r/aws_rds_cluster_instance: fix destroy error when cluster instance is in a read replica

.changelog/40409.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+resource/aws_rds_cluster_instance: Fix error when destroying from a read replica cluster
+```

internal/service/rds/cluster_instance.go

@@ -129,6 +129,11 @@ func resourceClusterInstance() *schema.Resource {
 				Type:     schema.TypeString,
 				Computed: true,
 			},
+			names.AttrForceDestroy: {
+				Type:     schema.TypeBool,
+				Optional: true,
+				Default:  false,
+			},
 			names.AttrIdentifier: {
 				Type:          schema.TypeString,
 				Optional:      true,
@@ -543,6 +548,21 @@ func resourceClusterInstanceDelete(ctx context.Context, d *schema.ResourceData,
 		},
 		"Delete the replica cluster before deleting")
 
+	if errs.IsAErrorMessageContains[*types.InvalidDBClusterStateFault](err, "Cannot delete the last instance of the read replica DB cluster") && d.Get(names.AttrForceDestroy).(bool) {
+		_, err = conn.PromoteReadReplicaDBCluster(ctx, &rds.PromoteReadReplicaDBClusterInput{
+			DBClusterIdentifier: aws.String(d.Get(names.AttrClusterIdentifier).(string)),
+		})
+		if err != nil {
+			return sdkdiag.AppendErrorf(diags, "promoting read replica to primary for RDS Cluster (%s): %s", d.Id(), err)
+		}
+
+		if _, err := waitDBClusterAvailable(ctx, conn, d.Id(), false, d.Timeout(schema.TimeoutDelete)); err != nil {
+			return sdkdiag.AppendErrorf(diags, "waiting for RDS Cluster (%s) update: %s", d.Id(), err)
+		}
+
+		_, err = conn.DeleteDBInstance(ctx, input)
+	}
+
 	if errs.IsA[*types.DBInstanceNotFoundFault](err) {
 		return diags
 	}

internal/service/rds/cluster_instance_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/aws/aws-sdk-go-v2/service/rds"
 	"github.com/aws/aws-sdk-go-v2/service/rds/types"
 	"github.com/hashicorp/aws-sdk-go-base/v2/tfawserr"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
 	sdkacctest "github.com/hashicorp/terraform-plugin-testing/helper/acctest"
 	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
 	"github.com/hashicorp/terraform-plugin-testing/terraform"
@@ -65,6 +66,7 @@ func TestAccRDSClusterInstance_basic(t *testing.T) {
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 			{
@@ -136,6 +138,7 @@ func TestAccRDSClusterInstance_identifierGenerated(t *testing.T) {
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 		},
@@ -172,6 +175,7 @@ func TestAccRDSClusterInstance_identifierPrefix(t *testing.T) {
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 		},
@@ -208,6 +212,7 @@ func TestAccRDSClusterInstance_tags(t *testing.T) {
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 			{
@@ -303,6 +308,7 @@ func TestAccRDSClusterInstance_az(t *testing.T) {
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 		},
@@ -339,6 +345,7 @@ func TestAccRDSClusterInstance_kmsKey(t *testing.T) {
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 		},
@@ -374,6 +381,7 @@ func TestAccRDSClusterInstance_publiclyAccessible(t *testing.T) {
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 			{
@@ -389,6 +397,7 @@ func TestAccRDSClusterInstance_publiclyAccessible(t *testing.T) {
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 			{
@@ -431,6 +440,7 @@ func TestAccRDSClusterInstance_copyTagsToSnapshot(t *testing.T) {
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 			{
@@ -474,6 +484,7 @@ func TestAccRDSClusterInstance_caCertificateIdentifier(t *testing.T) {
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 		},
@@ -509,6 +520,7 @@ func TestAccRDSClusterInstance_monitoringInterval(t *testing.T) {
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 			{
@@ -566,6 +578,7 @@ func TestAccRDSClusterInstance_MonitoringRoleARN_enabledToDisabled(t *testing.T)
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 			{
@@ -609,6 +622,7 @@ func TestAccRDSClusterInstance_MonitoringRoleARN_enabledToRemoved(t *testing.T)
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 			{
@@ -650,6 +664,7 @@ func TestAccRDSClusterInstance_MonitoringRoleARN_removedToEnabled(t *testing.T)
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 			{
@@ -693,6 +708,7 @@ func TestAccRDSClusterInstance_PerformanceInsightsEnabled_auroraMySQL1(t *testin
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 		},
@@ -729,6 +745,7 @@ func TestAccRDSClusterInstance_PerformanceInsightsEnabled_auroraPostgresql(t *te
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 		},
@@ -767,6 +784,7 @@ func TestAccRDSClusterInstance_PerformanceInsightsKMSKeyID_auroraMySQL1(t *testi
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 		},
@@ -803,6 +821,7 @@ func TestAccRDSClusterInstance_PerformanceInsightsKMSKeyIDAuroraMySQL1_defaultKe
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 			{
@@ -846,6 +865,7 @@ func TestAccRDSClusterInstance_performanceInsightsRetentionPeriod(t *testing.T)
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 			{
@@ -900,6 +920,7 @@ func TestAccRDSClusterInstance_PerformanceInsightsKMSKeyID_auroraPostgresql(t *t
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 		},
@@ -936,6 +957,7 @@ func TestAccRDSClusterInstance_PerformanceInsightsKMSKeyIDAuroraPostgresql_defau
 				ImportStateVerify: true,
 				ImportStateVerifyIgnore: []string{
 					names.AttrApplyImmediately,
+					names.AttrForceDestroy,
 				},
 			},
 			{
@@ -946,6 +968,88 @@ func TestAccRDSClusterInstance_PerformanceInsightsKMSKeyIDAuroraPostgresql_defau
 	})
 }
 
+func TestAccRDSClusterInstance_Replica_basic(t *testing.T) {
+	ctx := acctest.Context(t)
+	if testing.Short() {
+		t.Skip("skipping long-running test in short mode")
+	}
+
+	var primaryInstance types.DBInstance
+	var replicaInstance types.DBInstance
+	resourceName := "aws_rds_cluster_instance.test"
+	resourceName2 := "aws_rds_cluster_instance.alternate"
+	rName := sdkacctest.RandomWithPrefix(acctest.ResourcePrefix)
+
+	// record the initialized providers so that we can use them to
+	// check for the cluster in each region
+	var providers []*schema.Provider
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck: func() {
+			acctest.PreCheck(ctx, t)
+			acctest.PreCheckMultipleRegion(t, 2)
+		},
+		ErrorCheck:               acctest.ErrorCheck(t, names.RDSServiceID),
+		ProtoV5ProviderFactories: acctest.ProtoV5FactoriesPlusProvidersAlternate(ctx, t, &providers),
+		CheckDestroy:             acctest.CheckWithProviders(testAccCheckClusterInstanceDestroyWithProvider(ctx), &providers),
+		Steps: []resource.TestStep{
+			{
+				Config: testAccClusterInstanceConfig_replicationSource_basic(rName),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckClusterInstanceExistsWithProvider(ctx, resourceName, &primaryInstance, acctest.RegionProviderFunc(ctx, acctest.Region(), &providers)),
+					testAccCheckClusterInstanceExistsWithProvider(ctx, resourceName2, &replicaInstance, acctest.RegionProviderFunc(ctx, acctest.AlternateRegion(), &providers)),
+				),
+			},
+		},
+	})
+}
+
+func testAccCheckClusterInstanceExistsWithProvider(ctx context.Context, n string, v *types.DBInstance, providerF func() *schema.Provider) resource.TestCheckFunc {
+	return func(s *terraform.State) error {
+		rs, ok := s.RootModule().Resources[n]
+		if !ok {
+			return fmt.Errorf("Not found: %s", n)
+		}
+
+		conn := providerF().Meta().(*conns.AWSClient).RDSClient(ctx)
+
+		output, err := tfrds.FindDBInstanceByID(ctx, conn, rs.Primary.ID)
+		if err != nil {
+			return err
+		}
+
+		*v = *output
+
+		return nil
+	}
+}
+
+func testAccCheckClusterInstanceDestroyWithProvider(ctx context.Context) acctest.TestCheckWithProviderFunc {
+	return func(s *terraform.State, provider *schema.Provider) error {
+		conn := provider.Meta().(*conns.AWSClient).RDSClient(ctx)
+
+		for _, rs := range s.RootModule().Resources {
+			if rs.Type != "aws_rds_cluster_instance" {
+				continue
+			}
+
+			_, err := tfrds.FindDBInstanceByID(ctx, conn, rs.Primary.ID)
+
+			if tfresource.NotFound(err) {
+				continue
+			}
+
+			if err != nil {
+				return err
+			}
+
+			return fmt.Errorf("RDS Cluster Instance %s still exists", rs.Primary.ID)
+		}
+
+		return nil
+	}
+}
+
 func testAccPerformanceInsightsDefaultVersionPreCheck(ctx context.Context, t *testing.T, engine string) {
 	conn := acctest.Provider.Meta().(*conns.AWSClient).RDSClient(ctx)
 
@@ -1545,6 +1649,41 @@ resource "aws_rds_cluster_instance" "test" {
 `, rName))
 }
 
+func testAccClusterInstanceConfig_replicationSource_basic(rName string) string {
+	return acctest.ConfigCompose(
+		testAccClusterConfig_replicationSource_base(rName),
+		fmt.Sprintf(`
+resource "aws_rds_cluster" "alternate" {
+  provider = "awsalternate"
+
+  cluster_identifier            = "%[1]s-replica"
+  db_subnet_group_name          = aws_db_subnet_group.test.name
+  engine                        = %[2]q
+  kms_key_id                    = aws_kms_key.test.arn
+  storage_encrypted             = true
+  skip_final_snapshot           = true
+  replication_source_identifier = aws_rds_cluster.test.arn
+  source_region                 = data.aws_region.current.name
+
+  depends_on = [
+    aws_rds_cluster_instance.test,
+  ]
+}
+
+resource "aws_rds_cluster_instance" "alternate" {
+  provider = "awsalternate"
+
+  identifier         = "%[1]s-replica"
+  cluster_identifier = aws_rds_cluster.alternate.id
+  instance_class     = data.aws_rds_orderable_db_instance.test.instance_class
+  engine             = aws_rds_cluster.alternate.engine
+  engine_version     = aws_rds_cluster.alternate.engine_version
+
+  force_destroy = true
+}
+`, rName, tfrds.ClusterEngineAuroraMySQL))
+}
+
 func testAccClusterInstanceConfig_performanceInsightsEnabledAuroraPostgresql(rName, engine string) string {
 	return acctest.ConfigCompose(
 		testAccClusterInstanceConfig_orderableEngineBase(engine, true),

website/docs/r/rds_cluster_instance.html.markdown

@@ -65,6 +65,7 @@ This resource supports the following arguments:
 * `engine_version` - (Optional) Database engine version. Please note that to upgrade the `engine_version` of the instance, it must be done on the `aws_rds_cluster` `engine_version`. Trying to upgrade in `aws_cluster_instance` will not update the `engine_version`.
 * `engine` - (Required, Forces new resource) Name of the database engine to be used for the RDS cluster instance.
   Valid Values: `aurora-mysql`, `aurora-postgresql`, `mysql`, `postgres`.(Note that `mysql` and `postgres` are Multi-AZ RDS clusters).
+* `force_destroy` - (Optional) Forces an instance to be destroyed when a part of a read replica cluster. **Note:** will promote the read replica to a standalone cluster before instance deletion.
 * `identifier_prefix` - (Optional, Forces new resource) Creates a unique identifier beginning with the specified prefix. Conflicts with `identifier`.
 * `identifier` - (Optional, Forces new resource) Identifier for the RDS instance, if omitted, Terraform will assign a random, unique identifier.
 * `instance_class` - (Required) Instance class to use. For details on CPU and memory, see [Scaling Aurora DB Instances][4]. Aurora uses `db.*` instance classes/types. Please see [AWS Documentation][7] for currently available instance classes and complete details. For Aurora Serverless v2 use `db.serverless`.