Merge pull request #37174 from ponkio-o/fix-asg/warm_pool-max_group_p…

…repared_capacity

[ASG] fix: Fixed `max_group_prepared_capacity` to allow setting 0

.changelog/37174.txt

@@ -0,0 +1,7 @@
+```release-note:bug
+resource/aws_autoscaling_group: Fix bug updating `warm_pool.max_group_prepared_capacity` to `0`
+```
+
+```release-note:enhancement
+resource/aws_autoscaling_group: Add plan-time validation of `warm_pool.max_group_prepared_capacity` and `warm_pool.min_size`
+```

internal/service/autoscaling/group.go

@@ -923,14 +923,16 @@ func resourceGroup() *schema.Resource {
 							},
 						},
 						"max_group_prepared_capacity": {
-							Type:     schema.TypeInt,
-							Optional: true,
-							Default:  defaultWarmPoolMaxGroupPreparedCapacity,
+							Type:         schema.TypeInt,
+							Optional:     true,
+							Default:      defaultWarmPoolMaxGroupPreparedCapacity,
+							ValidateFunc: validation.IntAtLeast(defaultWarmPoolMaxGroupPreparedCapacity),
 						},
 						"min_size": {
-							Type:     schema.TypeInt,
-							Optional: true,
-							Default:  0,
+							Type:         schema.TypeInt,
+							Optional:     true,
+							Default:      0,
+							ValidateFunc: validation.IntAtLeast(0),
 						},
 						"pool_state": {
 							Type:             schema.TypeString,
@@ -3264,7 +3266,7 @@ func expandPutWarmPoolInput(name string, tfMap map[string]interface{}) *autoscal
 		apiObject.InstanceReusePolicy = expandInstanceReusePolicy(v[0].(map[string]interface{}))
 	}
 
-	if v, ok := tfMap["max_group_prepared_capacity"].(int); ok && v != 0 {
+	if v, ok := tfMap["max_group_prepared_capacity"].(int); ok {
 		apiObject.MaxGroupPreparedCapacity = aws.Int32(int32(v))
 	}
 

internal/service/autoscaling/group_test.go

@@ -1874,6 +1874,18 @@ func TestAccAutoScalingGroup_warmPool(t *testing.T) {
 					resource.TestCheckNoResourceAttr(resourceName, "warm_pool.#"),
 				),
 			},
+			{
+				Config: testAccGroupConfig_warmPoolZero(rName),
+				Check: resource.ComposeAggregateTestCheckFunc(
+					testAccCheckGroupExists(ctx, resourceName, &group),
+					resource.TestCheckResourceAttr(resourceName, "warm_pool.#", acctest.Ct1),
+					resource.TestCheckResourceAttr(resourceName, "warm_pool.0.instance_reuse_policy.#", acctest.Ct1),
+					resource.TestCheckResourceAttr(resourceName, "warm_pool.0.instance_reuse_policy.0.reuse_on_scale_in", acctest.CtTrue),
+					resource.TestCheckResourceAttr(resourceName, "warm_pool.0.max_group_prepared_capacity", acctest.Ct0),
+					resource.TestCheckResourceAttr(resourceName, "warm_pool.0.min_size", acctest.Ct0),
+					resource.TestCheckResourceAttr(resourceName, "warm_pool.0.pool_state", "Stopped"),
+				),
+			},
 		},
 	})
 }
@@ -5778,6 +5790,34 @@ resource "aws_autoscaling_group" "test" {
 `, rName))
 }
 
+func testAccGroupConfig_warmPoolZero(rName string) string {
+	return acctest.ConfigCompose(testAccGroupConfig_launchConfigurationBase(rName, "t3.nano"), fmt.Sprintf(`
+resource "aws_autoscaling_group" "test" {
+  availability_zones   = [data.aws_availability_zones.available.names[0]]
+  max_size             = 5
+  min_size             = 1
+  desired_capacity     = 1
+  name                 = %[1]q
+  launch_configuration = aws_launch_configuration.test.name
+
+  warm_pool {
+    pool_state                  = "Stopped"
+    min_size                    = 0
+    max_group_prepared_capacity = 0
+    instance_reuse_policy {
+      reuse_on_scale_in = true
+    }
+  }
+
+  tag {
+    key                 = "Name"
+    value               = %[1]q
+    propagate_at_launch = true
+  }
+}
+`, rName))
+}
+
 func testAccGroupConfig_warmPoolNone(rName string) string {
 	return acctest.ConfigCompose(testAccGroupConfig_launchConfigurationBase(rName, "t3.nano"), fmt.Sprintf(`
 resource "aws_autoscaling_group" "test" {