Fix: Setting default values for scale_in_protected_instances and standby_instances as per documentation

.changelog/33382.txt

@@ -0,0 +1,7 @@
+```release-note:bug
+resource/aws_autoscaling_group: Fix `ValidationError` errors when starting Auto Scaling group instance refresh
+```
+
+```release-note:enhancement
+resource/aws_autoscaling_group: Change the default values of `instance_refresh.preferences.scale_in_protected_instances` and `instance_refresh.preferences.standby_instances` from `Wait` to the [Amazon EC2 Auto Scaling console recommended value](https://docs.aws.amazon.com/autoscaling/ec2/userguide/understand-instance-refresh-default-values.html) of `Ignore`
+```

internal/service/autoscaling/group.go

@@ -211,6 +211,7 @@ func ResourceGroup() *schema.Resource {
 									"scale_in_protected_instances": {
 										Type:         schema.TypeString,
 										Optional:     true,
+										Default:      autoscaling.ScaleInProtectedInstancesIgnore,
 										ValidateFunc: validation.StringInSlice(autoscaling.ScaleInProtectedInstances_Values(), false),
 									},
 									"skip_matching": {
@@ -221,6 +222,7 @@ func ResourceGroup() *schema.Resource {
 									"standby_instances": {
 										Type:         schema.TypeString,
 										Optional:     true,
+										Default:      autoscaling.StandbyInstancesIgnore,
 										ValidateFunc: validation.StringInSlice(autoscaling.StandbyInstances_Values(), false),
 									},
 								},

internal/service/autoscaling/group_test.go

@@ -1222,9 +1222,9 @@ func TestAccAutoScalingGroup_InstanceRefresh_basic(t *testing.T) {
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.checkpoint_percentages.#", "0"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.instance_warmup", ""),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.min_healthy_percentage", "0"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", ""),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", "Ignore"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.skip_matching", "false"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", ""),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", "Ignore"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.strategy", "Rolling"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.triggers.#", "0"),
 				),
@@ -1240,9 +1240,9 @@ func TestAccAutoScalingGroup_InstanceRefresh_basic(t *testing.T) {
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.checkpoint_percentages.#", "0"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.instance_warmup", ""),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.min_healthy_percentage", "0"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", ""),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", "Ignore"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.skip_matching", "true"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", ""),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", "Ignore"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.strategy", "Rolling"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.triggers.#", "0"),
 				),
@@ -1258,9 +1258,9 @@ func TestAccAutoScalingGroup_InstanceRefresh_basic(t *testing.T) {
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.checkpoint_percentages.#", "0"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.instance_warmup", ""),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.min_healthy_percentage", "0"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", "Ignore"),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", "Wait"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.skip_matching", "false"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", ""),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", "Ignore"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.strategy", "Rolling"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.triggers.#", "0"),
 				),
@@ -1276,9 +1276,9 @@ func TestAccAutoScalingGroup_InstanceRefresh_basic(t *testing.T) {
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.checkpoint_percentages.#", "0"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.instance_warmup", ""),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.min_healthy_percentage", "0"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", ""),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", "Ignore"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.skip_matching", "false"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", "Ignore"),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", "Wait"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.strategy", "Rolling"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.triggers.#", "0"),
 				),
@@ -1299,9 +1299,9 @@ func TestAccAutoScalingGroup_InstanceRefresh_basic(t *testing.T) {
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.checkpoint_percentages.4", "100"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.instance_warmup", "10"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.min_healthy_percentage", "50"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", ""),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", "Refresh"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.skip_matching", "false"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", ""),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", "Terminate"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.strategy", "Rolling"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.triggers.#", "0"),
 				),
@@ -1424,9 +1424,9 @@ func TestAccAutoScalingGroup_InstanceRefresh_autoRollback(t *testing.T) {
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.checkpoint_percentages.#", "0"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.instance_warmup", ""),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.min_healthy_percentage", "0"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", ""),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", "Ignore"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.skip_matching", "false"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", ""),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", "Ignore"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.strategy", "Rolling"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.triggers.#", "0"),
 				),
@@ -1442,9 +1442,9 @@ func TestAccAutoScalingGroup_InstanceRefresh_autoRollback(t *testing.T) {
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.checkpoint_percentages.#", "0"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.instance_warmup", ""),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.min_healthy_percentage", "0"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", ""),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.scale_in_protected_instances", "Ignore"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.skip_matching", "false"),
-					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", ""),
+					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.preferences.0.standby_instances", "Ignore"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.strategy", "Rolling"),
 					resource.TestCheckResourceAttr(resourceName, "instance_refresh.0.triggers.#", "0"),
 				),
@@ -4944,7 +4944,7 @@ resource "aws_autoscaling_group" "test" {
 
     preferences {
       min_healthy_percentage       = 0
-      scale_in_protected_instances = "Ignore"
+      scale_in_protected_instances = "Wait"
     }
   }
 
@@ -4972,7 +4972,7 @@ resource "aws_autoscaling_group" "test" {
 
     preferences {
       min_healthy_percentage = 0
-      standby_instances      = "Ignore"
+      standby_instances      = "Wait"
     }
   }
 
@@ -5035,6 +5035,9 @@ resource "aws_autoscaling_group" "test" {
       min_healthy_percentage = 50
       checkpoint_delay       = 25
       checkpoint_percentages = [1, 20, 25, 50, 100]
+
+      scale_in_protected_instances = "Refresh"
+      standby_instances            = "Terminate"
     }
   }
 

website/docs/r/autoscaling_group.html.markdown

@@ -658,8 +658,8 @@ This configuration block supports the following:
     - `min_healthy_percentage` - (Optional) Amount of capacity in the Auto Scaling group that must remain healthy during an instance refresh to allow the operation to continue, as a percentage of the desired capacity of the Auto Scaling group. Defaults to `90`.
     - `skip_matching` - (Optional) Replace instances that already have your desired configuration. Defaults to `false`.
     - `auto_rollback` - (Optional) Automatically rollback if instance refresh fails. Defaults to `false`. This option may only be set to `true` when specifying a `launch_template` or `mixed_instances_policy`.
-    - `scale_in_protected_instances` - (Optional) Behavior when encountering instances protected from scale in are found. Available behaviors are `Refresh`, `Ignore`, and `Wait`. Default is `Wait`.
-    - `standby_instances` - (Optional) Behavior when encountering instances in the `Standby` state in are found. Available behaviors are `Terminate`, `Ignore`, and `Wait`. Default is `Wait`.
+    - `scale_in_protected_instances` - (Optional) Behavior when encountering instances protected from scale in are found. Available behaviors are `Refresh`, `Ignore`, and `Wait`. Default is `Ignore`.
+    - `standby_instances` - (Optional) Behavior when encountering instances in the `Standby` state in are found. Available behaviors are `Terminate`, `Ignore`, and `Wait`. Default is `Ignore`.
 - `triggers` - (Optional) Set of additional property names that will trigger an Instance Refresh. A refresh will always be triggered by a change in any of `launch_configuration`, `launch_template`, or `mixed_instances_policy`.
 
 ~> **NOTE:** A refresh is started when any of the following Auto Scaling Group properties change: `launch_configuration`, `launch_template`, `mixed_instances_policy`. Additional properties can be specified in the `triggers` property of `instance_refresh`.