Add user_data_replace_on_change field to aws_instance

.changelog/23604.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+resource/aws_instance: Add `user_data_replace_on_change` attribute
+```

internal/service/ec2/instance.go

@@ -600,6 +600,11 @@ func ResourceInstance() *schema.Resource {
 					return
 				},
 			},
+			"user_data_replace_on_change": {
+				Type:	 schema.TypeBool,
+				Optional: true,
+				Default: false,
+			},
 			"volume_tags": tftags.TagsSchema(),
 			"vpc_security_group_ids": {
 				Type:     schema.TypeSet,
@@ -695,6 +700,14 @@ func ResourceInstance() *schema.Resource {
 			customdiff.ComputedIf("launch_template.0.name", func(_ context.Context, diff *schema.ResourceDiff, meta interface{}) bool {
 				return diff.HasChange("launch_template.0.id")
 			}),
+			customdiff.ForceNewIf("user_data", func(_ context.Context, diff *schema.ResourceDiff, meta interface{}) bool {
+				replace := diff.Get("user_data_replace_on_change")
+				return replace.(bool)
+			}),
+			customdiff.ForceNewIf("user_data_base64", func(_ context.Context, diff *schema.ResourceDiff, meta interface{}) bool {
+				replace := diff.Get("user_data_replace_on_change")
+				return replace.(bool)
+			}),
 		),
 	}
 }

internal/service/ec2/instance_test.go

@@ -3749,6 +3749,87 @@ func TestAccEC2Instance_UserData_unspecifiedToEmptyString(t *testing.T) {
 	})
 }
 
+func TestAccEC2Instance_UserData_replaceOnChangeFlag(t *testing.T) {
+	var v ec2.Instance
+	resourceName := "aws_instance.test"
+	rName := fmt.Sprintf("tf-testacc-instance-%s", sdkacctest.RandString(12))
+
+	var instanceId string
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:     func() { acctest.PreCheck(t) },
+		ErrorCheck:   acctest.ErrorCheck(t, ec2.EndpointsID),
+		Providers:    acctest.Providers,
+		CheckDestroy: testAccCheckInstanceDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccInstanceConfig_UserData_Specified_With_Replace_Flag_On(rName, "TestData1"),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckInstanceExists(resourceName, &v),
+					testResourceIdHasChanged(resourceName, &instanceId),
+				),
+			},
+			{
+				ResourceName:            resourceName,
+				ImportState:             true,
+				ImportStateVerify:       true,
+			},
+			// Switching should force a recreate
+			{
+				Config:             testAccInstanceConfig_UserData_Specified_With_Replace_Flag_On(rName, "TestData2"),
+				Check:              resource.ComposeTestCheckFunc(
+					testAccCheckInstanceExists(resourceName, &v),
+					testResourceIdHasChanged(resourceName, &instanceId),
+				),
+				ExpectNonEmptyPlan: true,
+				PlanOnly:           true,
+			},
+		},
+	})
+}
+
+func TestAccEC2Instance_UserDataBase64_replaceOnChangeFlag(t *testing.T) {
+	var v ec2.Instance
+	resourceName := "aws_instance.test"
+	rName := fmt.Sprintf("tf-testacc-instance-%s", sdkacctest.RandString(12))
+
+	var instanceId string
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:     func() { acctest.PreCheck(t) },
+		ErrorCheck:   acctest.ErrorCheck(t, ec2.EndpointsID),
+		Providers:    acctest.Providers,
+		CheckDestroy: testAccCheckInstanceDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccInstanceConfig_UserData64_Specified_With_Replace_Flag_On(rName, "3dc39dda39be1205215e776bad998da361a5955d"),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckInstanceExists(resourceName, &v),
+					testResourceIdHasChanged(resourceName, &instanceId),
+				),
+
+			},
+			{
+				ResourceName:            resourceName,
+				ImportState:             true,
+				ImportStateVerify:       true,
+			},
+			// Switching should force a recreate
+			{
+				Config:             testAccInstanceConfig_UserData64_Specified_With_Replace_Flag_On(rName, "3dc39dda39be1205215e776bad998da361a5955e"),
+				Check:              resource.ComposeTestCheckFunc(
+					testAccCheckInstanceExists(resourceName, &v),
+					testResourceIdHasChanged(resourceName, &instanceId),
+				),
+				ExpectNonEmptyPlan: true,
+				PlanOnly:           true,
+			},
+		},
+	})
+}
+
+
+
 func TestAccEC2Instance_hibernation(t *testing.T) {
 	var instance1, instance2 ec2.Instance
 	resourceName := "aws_instance.test"
@@ -4142,6 +4223,21 @@ func testAccCheckInstanceExistsWithProvider(n string, i *ec2.Instance, providerF
 	}
 }
 
+func testResourceIdHasChanged (resourceName string, instanceId *string) resource.TestCheckFunc {
+	return func(s *terraform.State) error {
+		instance := s.RootModule().Resources[resourceName]
+		if(*instanceId == "") {
+			*instanceId = instance.Primary.ID
+			return nil
+		}
+		if(*instanceId != instance.Primary.ID){
+			return nil
+		} else {
+			return fmt.Errorf("A new instance should have been created")
+		}
+	}
+}
+
 func testAccCheckStopInstance(instance *ec2.Instance) resource.TestCheckFunc {
 	return func(s *terraform.State) error {
 		conn := acctest.Provider.Meta().(*conns.AWSClient).EC2Conn
@@ -6501,6 +6597,36 @@ resource "aws_instance" "test" {
 `)
 }
 
+func testAccInstanceConfig_UserData_Specified_With_Replace_Flag_On(rName string, userData string) string {
+	return acctest.ConfigCompose(
+		acctest.ConfigLatestAmazonLinuxHvmEbsAmi(),
+		testAccInstanceVPCConfig(rName, false),
+		fmt.Sprintf(`
+resource "aws_instance" "test" {
+	ami           			  = data.aws_ami.amzn-ami-minimal-hvm-ebs.id
+	instance_type 			  = "t2.micro"
+	subnet_id     			  = aws_subnet.test.id
+	user_data     			  = "%[1]q"
+	user_data_replace_on_change = true
+	}
+`, userData))
+}
+
+func testAccInstanceConfig_UserData64_Specified_With_Replace_Flag_On(rName string, userData string) string {
+	return acctest.ConfigCompose(
+		acctest.ConfigLatestAmazonLinuxHvmEbsAmi(),
+		testAccInstanceVPCConfig(rName, false),
+		fmt.Sprintf(`
+resource "aws_instance" "test" {
+  ami           			  = data.aws_ami.amzn-ami-minimal-hvm-ebs.id
+  instance_type 			  = "t2.micro"
+  subnet_id     			  = aws_subnet.test.id
+  user_data_base64     		  = base64encode(%[1]q)
+  user_data_replace_on_change = true
+}
+`, userData))
+}
+
 // testAccInstanceVPCConfig returns the configuration for tests that create
 //   1) a VPC without IPv6 support
 //   2) a subnet in the VPC that optionally assigns public IP addresses to ENIs

website/docs/r/instance.html.markdown

@@ -132,8 +132,9 @@ The following arguments are supported:
 * `subnet_id` - (Optional) VPC Subnet ID to launch in.
 * `tags` - (Optional) A map of tags to assign to the resource. Note that these tags apply to the instance and not block storage devices. If configured with a provider [`default_tags` configuration block](/docs/providers/aws/index.html#default_tags-configuration-block) present, tags with matching keys will overwrite those defined at the provider-level.
 * `tenancy` - (Optional) Tenancy of the instance (if the instance is running in a VPC). An instance with a tenancy of dedicated runs on single-tenant hardware. The host tenancy is not supported for the import-instance command.
-* `user_data` - (Optional) User data to provide when launching the instance. Do not pass gzip-compressed data via this argument; see `user_data_base64` instead. Updates to this field will trigger a stop/start of the EC2 instance.
-* `user_data_base64` - (Optional) Can be used instead of `user_data` to pass base64-encoded binary data directly. Use this instead of `user_data` whenever the value is not a valid UTF-8 string. For example, gzip-encoded user data must be base64-encoded and passed via this argument to avoid corruption. Updates to this field will trigger a stop/start of the EC2 instance.
+* `user_data` - (Optional) User data to provide when launching the instance. Do not pass gzip-compressed data via this argument; see `user_data_base64` instead. Updates to this field will trigger a stop/start of the EC2 instance by default. If the `user_data_replace_on_change` is set then updates to this field will trigger a destroy and recreate.
+* `user_data_base64` - (Optional) Can be used instead of `user_data` to pass base64-encoded binary data directly. Use this instead of `user_data` whenever the value is not a valid UTF-8 string. For example, gzip-encoded user data must be base64-encoded and passed via this argument to avoid corruption. Updates to this field will trigger a stop/start of the EC2 instance by default. If the `user_data_replace_on_change` is set then updates to this field will trigger a destroy and recreate.
+* `user_data_replace_on_change` - (Optional) When used in combination with `user_data` or `user_data_base64` will trigger a destroy and recreate when set to `true`. Defaults to `false` if not set.
 * `volume_tags` - (Optional) A map of tags to assign, at instance-creation time, to root and EBS volumes.
 
 ~> **NOTE:** Do not use `volume_tags` if you plan to manage block device tags outside the `aws_instance` configuration, such as using `tags` in an [`aws_ebs_volume`](/docs/providers/aws/r/ebs_volume.html) resource attached via [`aws_volume_attachment`](/docs/providers/aws/r/volume_attachment.html). Doing so will result in resource cycling and inconsistent behavior.