r/aws_ecs_service: add triggers attribute to force update in-place

.changelog/25840.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+resource/aws_ecs_service: Add `triggers` argument to enable in-place updates (redeployments) on each apply, when used with `force_new_deployment = true`
+```

internal/service/ecs/service.go

@@ -340,6 +340,14 @@ func ResourceService() *schema.Resource {
 				Type:     schema.TypeString,
 				Optional: true,
 			},
+			// modeled after null_resource & aws_api_gateway_deployment
+			// only for _updates in-place_ rather than replacements
+			"triggers": {
+				Type:     schema.TypeMap,
+				Optional: true,
+				Computed: true,
+				Elem:     &schema.Schema{Type: schema.TypeString},
+			},
 			"wait_for_steady_state": {
 				Type:     schema.TypeBool,
 				Optional: true,
@@ -350,10 +358,34 @@ func ResourceService() *schema.Resource {
 		CustomizeDiff: customdiff.Sequence(
 			verify.SetTagsDiff,
 			capacityProviderStrategyCustomizeDiff,
+			triggersCustomizeDiff,
 		),
 	}
 }
 
+func triggersCustomizeDiff(_ context.Context, d *schema.ResourceDiff, meta interface{}) error {
+	// clears diff to avoid extraneous diffs but lets it pass for triggering update
+	fnd := false
+	if v, ok := d.GetOk("force_new_deployment"); ok {
+		fnd = v.(bool)
+	}
+
+	if d.HasChange("triggers") && !fnd {
+		return d.Clear("triggers")
+	}
+
+	if d.HasChange("triggers") && fnd {
+		o, n := d.GetChange("triggers")
+		if len(o.(map[string]interface{})) > 0 && len(n.(map[string]interface{})) == 0 {
+			return d.Clear("triggers")
+		}
+
+		return nil
+	}
+
+	return nil
+}
+
 func capacityProviderStrategyCustomizeDiff(_ context.Context, d *schema.ResourceDiff, meta interface{}) error {
 	// to be backward compatible, should ForceNew almost always (previous behavior), unless:
 	//   force_new_deployment is true and
@@ -642,6 +674,8 @@ func resourceServiceRead(d *schema.ResourceData, meta interface{}) error {
 	d.Set("platform_version", service.PlatformVersion)
 	d.Set("enable_execute_command", service.EnableExecuteCommand)
 
+	d.Set("triggers", d.Get("triggers"))
+
 	// Save cluster in the same format
 	if strings.HasPrefix(d.Get("cluster").(string), "arn:"+meta.(*conns.AWSClient).Partition+":ecs:") {
 		d.Set("cluster", service.ClusterArn)

internal/service/ecs/service_test.go

@@ -685,6 +685,42 @@ func TestAccECSService_forceNewDeployment(t *testing.T) {
 	})
 }
 
+func TestAccECSService_forceNewDeploymentTriggers(t *testing.T) {
+	var service1, service2 ecs.Service
+	rName := sdkacctest.RandomWithPrefix(acctest.ResourcePrefix)
+	resourceName := "aws_ecs_service.test"
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:                 func() { acctest.PreCheck(t) },
+		ErrorCheck:               acctest.ErrorCheck(t, ecs.EndpointsID),
+		ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories,
+		CheckDestroy:             testAccCheckServiceDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccServiceConfig_forceNewDeployment(rName),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckServiceExists(resourceName, &service1),
+					resource.TestCheckResourceAttr(resourceName, "ordered_placement_strategy.#", "1"),
+					resource.TestCheckResourceAttr(resourceName, "ordered_placement_strategy.0.type", "binpack"),
+					resource.TestCheckResourceAttr(resourceName, "ordered_placement_strategy.0.field", "memory"),
+				),
+			},
+			{
+				Config: testAccServiceConfig_forceNewDeploymentTriggers(rName),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckServiceExists(resourceName, &service2),
+					testAccCheckServiceNotRecreated(&service1, &service2),
+					resource.TestCheckResourceAttr(resourceName, "force_new_deployment", "true"),
+					resource.TestCheckResourceAttrSet(resourceName, "triggers.update"),
+					resource.TestCheckResourceAttr(resourceName, "ordered_placement_strategy.#", "1"),
+					resource.TestCheckResourceAttr(resourceName, "ordered_placement_strategy.0.type", "binpack"),
+					resource.TestCheckResourceAttr(resourceName, "ordered_placement_strategy.0.field", "memory"),
+				),
+			},
+		},
+	})
+}
+
 func TestAccECSService_PlacementStrategy_basic(t *testing.T) {
 	var service1, service2, service3, service4 ecs.Service
 	rName := sdkacctest.RandomWithPrefix(acctest.ResourcePrefix)
@@ -1941,6 +1977,47 @@ resource "aws_ecs_service" "test" {
 `, rName)
 }
 
+func testAccServiceConfig_forceNewDeploymentTriggers(rName string) string {
+	return fmt.Sprintf(`
+resource "aws_ecs_cluster" "default" {
+  name = %[1]q
+}
+
+resource "aws_ecs_task_definition" "test" {
+  family = %[1]q
+
+  container_definitions = <<DEFINITION
+[
+  {
+    "cpu": 128,
+    "essential": true,
+    "image": "mongo:latest",
+    "memory": 128,
+    "name": "mongodb"
+  }
+]
+DEFINITION
+}
+
+resource "aws_ecs_service" "test" {
+  cluster              = aws_ecs_cluster.default.id
+  desired_count        = 1
+  force_new_deployment = true
+  name                 = %[1]q
+  task_definition      = aws_ecs_task_definition.test.arn
+
+  ordered_placement_strategy {
+    type  = "binpack"
+    field = "memory"
+  }
+
+  triggers = {
+    update = timestamp()
+  }
+}
+`, rName)
+}
+
 func testAccServiceConfig_placementStrategy(rName string) string {
 	return fmt.Sprintf(`
 resource "aws_ecs_cluster" "default" {

website/docs/r/ecs_service.html.markdown

@@ -85,6 +85,22 @@ resource "aws_ecs_service" "example" {
 }
 ```
 
+### Redeploy Service On Every Apply
+
+The key used with `triggers` is arbitrary.
+
+```terraform
+resource "aws_ecs_service" "example" {
+  # ... other configurations ...
+
+  force_new_deployment = true
+
+  triggers = {
+    redeployment = timestamp()
+  }
+}
+```
+
 ## Argument Reference
 
 The following arguments are required:
@@ -116,6 +132,7 @@ The following arguments are optional:
 * `service_registries` - (Optional) Service discovery registries for the service. The maximum number of `service_registries` blocks is `1`. See below.
 * `tags` - (Optional) Key-value map of resource tags. If configured with a provider [`default_tags` configuration block](https://registry.terraform.io/providers/hashicorp/aws/latest/docs#default_tags-configuration-block) present, tags with matching keys will overwrite those defined at the provider-level.
 * `task_definition` - (Optional) Family and revision (`family:revision`) or full ARN of the task definition that you want to run in your service. Required unless using the `EXTERNAL` deployment controller. If a revision is not specified, the latest `ACTIVE` revision is used.
+* `triggers` - (Optional) Map of arbitrary keys and values that, when changed, will trigger an in-place update (redeployment). Useful with `timestamp()`. See example above.
 * `wait_for_steady_state` - (Optional) If `true`, Terraform will wait for the service to reach a steady state (like [`aws ecs wait services-stable`](https://docs.aws.amazon.com/cli/latest/reference/ecs/wait/services-stable.html)) before continuing. Default `false`.
 
 ### capacity_provider_strategy