Add terraform target support for configuring Warm Pool

pkg/model/awsmodel/autoscalinggroup.go

@@ -100,7 +100,9 @@ func (b *AutoscalingGroupModelBuilder) Build(c *fi.CloudupModelBuilderContext) e
 			if warmPool.IsEnabled() {
 				warmPoolTask.MinSize = warmPool.MinSize
 				warmPoolTask.MaxSize = warmPool.MaxSize
-
+				tsk.WarmPool = warmPoolTask
+			} else {
+				tsk.WarmPool = nil
 			}
 			c.AddTask(warmPoolTask)
 

tests/integration/update_cluster/minimal-warmpool/kubernetes.tf

@@ -198,6 +198,10 @@ resource "aws_autoscaling_group" "nodes-minimal-warmpool-example-com" {
     value               = "owned"
   }
   vpc_zone_identifier = [aws_subnet.us-test-1a-minimal-warmpool-example-com.id]
+  warm_pool {
+    max_group_prepared_capacity = 1
+    min_size                    = 0
+  }
 }
 
 resource "aws_autoscaling_lifecycle_hook" "kops-warmpool-nodes" {

upup/pkg/fi/cloudup/awstasks/autoscalinggroup.go

@@ -98,6 +98,8 @@ type AutoscalingGroup struct {
 	TargetGroups []*TargetGroup
 	// CapacityRebalance makes ASG proactively replace spot instances when ASG receives a rebalance recommendation
 	CapacityRebalance *bool
+	// WarmPool is the WarmPool config for the ASG
+	WarmPool *WarmPool
 }
 
 var _ fi.CompareWithID = &AutoscalingGroup{}
@@ -929,6 +931,11 @@ type terraformMixedInstancesPolicy struct {
 	InstanceDistribution []*terraformAutoscalingInstanceDistribution `cty:"instances_distribution"`
 }
 
+type terraformWarmPool struct {
+	MinSize *int64 `cty:"min_size"`
+	MaxSize *int64 `cty:"max_group_prepared_capacity"`
+}
+
 type terraformAutoscalingGroup struct {
 	Name                    *string                                          `cty:"name"`
 	LaunchConfigurationName *terraformWriter.Literal                         `cty:"launch_configuration"`
@@ -946,6 +953,7 @@ type terraformAutoscalingGroup struct {
 	TargetGroupARNs         []*terraformWriter.Literal                       `cty:"target_group_arns"`
 	MaxInstanceLifetime     *int64                                           `cty:"max_instance_lifetime"`
 	CapacityRebalance       *bool                                            `cty:"capacity_rebalance"`
+	WarmPool                *terraformWarmPool                               `cty:"warm_pool"`
 }
 
 // RenderTerraform is responsible for rendering the terraform codebase
@@ -1069,6 +1077,13 @@ func (_ *AutoscalingGroup) RenderTerraform(t *terraform.TerraformTarget, a, e, c
 	}
 	tf.SuspendedProcesses = processes
 
+	if e.WarmPool != nil && *e.WarmPool.Enabled {
+		tf.WarmPool = &terraformWarmPool{
+			MinSize: &e.WarmPool.MinSize,
+			MaxSize: e.WarmPool.MaxSize,
+		}
+	}
+
 	return t.RenderResource("aws_autoscaling_group", *e.Name, tf)
 }
 

upup/pkg/fi/cloudup/awstasks/autoscalinggroup_test.go

@@ -331,6 +331,89 @@ terraform {
 }
 `,
 		},
+                {
+                        Resource: &AutoscalingGroup{
+                                Name:                        fi.PtrTo("test1"),
+                                LaunchTemplate:              &LaunchTemplate{Name: fi.PtrTo("test_lt")},
+                                MaxSize:                     fi.PtrTo(int64(10)),
+                                Metrics:                     []string{"test"},
+                                MinSize:                     fi.PtrTo(int64(5)),
+                                MixedInstanceOverrides:      []string{"t2.medium", "t2.large"},
+                                MixedOnDemandBase:           fi.PtrTo(int64(4)),
+                                MixedOnDemandAboveBase:      fi.PtrTo(int64(30)),
+                                MixedSpotAllocationStrategy: fi.PtrTo("capacity-optimized"),
+                                WarmPool: &WarmPool{
+				  Enabled: fi.PtrTo(true),
+                                  MinSize: 3,
+                                  MaxSize: fi.PtrTo(int64(5)),
+                                },
+                                Subnets: []*Subnet{
+                                        {
+                                                Name: fi.PtrTo("test-sg"),
+                                                ID:   fi.PtrTo("sg-1111"),
+                                        },
+                                },
+                                Tags: map[string]string{
+                                        "test":    "tag",
+                                        "cluster": "test",
+                                },
+                        },
+                        Expected: `provider "aws" {
+  region = "eu-west-2"
+}
+
+resource "aws_autoscaling_group" "test1" {
+  enabled_metrics = ["test"]
+  max_size        = 10
+  min_size        = 5
+  mixed_instances_policy {
+    instances_distribution {
+      on_demand_base_capacity                  = 4
+      on_demand_percentage_above_base_capacity = 30
+      spot_allocation_strategy                 = "capacity-optimized"
+    }
+    launch_template {
+      launch_template_specification {
+        launch_template_id = aws_launch_template.test_lt.id
+        version            = aws_launch_template.test_lt.latest_version
+      }
+      override {
+        instance_type = "t2.medium"
+      }
+      override {
+        instance_type = "t2.large"
+      }
+    }
+  }
+  name = "test1"
+  tag {
+    key                 = "cluster"
+    propagate_at_launch = true
+    value               = "test"
+  }
+  tag {
+    key                 = "test"
+    propagate_at_launch = true
+    value               = "tag"
+  }
+  vpc_zone_identifier = [aws_subnet.test-sg.id]
+  warm_pool {
+    max_group_prepared_capacity = 5
+    min_size                    = 3
+  }
+}
+
+terraform {
+  required_version = ">= 0.15.0"
+  required_providers {
+    aws = {
+      "source"  = "hashicorp/aws"
+      "version" = ">= 4.0.0"
+    }
+  }
+}
+`,
+                },
 	}
 
 	doRenderTests(t, "RenderTerraform", cases)

upup/pkg/fi/cloudup/awstasks/warmpool.go

@@ -20,7 +20,6 @@ import (
 	"fmt"
 
 	"github.com/aws/aws-sdk-go/service/autoscaling"
-	"k8s.io/klog/v2"
 	"k8s.io/kops/upup/pkg/fi"
 	"k8s.io/kops/upup/pkg/fi/cloudup/awsup"
 	"k8s.io/kops/upup/pkg/fi/cloudup/terraform"
@@ -118,9 +117,7 @@ func (*WarmPool) RenderAWS(t *awsup.AWSAPITarget, a, e, changes *WarmPool) error
 	return nil
 }
 
+// For the terraform target, warmpool config is rendered inside the AutoscalingGroup resource
 func (_ *WarmPool) RenderTerraform(t *terraform.TerraformTarget, a, e, changes *WarmPool) error {
-	if changes != nil {
-		klog.Warning("ASG warm pool is not supported by the terraform target")
-	}
 	return nil
 }