From 044b5f6d0d60ee716ffe3c965ef2884eecbf42f3 Mon Sep 17 00:00:00 2001
From: John Gardiner Myers <jgmyers@proofpoint.com>
Date: Sat, 24 Apr 2021 16:35:46 -0700
Subject: [PATCH] Allow disabling warm pool by setting WarmPool.MaxSize to 0

---
 pkg/apis/kops/instancegroup.go         | 4 ++++
 pkg/model/awsmodel/autoscalinggroup.go | 4 ++--
 pkg/model/iam.go                       | 4 ++--
 upup/pkg/fi/nodeup/command.go          | 2 +-
 4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/pkg/apis/kops/instancegroup.go b/pkg/apis/kops/instancegroup.go
index 231091a738..75e9dff75d 100644
--- a/pkg/apis/kops/instancegroup.go
+++ b/pkg/apis/kops/instancegroup.go
@@ -199,6 +199,10 @@ type WarmPoolSpec struct {
 	EnableLifecyleHook bool `json:"enableLifecycleHook,omitempty"`
 }
 
+func (in *WarmPoolSpec) IsEnabled() bool {
+	return in != nil && (in.MaxSize == nil || *in.MaxSize != 0)
+}
+
 const (
 	// SpotAllocationStrategyLowestPrices indicates a lowest-price strategy
 	SpotAllocationStrategyLowestPrices = "lowest-price"
diff --git a/pkg/model/awsmodel/autoscalinggroup.go b/pkg/model/awsmodel/autoscalinggroup.go
index da1cf999eb..5823220ad7 100644
--- a/pkg/model/awsmodel/autoscalinggroup.go
+++ b/pkg/model/awsmodel/autoscalinggroup.go
@@ -89,12 +89,12 @@ func (b *AutoscalingGroupModelBuilder) Build(c *fi.ModelBuilderContext) error {
 
 		warmPool := ig.Spec.WarmPool
 		{
-			enabled := fi.Bool(warmPool != nil)
+			enabled := fi.Bool(warmPool.IsEnabled())
 			warmPoolTask := &awstasks.WarmPool{
 				Name:    &name,
 				Enabled: enabled,
 			}
-			if warmPool != nil {
+			if warmPool.IsEnabled() {
 				warmPoolTask.MinSize = warmPool.MinSize
 				warmPoolTask.MaxSize = warmPool.MaxSize
 
diff --git a/pkg/model/iam.go b/pkg/model/iam.go
index 4de8344288..6234609dd3 100644
--- a/pkg/model/iam.go
+++ b/pkg/model/iam.go
@@ -77,7 +77,7 @@ func (b *IAMModelBuilder) Build(c *fi.ModelBuilderContext) error {
 	for profileARN, igRole := range sharedProfileARNsToIGRole {
 		lchPermissions := false
 		for _, ig := range b.InstanceGroups {
-			if ig.Spec.Role == igRole && ig.Spec.WarmPool != nil && ig.Spec.WarmPool.EnableLifecyleHook {
+			if ig.Spec.Role == igRole && ig.Spec.WarmPool.IsEnabled() && ig.Spec.WarmPool.EnableLifecyleHook {
 				lchPermissions = true
 				break
 
@@ -102,7 +102,7 @@ func (b *IAMModelBuilder) Build(c *fi.ModelBuilderContext) error {
 	for igRole := range managedRoles {
 		warmPool := false
 		for _, ig := range b.InstanceGroups {
-			if ig.Spec.Role == igRole && ig.Spec.WarmPool != nil && ig.Spec.WarmPool.EnableLifecyleHook {
+			if ig.Spec.Role == igRole && ig.Spec.WarmPool.IsEnabled() && ig.Spec.WarmPool.EnableLifecyleHook {
 				warmPool = true
 				break
 
diff --git a/upup/pkg/fi/nodeup/command.go b/upup/pkg/fi/nodeup/command.go
index e4de349689..f34bb346ac 100644
--- a/upup/pkg/fi/nodeup/command.go
+++ b/upup/pkg/fi/nodeup/command.go
@@ -361,7 +361,7 @@ func (c *NodeUpCommand) Run(out io.Writer) error {
 		klog.Exitf("error closing target: %v", err)
 	}
 
-	if modelContext.InstanceGroup.Spec.WarmPool != nil && modelContext.InstanceGroup.Spec.WarmPool.EnableLifecyleHook {
+	if modelContext.InstanceGroup.Spec.WarmPool.IsEnabled() && modelContext.InstanceGroup.Spec.WarmPool.EnableLifecyleHook {
 		if api.CloudProviderID(c.cluster.Spec.CloudProvider) == api.CloudProviderAWS {
 			err := completeWarmingLifecycleAction(cloud.(awsup.AWSCloud), modelContext)
 			if err != nil {