feature: [New Data Source]: AWS Organizations descendant OUs

internal/service/organizations/organizational_units_descendant_organization_units_data_source.go

@@ -0,0 +1,96 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package organizations
+
+import (
+	"context"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/service/organizations"
+	awstypes "github.com/aws/aws-sdk-go-v2/service/organizations/types"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/diag"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
+	"github.com/hashicorp/terraform-provider-aws/internal/conns"
+	"github.com/hashicorp/terraform-provider-aws/internal/errs/sdkdiag"
+	"github.com/hashicorp/terraform-provider-aws/names"
+)
+
+// @SDKDataSource("aws_organizations_organizational_unit_descendant_organization_units", name="Organizational Unit Descendant Organization Units")
+func dataSourceOrganizationalUnitDescendantOrganizationUnits() *schema.Resource {
+	return &schema.Resource{
+		ReadWithoutTimeout: dataSourceOrganizationalUnitDescendantOrganizationUnitsRead,
+
+		Schema: map[string]*schema.Schema{
+			"children": {
+				Type:     schema.TypeList,
+				Computed: true,
+				Elem: &schema.Resource{
+					Schema: map[string]*schema.Schema{
+						names.AttrARN: {
+							Type:     schema.TypeString,
+							Computed: true,
+						},
+						names.AttrID: {
+							Type:     schema.TypeString,
+							Computed: true,
+						},
+						names.AttrName: {
+							Type:     schema.TypeString,
+							Computed: true,
+						},
+					},
+				},
+			},
+			"parent_id": {
+				Type:     schema.TypeString,
+				Required: true,
+			},
+		},
+	}
+}
+
+func dataSourceOrganizationalUnitDescendantOrganizationUnitsRead(ctx context.Context, d *schema.ResourceData, meta interface{}) diag.Diagnostics {
+	var diags diag.Diagnostics
+	conn := meta.(*conns.AWSClient).OrganizationsClient(ctx)
+
+	parentID := d.Get("parent_id").(string)
+	organizationUnits, err := findAllOrganizationUnitsForParentAndBelow(ctx, conn, parentID)
+
+	if err != nil {
+		return sdkdiag.AppendErrorf(diags, "listing Organizations Units for parent (%s) and descendants: %s", parentID, err)
+	}
+
+	d.SetId(parentID)
+
+	if err := d.Set("accounts", flattenOrganizationalUnits(organizationUnits)); err != nil {
+		return sdkdiag.AppendErrorf(diags, "setting organization units: %s", err)
+	}
+
+	return diags
+}
+
+// findAllOrganizationUnitsForParentAndBelow recurses down an OU tree, returning all organization units at the specified parent and below.
+func findAllOrganizationUnitsForParentAndBelow(ctx context.Context, conn *organizations.Client, id string) ([]awstypes.OrganizationalUnit, error) {
+	var output []awstypes.OrganizationalUnit
+
+	ous, err := findOrganizationalUnitsForParentByID(ctx, conn, id)
+
+	if err != nil {
+		return nil, err
+	}
+
+	output = append(output, ous...)
+
+	for _, ou := range ous {
+		organizationUnits, err := findAllOrganizationUnitsForParentAndBelow(ctx, conn, aws.ToString(ou.Id))
+
+		if err != nil {
+			return nil, err
+		}
+
+		output = append(output, organizationUnits...)
+	}
+
+	return output, nil
+}

internal/service/organizations/organizational_units_descendant_organization_units_data_source_test.go

@@ -0,0 +1,73 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package organizations_test
+
+import (
+	"fmt"
+	"testing"
+
+	sdkacctest "github.com/hashicorp/terraform-plugin-testing/helper/acctest"
+	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
+	"github.com/hashicorp/terraform-provider-aws/internal/acctest"
+	"github.com/hashicorp/terraform-provider-aws/names"
+)
+
+func testOrganizationalUnitDescendantOusDataSource_basic(t *testing.T) {
+	ctx := acctest.Context(t)
+	rName := sdkacctest.RandomWithPrefix(acctest.ResourcePrefix)
+	topOUDataSourceName := "data.aws_organizations_organizational_unit_descendant_organization_units.current"
+	newOU1DataSourceName := "data.aws_organizations_organizational_unit_descendant_organization_units.test0"
+	newOU2DataSourceName := "data.aws_organizations_organizational_unit_descendant_organization_units.test1"
+
+	resource.Test(t, resource.TestCase{
+		PreCheck: func() {
+			acctest.PreCheck(ctx, t)
+			acctest.PreCheckOrganizationManagementAccount(ctx, t)
+		},
+		ErrorCheck:               acctest.ErrorCheck(t, names.OrganizationsServiceID),
+		ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories,
+		Steps: []resource.TestStep{
+			{
+				Config: testOrganizationalUnitDescendantOusDataSourceConfig_basic(rName),
+				Check: resource.ComposeTestCheckFunc(
+					acctest.CheckResourceAttrGreaterThanValue(topOUDataSourceName, "children.#", 0),
+					resource.TestCheckResourceAttr(newOU1DataSourceName, "children.#", acctest.Ct0),
+					resource.TestCheckResourceAttr(newOU2DataSourceName, "children.#", acctest.Ct0),
+				),
+			},
+		},
+	})
+}
+
+func testOrganizationalUnitDescendantOusDataSourceConfig_basic(rName string) string {
+	return fmt.Sprintf(`
+data "aws_organizations_organization" "current" {}
+
+resource "aws_organizations_organizational_unit" "test0" {
+  name      = "%[1]s-0"
+  parent_id = data.aws_organizations_organization.current.roots[0].id
+}
+
+resource "aws_organizations_organizational_unit" "test1" {
+  name      = "%[1]s-1"
+  parent_id = aws_organizations_organizational_unit.test0.id
+}
+
+data "aws_organizations_organizational_unit_descendant_organization_units" "current" {
+  parent_id = data.aws_organizations_organization.current.roots[0].id
+
+  depends_on = [aws_organizations_organizational_unit.test0, aws_organizations_organizational_unit.test1]
+}
+
+data "aws_organizations_organizational_unit_descendant_organization_units" "test0" {
+  parent_id = aws_organizations_organizational_unit.test0.id
+
+  depends_on = [aws_organizations_organizational_unit.test1]
+}
+
+data "aws_organizations_organizational_unit_descendant_organization_units" "test1" {
+  parent_id = aws_organizations_organizational_unit.test1.id
+}
+`, rName)
+}

internal/service/organizations/organizations_test.go

@@ -50,6 +50,7 @@ func TestAccOrganizations_serial(t *testing.T) {
 			"update":                             testAccOrganizationalUnit_update,
 			"tags":                               testAccOrganizationalUnit_tags,
 			"DataSource_basic":                   testAccOrganizationalUnitDataSource_basic,
+			"DescendantOusDataSource_basic":      testOrganizationalUnitDescendantOusDataSource_basic,
 			"ChildAccountsDataSource_basic":      testAccOrganizationalUnitChildAccountsDataSource_basic,
 			"DescendantAccountsDataSource_basic": testAccOrganizationalUnitDescendantAccountsDataSource_basic,
 			"PluralDataSource_basic":             testAccOrganizationalUnitsDataSource_basic,

website/docs/d/organizations_organizational_unit_descendant_organization_units.html.markdown

@@ -0,0 +1,35 @@
+---
+subcategory: "Organizations"
+layout: "aws"
+page_title: "AWS: aws_organizations_organizational_unit_descendant_organization_units"
+description: |-
+  Get all direct child organizational units under a parent organizational unit. This provides all children.
+---
+
+# Data Source: aws_organizations_organizational_unit_descendant_organization_units
+
+Get all direct child organizational units under a parent organizational unit. This provides all children.
+
+## Example Usage
+
+```terraform
+data "aws_organizations_organization" "org" {}
+
+data "aws_organizations_organizational_unit_descendant_organization_units" "ous" {
+  parent_id = data.aws_organizations_organization.org.roots[0].id
+}
+```
+
+## Argument Reference
+
+* `parent_id` - (Required) Parent ID of the organizational unit.
+
+## Attribute Reference
+
+This data source exports the following attributes in addition to the arguments above:
+
+* `children` - List of child organizational units, which have the following attributes:
+  * `arn` - ARN of the organizational unit
+  * `name` - Name of the organizational unit
+  * `id` - ID of the organizational unit
+* `id` - Parent identifier of the organizational units.