r/aws_instance: Set new computed value for public_dns and `public_i…

…p` attributes when changing `instance_type`, `user_data`, or `user_data_base64`.

.changelog/#####.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+resource/aws_instance: Set new computed value for `public_dns` and `public_ip` attributes when changing `instance_type`, `user_data`, or `user_data_base64`
+```

internal/acctest/statecheck/expect_not_known_value.go

@@ -0,0 +1,48 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package statecheck
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/hashicorp/terraform-plugin-testing/knownvalue"
+	"github.com/hashicorp/terraform-plugin-testing/statecheck"
+	"github.com/hashicorp/terraform-plugin-testing/tfjsonpath"
+)
+
+type expectNotKnownValueCheck struct {
+	base          Base
+	attributePath tfjsonpath.Path
+	notValue      knownvalue.Check
+}
+
+func (e expectNotKnownValueCheck) CheckState(ctx context.Context, request statecheck.CheckStateRequest, response *statecheck.CheckStateResponse) {
+	resource, ok := e.base.ResourceFromState(request, response)
+	if !ok {
+		return
+	}
+
+	value, err := tfjsonpath.Traverse(resource.AttributeValues, e.attributePath)
+	if err != nil {
+		response.Error = err
+
+		return
+	}
+
+	err = e.notValue.CheckValue(value)
+	if err == nil {
+		response.Error = fmt.Errorf("value for attribute at path: %s.%s is %v", resource.Address, e.attributePath.String(), value)
+
+		return
+	}
+}
+
+func ExpectNotKnownValue(resourceAddress string, attributePath tfjsonpath.Path, notValue knownvalue.Check) statecheck.StateCheck {
+	return expectNotKnownValueCheck{
+		base:          NewBase(resourceAddress),
+		attributePath: attributePath,
+		notValue:      notValue,
+	}
+}

internal/service/ec2/ec2_instance.go

@@ -900,12 +900,24 @@ func resourceInstance() *schema.Resource {
 
 				return nil
 			},
-			customdiff.ComputedIf("launch_template.0.id", func(_ context.Context, diff *schema.ResourceDiff, meta interface{}) bool {
-				return diff.HasChange("launch_template.0.name")
-			}),
 			customdiff.ComputedIf("launch_template.0.name", func(_ context.Context, diff *schema.ResourceDiff, meta interface{}) bool {
 				return diff.HasChange("launch_template.0.id")
 			}),
+			customdiff.ComputedIf("launch_template.0.id", func(_ context.Context, diff *schema.ResourceDiff, meta interface{}) bool {
+				return diff.HasChange("launch_template.0.name")
+			}),
+			func(ctx context.Context, diff *schema.ResourceDiff, meta interface{}) error {
+				// Set public_dns and public_ip to newly computed if the instance will be stopped and started
+				// as part of Update and there is already a public_ip value in state.
+				if diff.Id() != "" && diff.HasChanges(names.AttrInstanceType, "user_data", "user_data_base64") {
+					if diff.Get("public_ip").(string) != "" {
+						diff.SetNewComputed("public_dns")
+						diff.SetNewComputed("public_ip")
+					}
+				}
+
+				return nil
+			},
 			customdiff.ForceNewIf("user_data", func(_ context.Context, diff *schema.ResourceDiff, meta interface{}) bool {
 				return diff.Get("user_data_replace_on_change").(bool)
 			}),
@@ -1821,6 +1833,7 @@ func resourceInstanceUpdate(ctx context.Context, d *schema.ResourceData, meta in
 		}
 	}
 
+	// See also CustomizeDiff.
 	if d.HasChanges(names.AttrInstanceType, "user_data", "user_data_base64") && !d.IsNewResource() {
 		// For each argument change, we start and stop the instance
 		// to account for behaviors occurring outside terraform.

internal/service/ec2/ec2_instance_data_source_test.go

@@ -1029,7 +1029,7 @@ data "aws_instance" "test" {
 func testAccInstanceDataSourceConfig_privateIP(rName string) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLatestAmazonLinux2HVMEBSX8664AMI(),
-		testAccInstanceVPCConfig(rName, false, 1),
+		testAccInstanceConfig_vpcBase(rName, false, 1),
 		fmt.Sprintf(`
 resource "aws_instance" "test" {
   ami           = data.aws_ami.amzn2-ami-minimal-hvm-ebs-x86_64.id
@@ -1051,7 +1051,7 @@ data "aws_instance" "test" {
 func testAccInstanceDataSourceConfig_secondaryPrivateIPs(rName string) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLatestAmazonLinux2HVMEBSX8664AMI(),
-		testAccInstanceVPCConfig(rName, false, 1),
+		testAccInstanceConfig_vpcBase(rName, false, 1),
 		fmt.Sprintf(`
 resource "aws_instance" "test" {
   ami                   = data.aws_ami.amzn2-ami-minimal-hvm-ebs-x86_64.id
@@ -1073,7 +1073,7 @@ data "aws_instance" "test" {
 func testAccInstanceDataSourceConfig_ipv6Addresses(rName string) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLatestAmazonLinux2HVMEBSX8664AMI(),
-		testAccInstanceVPCIPv6Config(rName),
+		testAccInstanceConfig_vpcIPv6Base(rName),
 		fmt.Sprintf(`
 resource "aws_instance" "test" {
   ami                = data.aws_ami.amzn2-ami-minimal-hvm-ebs-x86_64.id
@@ -1126,7 +1126,7 @@ data "aws_instance" "test" {
 func testAccInstanceDataSourceConfig_vpc(rName string) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLatestAmazonLinux2HVMEBSX8664AMI(),
-		testAccInstanceVPCConfig(rName, false, 1),
+		testAccInstanceConfig_vpcBase(rName, false, 1),
 		fmt.Sprintf(`
 resource "aws_instance" "test" {
   ami                         = data.aws_ami.amzn2-ami-minimal-hvm-ebs-x86_64.id
@@ -1151,7 +1151,7 @@ data "aws_instance" "test" {
 func testAccInstanceDataSourceConfig_placementGroup(rName string) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLatestAmazonLinux2HVMEBSX8664AMI(),
-		testAccInstanceVPCConfig(rName, false, 1),
+		testAccInstanceConfig_vpcBase(rName, false, 1),
 		fmt.Sprintf(`
 resource "aws_placement_group" "test" {
   name     = %[1]q
@@ -1216,8 +1216,8 @@ data "aws_instance" "test" {
 
 func testAccInstanceDataSourceConfig_vpcSecurityGroups(rName string) string {
 	return acctest.ConfigCompose(acctest.ConfigLatestAmazonLinux2HVMEBSX8664AMI(),
-		testAccInstanceVPCConfig(rName, false, 1),
-		testAccInstanceVPCSecurityGroupConfig(rName),
+		testAccInstanceConfig_vpcBase(rName, false, 1),
+		testAccInstanceConfig_vpcSecurityGroupBase(rName),
 		fmt.Sprintf(`
 resource "aws_instance" "test" {
   ami                    = data.aws_ami.amzn2-ami-minimal-hvm-ebs-x86_64.id
@@ -1265,7 +1265,7 @@ data "aws_instance" "test" {
 func testAccInstanceDataSourceConfig_getUser(rName string, getUserData bool) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLatestAmazonLinux2HVMEBSX8664AMI(),
-		testAccInstanceVPCConfig(rName, false, 1),
+		testAccInstanceConfig_vpcBase(rName, false, 1),
 		fmt.Sprintf(`
 resource "aws_instance" "test" {
   ami           = data.aws_ami.amzn2-ami-minimal-hvm-ebs-x86_64.id
@@ -1293,7 +1293,7 @@ data "aws_instance" "test" {
 func testAccInstanceDataSourceConfig_getUserNoUser(rName string, getUserData bool) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLatestAmazonLinux2HVMEBSX8664AMI(),
-		testAccInstanceVPCConfig(rName, false, 1),
+		testAccInstanceConfig_vpcBase(rName, false, 1),
 		fmt.Sprintf(`
 resource "aws_instance" "test" {
   ami           = data.aws_ami.amzn2-ami-minimal-hvm-ebs-x86_64.id
@@ -1315,7 +1315,7 @@ data "aws_instance" "test" {
 func testAccInstanceDataSourceConfig_autoRecovery(rName string, val string) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLatestAmazonLinux2HVMEBSX8664AMI(),
-		testAccInstanceVPCConfig(rName, false, 1),
+		testAccInstanceConfig_vpcBase(rName, false, 1),
 		fmt.Sprintf(`
 resource "aws_instance" "test" {
   ami           = data.aws_ami.amzn2-ami-minimal-hvm-ebs-x86_64.id
@@ -1340,7 +1340,7 @@ data "aws_instance" "test" {
 func testAccInstanceDataSourceConfig_creditSpecification(rName string) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLatestAmazonLinux2HVMEBSX8664AMI(),
-		testAccInstanceVPCConfig(rName, false, 1),
+		testAccInstanceConfig_vpcBase(rName, false, 1),
 		fmt.Sprintf(`
 resource "aws_instance" "test" {
   ami           = data.aws_ami.amzn2-ami-minimal-hvm-ebs-x86_64.id
@@ -1365,7 +1365,7 @@ data "aws_instance" "test" {
 func testAccInstanceDataSourceConfig_metaOptions(rName string) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLatestAmazonLinux2HVMEBSX8664AMI(),
-		testAccInstanceVPCConfig(rName, false, 0),
+		testAccInstanceConfig_vpcBase(rName, false, 0),
 		acctest.AvailableEC2InstanceTypeForRegion("t3.micro", "t2.micro"),
 		fmt.Sprintf(`
 resource "aws_instance" "test" {
@@ -1394,7 +1394,7 @@ data "aws_instance" "test" {
 func testAccInstanceDataSourceConfig_enclaveOptions(rName string) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLatestAmazonLinux2HVMEBSX8664AMI(),
-		testAccInstanceVPCConfig(rName, false, 0),
+		testAccInstanceConfig_vpcBase(rName, false, 0),
 		acctest.AvailableEC2InstanceTypeForRegion("c5a.xlarge", "c5.xlarge"),
 		fmt.Sprintf(`
 resource "aws_instance" "test" {
@@ -1457,7 +1457,7 @@ data "aws_instance" "test" {
 func testAccInstanceDataSourceConfig_disableAPIStopTermination(rName string, disableApiStopTermination bool) string {
 	return acctest.ConfigCompose(
 		acctest.ConfigLatestAmazonLinux2HVMEBSX8664AMI(),
-		testAccInstanceVPCConfig(rName, false, 1),
+		testAccInstanceConfig_vpcBase(rName, false, 1),
 		fmt.Sprintf(`
 resource "aws_instance" "test" {
   ami                     = data.aws_ami.amzn2-ami-minimal-hvm-ebs-x86_64.id