Steps, fldPath.Child("Steps"), trafficRule)
func validateRolloutSpecCanaryStrategy(c *validateContext, canary *appsv1beta1.CanaryStrategy, fldPath *field.Path) field.ErrorList {
errList := validateRolloutSpecCanarySteps(c, canary.Steps, fldPath.Child("Steps"))
if len(canary.TrafficRoutings) > 1 {
errList = append(errList, field.Invalid(fldPath, canary.TrafficRoutings, "Rollout currently only support single TrafficRouting."))
}
Expand All @@ -232,12 +243,8 @@ func validateRolloutSpecCanaryStrategy(canary *appsv1beta1.CanaryStrategy, fldPa
return errList
}

func validateRolloutSpecBlueGreenStrategy(blueGreen *appsv1beta1.BlueGreenStrategy, fldPath *field.Path) field.ErrorList {
trafficRule := NoTraffic
if len(blueGreen.TrafficRoutings) > 0 {
trafficRule = TrafficRuleBlueGreen
}
errList := validateRolloutSpecCanarySteps(blueGreen.Steps, fldPath.Child("Steps"), trafficRule)
func validateRolloutSpecBlueGreenStrategy(c *validateContext, blueGreen *appsv1beta1.BlueGreenStrategy, fldPath *field.Path) field.ErrorList {
errList := validateRolloutSpecCanarySteps(c, blueGreen.Steps, fldPath.Child("Steps"))
if len(blueGreen.TrafficRoutings) > 1 {
errList = append(errList, field.Invalid(fldPath, blueGreen.TrafficRoutings, "Rollout currently only support single TrafficRouting."))
}
Expand Down Expand Up @@ -275,7 +282,7 @@ func validateRolloutSpecCanaryTraffic(traffic appsv1beta1.TrafficRoutingRef, fld
return errList
}

func validateRolloutSpecCanarySteps(steps []appsv1beta1.CanaryStep, fldPath *field.Path, trafficRule TrafficRule) field.ErrorList {
func validateRolloutSpecCanarySteps(c *validateContext, steps []appsv1beta1.CanaryStep, fldPath *field.Path) field.ErrorList {
stepCount := len(steps)
if stepCount == 0 {
return field.ErrorList{field.Invalid(fldPath, steps, "The number of Canary.Steps cannot be empty")}
Expand All @@ -293,13 +300,24 @@ func validateRolloutSpecCanarySteps(steps []appsv1beta1.CanaryStep, fldPath *fie
return field.ErrorList{field.Invalid(fldPath.Index(i).Child("Replicas"),
s.Replicas, `replicas must be positive number, or a percentage with "0%" < canaryReplicas <= "100%"`)}
}
if trafficRule == NoTraffic || s.Traffic == nil {
// no traffic strategy is configured for current step
if s.Traffic == nil && len(s.Matches) == 0 {
continue
}
// replicas is percentage
if c.style == string(appsv1beta1.PartitionRollingStyle) && IsPercentageCanaryReplicasType(s.Replicas) {
currCanaryReplicas, _ := intstr.GetScaledValueFromIntOrPercent(s.Replicas, 100, true)
if currCanaryReplicas > PartitionReplicasLimitWithTraffic {
return field.ErrorList{field.Invalid(fldPath.Index(i).Child("steps"), steps, `For partition style rollout: step[x].replicas must not greater than partition-percent-limit if traffic specified`)}
}
}
if s.Traffic == nil {
continue
}
is := intstr.FromString(*s.Traffic)
weight, err := intstr.GetScaledValueFromIntOrPercent(&is, 100, true)
switch trafficRule {
case TrafficRuleBlueGreen:
switch c.style {
case string(appsv1beta1.BlueGreenRollingStyle):
// traffic "0%" is allowed in blueGreen strategy
if err != nil || weight < 0 || weight > 100 {
return field.ErrorList{field.Invalid(fldPath.Index(i).Child("steps"), steps, `traffic must be percentage with "0%" <= traffic <= "100%" in blueGreen strategy`)}
Expand Down Expand Up @@ -355,3 +373,14 @@ func (h *RolloutCreateUpdateHandler) InjectDecoder(d *admission.Decoder) error {
h.Decoder = d
return nil
}

func GetContextFromv1beta1Rollout(rollout *appsv1beta1.Rollout) *validateContext {
if rollout.Spec.Strategy.Canary == nil && rollout.Spec.Strategy.BlueGreen == nil {
return nil
}
style := rollout.Spec.Strategy.GetRollingStyle()
if appsv1beta1.IsRealPartition(rollout) {
style = appsv1beta1.PartitionRollingStyle
}
return &validateContext{style: string(style)}
}
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