Instance protection

docs/instance_groups.md

@@ -476,6 +476,27 @@ spec:
   - AZRebalance
 ```
 
+## Protect new instances from scale in
+
+Autoscaling groups may scale up or down automatically to balance types of instances, regions, etc.
+[Instance protection](https://docs.aws.amazon.com/autoscaling/ec2/userguide/as-instance-termination.html#instance-protection) prevents the ASG from being scaled in.
+
+```
+# Example for nodes
+apiVersion: kops.k8s.io/v1alpha2
+kind: InstanceGroup
+metadata:
+  labels:
+    kops.k8s.io/cluster: k8s.dev.local
+  name: nodes
+spec:
+  machineType: m4.xlarge
+  maxSize: 20
+  minSize: 2
+  role: Node
+  instanceProtection: true
+```
+
 ## Attaching existing Load Balancers to Instance Groups
 
 Instance groups can be linked to up to 10 load balancers. When attached, any instance launched will

pkg/apis/kops/instancegroup.go

@@ -149,6 +149,8 @@ type InstanceGroupSpec struct {
 	IAM *IAMProfileSpec `json:"iam,omitempty"`
 	// SecurityGroupOverride overrides the default security group created by Kops for this IG (AWS only).
 	SecurityGroupOverride *string `json:"securityGroupOverride,omitempty"`
+	// InstanceProtection makes new instances in an autoscaling group protected from scale in
+	InstanceProtection *bool `json:"instanceProtection,omitempty"`
 }
 
 const (

pkg/apis/kops/v1alpha1/instancegroup.go

@@ -136,6 +136,8 @@ type InstanceGroupSpec struct {
 	IAM *IAMProfileSpec `json:"iam,omitempty"`
 	// SecurityGroupOverride overrides the default security group created by Kops for this IG (AWS only).
 	SecurityGroupOverride *string `json:"securityGroupOverride,omitempty"`
+	// InstanceProtection makes new instances in an autoscaling group protected from scale in
+	InstanceProtection *bool `json:"instanceProtection,omitempty"`
 }
 
 const (

pkg/apis/kops/v1alpha2/instancegroup.go

@@ -143,6 +143,8 @@ type InstanceGroupSpec struct {
 	IAM *IAMProfileSpec `json:"iam,omitempty"`
 	// SecurityGroupOverride overrides the default security group created by Kops for this IG (AWS only).
 	SecurityGroupOverride *string `json:"securityGroupOverride,omitempty"`
+	// InstanceProtection makes new instances in an autoscaling group protected from scale in
+	InstanceProtection *bool `json:"instanceProtection,omitempty"`
 }
 
 const (

pkg/model/awsmodel/autoscalinggroup.go

@@ -315,6 +315,8 @@ func (b *AutoscalingGroupModelBuilder) buildAutoScalingGroupTask(c *fi.ModelBuil
 	}
 	t.SuspendProcesses = &processes
 
+	t.InstanceProtection = ig.Spec.InstanceProtection
+
 	// @step: are we using a mixed instance policy
 	if ig.Spec.MixedInstancesPolicy != nil {
 		spec := ig.Spec.MixedInstancesPolicy

tests/integration/update_cluster/mixed_instances/in-v1alpha2.yaml

@@ -68,6 +68,7 @@ spec:
   maxSize: 2
   minSize: 2
   role: Node
+  instanceProtection: true
   subnets:
   - us-test-1b
   mixedInstancesPolicy:

tests/integration/update_cluster/mixed_instances/kubernetes.tf

@@ -228,8 +228,9 @@ resource "aws_autoscaling_group" "nodes-mixedinstances-example-com" {
     propagate_at_launch = true
   }
 
-  metrics_granularity = "1Minute"
-  enabled_metrics     = ["GroupDesiredCapacity", "GroupInServiceInstances", "GroupMaxSize", "GroupMinSize", "GroupPendingInstances", "GroupStandbyInstances", "GroupTerminatingInstances", "GroupTotalInstances"]
+  metrics_granularity   = "1Minute"
+  enabled_metrics       = ["GroupDesiredCapacity", "GroupInServiceInstances", "GroupMaxSize", "GroupMinSize", "GroupPendingInstances", "GroupStandbyInstances", "GroupTerminatingInstances", "GroupTotalInstances"]
+  protect_from_scale_in = true
 }
 
 resource "aws_ebs_volume" "us-test-1a-etcd-events-mixedinstances-example-com" {

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

@@ -45,6 +45,8 @@ type AutoscalingGroup struct {
 
 	// Granularity specifys the granularity of the metrics
 	Granularity *string
+	// InstanceProtection makes new instances in an autoscaling group protected from scale in
+	InstanceProtection *bool
 	// LaunchConfiguration is the launch configuration for the autoscaling group
 	LaunchConfiguration *LaunchConfiguration
 	// LaunchTemplate is the launch template for the asg
@@ -171,6 +173,10 @@ func (e *AutoscalingGroup) Find(c *fi.Context) (*AutoscalingGroup, error) {
 	// Avoid spurious changes
 	actual.Lifecycle = e.Lifecycle
 
+	if g.NewInstancesProtectedFromScaleIn != nil {
+		actual.InstanceProtection = g.NewInstancesProtectedFromScaleIn
+	}
+
 	return actual, nil
 }
 
@@ -315,6 +321,11 @@ func (v *AutoscalingGroup) RenderAWS(t *awsup.AWSAPITarget, a, e, changes *Autos
 				return fmt.Errorf("error suspending processes: %v", err)
 			}
 		}
+
+		if e.InstanceProtection != nil {
+			request.NewInstancesProtectedFromScaleIn = e.InstanceProtection
+		}
+
 	} else {
 		// @logic: else we have found a autoscaling group and we need to evaluate the difference
 		request := &autoscaling.UpdateAutoScalingGroupInput{
@@ -451,6 +462,11 @@ func (v *AutoscalingGroup) RenderAWS(t *awsup.AWSAPITarget, a, e, changes *Autos
 			changes.SuspendProcesses = nil
 		}
 
+		if changes.InstanceProtection != nil {
+			request.NewInstancesProtectedFromScaleIn = e.InstanceProtection
+			changes.InstanceProtection = nil
+		}
+
 		empty := &AutoscalingGroup{}
 		if !reflect.DeepEqual(empty, changes) {
 			klog.Warningf("cannot apply changes to AutoScalingGroup: %v", changes)
@@ -628,6 +644,7 @@ type terraformAutoscalingGroup struct {
 	MetricsGranularity      *string                          `json:"metrics_granularity,omitempty"`
 	EnabledMetrics          []*string                        `json:"enabled_metrics,omitempty"`
 	SuspendedProcesses      []*string                        `json:"suspended_processes,omitempty"`
+	InstanceProtection      *bool                            `json:"protect_from_scale_in,omitempty"`
 }
 
 // RenderTerraform is responsible for rendering the terraform codebase
@@ -638,6 +655,7 @@ func (_ *AutoscalingGroup) RenderTerraform(t *terraform.TerraformTarget, a, e, c
 		MaxSize:            e.MaxSize,
 		MetricsGranularity: e.Granularity,
 		EnabledMetrics:     aws.StringSlice(e.Metrics),
+		InstanceProtection: e.InstanceProtection,
 	}
 
 	for _, s := range e.Subnets {