data/aws_vpc_ipam_preview_next_cidr

.changelog/22643.txt

@@ -0,0 +1,3 @@
+```release-note:new-data-source
+aws_vpc_ipam_preview_next_cidr
+```

internal/provider/provider.go

@@ -484,6 +484,7 @@ func Provider() *schema.Provider {
 			"aws_vpc_endpoint_service":                       ec2.DataSourceVPCEndpointService(),
 			"aws_vpc_endpoint":                               ec2.DataSourceVPCEndpoint(),
 			"aws_vpc_ipam_pool":                              ec2.DataSourceVPCIpamPool(),
+			"aws_vpc_ipam_preview_next_cidr":                 ec2.DataSourceVPCIpamPreviewNextCidr(),
 			"aws_vpc_peering_connection":                     ec2.DataSourceVPCPeeringConnection(),
 			"aws_vpc_peering_connections":                    ec2.DataSourceVPCPeeringConnections(),
 			"aws_vpc":                                        ec2.DataSourceVPC(),

internal/service/ec2/vpc_ipam_preview_next_cidr_data_source.go

@@ -0,0 +1,91 @@
+package ec2
+
+import (
+	"fmt"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/service/ec2"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/validation"
+	"github.com/hashicorp/terraform-provider-aws/internal/conns"
+	"github.com/hashicorp/terraform-provider-aws/internal/flex"
+	"github.com/hashicorp/terraform-provider-aws/internal/verify"
+)
+
+func DataSourceVPCIpamPreviewNextCidr() *schema.Resource {
+	return &schema.Resource{
+		Read: dataSourceVPCIpamPreviewNextCidrRead,
+
+		Schema: map[string]*schema.Schema{
+			"cidr": {
+				Type:     schema.TypeString,
+				Computed: true,
+			},
+			"disallowed_cidrs": {
+				Type:     schema.TypeSet,
+				Optional: true,
+				Elem: &schema.Schema{
+					Type: schema.TypeString,
+					ValidateFunc: validation.Any(
+						verify.ValidIPv4CIDRNetworkAddress,
+						// Follow the numbers used for netmask_length
+						validation.IsCIDRNetwork(0, 32),
+					),
+				},
+			},
+			"ipam_pool_id": {
+				Type:     schema.TypeString,
+				Required: true,
+			},
+			"netmask_length": {
+				// Possible netmask lengths for IPv4 addresses are 0 - 32.
+				// AllocateIpamPoolCidr API
+				//   - If there is no DefaultNetmaskLength allocation rule set on the pool,
+				//   you must specify either the NetmaskLength or the CIDR.
+				//   - If the DefaultNetmaskLength allocation rule is set on the pool,
+				//   you can specify either the NetmaskLength or the CIDR and the
+				//   DefaultNetmaskLength allocation rule will be ignored.
+				Type:         schema.TypeInt,
+				Optional:     true,
+				ValidateFunc: validation.IntBetween(0, 32),
+			},
+		},
+	}
+}
+
+func dataSourceVPCIpamPreviewNextCidrRead(d *schema.ResourceData, meta interface{}) error {
+	conn := meta.(*conns.AWSClient).EC2Conn
+	poolId := d.Get("ipam_pool_id").(string)
+
+	input := &ec2.AllocateIpamPoolCidrInput{
+		ClientToken:     aws.String(resource.UniqueId()),
+		IpamPoolId:      aws.String(poolId),
+		PreviewNextCidr: aws.Bool(true),
+	}
+
+	if v, ok := d.GetOk("disallowed_cidrs"); ok && v.(*schema.Set).Len() > 0 {
+		input.DisallowedCidrs = flex.ExpandStringSet(v.(*schema.Set))
+	}
+
+	if v, ok := d.GetOk("netmask_length"); ok {
+		input.NetmaskLength = aws.Int64(int64(v.(int)))
+	}
+
+	output, err := conn.AllocateIpamPoolCidr(input)
+
+	if err != nil {
+		return fmt.Errorf("Error previewing next cidr from IPAM pool (%s): %w", d.Get("ipam_pool_id").(string), err)
+	}
+
+	if output == nil || output.IpamPoolAllocation == nil {
+		return fmt.Errorf("error previewing next cidr from ipam pool (%s): empty response", poolId)
+	}
+
+	cidr := output.IpamPoolAllocation.Cidr
+
+	d.Set("cidr", cidr)
+	d.SetId(encodeVPCIpamPreviewNextCidrID(aws.StringValue(cidr), poolId))
+
+	return nil
+}

internal/service/ec2/vpc_ipam_preview_next_cidr_data_source_test.go

@@ -0,0 +1,168 @@
+package ec2_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/aws/aws-sdk-go/service/ec2"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
+	"github.com/hashicorp/terraform-provider-aws/internal/acctest"
+)
+
+func TestAccDataSourceVPCIpamPreviewNextCidr_ipv4Basic(t *testing.T) {
+	datasourceName := "data.aws_vpc_ipam_preview_next_cidr.test"
+	netmaskLength := "28"
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:     func() { acctest.PreCheck(t); testAccIPAMPreCheck(t) },
+		ErrorCheck:   acctest.ErrorCheck(t, ec2.EndpointsID),
+		Providers:    acctest.Providers,
+		CheckDestroy: nil,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccDataSourceVPCIpamPreviewNextCidrIpv4Basic(netmaskLength),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttrSet(datasourceName, "cidr"),
+					resource.TestCheckResourceAttrPair(datasourceName, "ipam_pool_id", "aws_vpc_ipam_pool.test", "id"),
+					resource.TestCheckResourceAttr(datasourceName, "netmask_length", netmaskLength),
+				),
+			},
+		},
+	})
+}
+
+func TestAccDataSourceVPCIpamPreviewNextCidr_ipv4Allocated(t *testing.T) {
+	datasourceName := "data.aws_vpc_ipam_preview_next_cidr.test"
+	netmaskLength := "28"
+	allocatedCidr := "172.2.0.0/28"
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:     func() { acctest.PreCheck(t); testAccIPAMPreCheck(t) },
+		ErrorCheck:   acctest.ErrorCheck(t, ec2.EndpointsID),
+		Providers:    acctest.Providers,
+		CheckDestroy: nil,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccDataSourceVPCIpamPreviewNextCidrIpv4Basic(netmaskLength),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttr(datasourceName, "cidr", allocatedCidr),
+					resource.TestCheckResourceAttrPair(datasourceName, "ipam_pool_id", "aws_vpc_ipam_pool.test", "id"),
+					resource.TestCheckResourceAttr(datasourceName, "netmask_length", netmaskLength),
+				),
+			},
+			{
+				Config: testAccDataSourceVPCIpamPreviewNextCidrIpv4Allocated(netmaskLength),
+				Check: resource.ComposeTestCheckFunc(
+					// cidr should not change even after allocation
+					resource.TestCheckResourceAttr(datasourceName, "cidr", allocatedCidr),
+					resource.TestCheckResourceAttrPair(datasourceName, "ipam_pool_id", "aws_vpc_ipam_pool.test", "id"),
+					resource.TestCheckResourceAttr(datasourceName, "netmask_length", netmaskLength),
+				),
+			},
+		},
+	})
+}
+
+func TestAccDataSourceVPCIpamPreviewNextCidr_ipv4DisallowedCidr(t *testing.T) {
+	datasourceName := "data.aws_vpc_ipam_preview_next_cidr.test"
+	disallowedCidr := "172.2.0.0/28"
+	netmaskLength := "28"
+	expectedCidr := "172.2.0.16/28"
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:     func() { acctest.PreCheck(t); testAccIPAMPreCheck(t) },
+		ErrorCheck:   acctest.ErrorCheck(t, ec2.EndpointsID),
+		Providers:    acctest.Providers,
+		CheckDestroy: nil,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccDataSourceVPCIpamPreviewNextCidrIpv4DisallowedCidr(netmaskLength, disallowedCidr),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttr(datasourceName, "cidr", expectedCidr),
+					resource.TestCheckResourceAttr(datasourceName, "disallowed_cidrs.#", "1"),
+					resource.TestCheckResourceAttr(datasourceName, "disallowed_cidrs.0", disallowedCidr),
+					resource.TestCheckResourceAttrPair(datasourceName, "ipam_pool_id", "aws_vpc_ipam_pool.test", "id"),
+					resource.TestCheckResourceAttr(datasourceName, "netmask_length", netmaskLength),
+				),
+			},
+		},
+	})
+}
+
+const testAccDataSourceVPCIpamPreviewNextCidrIpv4Base = `
+data "aws_region" "current" {}
+
+resource "aws_vpc_ipam" "test" {
+  description = "test"
+  operating_regions {
+    region_name = data.aws_region.current.name
+  }
+}
+
+resource "aws_vpc_ipam_pool" "test" {
+  address_family = "ipv4"
+  ipam_scope_id  = aws_vpc_ipam.test.private_default_scope_id
+  locale         = data.aws_region.current.name
+}
+
+resource "aws_vpc_ipam_pool_cidr" "test" {
+  ipam_pool_id = aws_vpc_ipam_pool.test.id
+  cidr         = "172.2.0.0/24"
+}
+`
+
+func testAccDataSourceVPCIpamPreviewNextCidrIpv4Basic(netmaskLength string) string {
+	return acctest.ConfigCompose(
+		testAccDataSourceVPCIpamPreviewNextCidrIpv4Base,
+		fmt.Sprintf(`
+data "aws_vpc_ipam_preview_next_cidr" "test" {
+  ipam_pool_id   = aws_vpc_ipam_pool.test.id
+  netmask_length = %[1]q
+
+  depends_on = [
+    aws_vpc_ipam_pool_cidr.test
+  ]
+}
+`, netmaskLength))
+}
+
+func testAccDataSourceVPCIpamPreviewNextCidrIpv4Allocated(netmaskLength string) string {
+	return acctest.ConfigCompose(
+		testAccDataSourceVPCIpamPreviewNextCidrIpv4Base,
+		fmt.Sprintf(`
+data "aws_vpc_ipam_preview_next_cidr" "test" {
+  ipam_pool_id   = aws_vpc_ipam_pool.test.id
+  netmask_length = %[1]q
+
+  depends_on = [
+    aws_vpc_ipam_pool_cidr.test
+  ]
+}
+
+resource "aws_vpc_ipam_pool_cidr_allocation" "test" {
+  ipam_pool_id = aws_vpc_ipam_pool.test.id
+  cidr         = data.aws_vpc_ipam_preview_next_cidr.test.cidr
+
+  lifecycle {
+    ignore_changes = [cidr]
+  }
+}
+`, netmaskLength))
+}
+
+func testAccDataSourceVPCIpamPreviewNextCidrIpv4DisallowedCidr(netmaskLength, disallowedCidr string) string {
+	return testAccDataSourceVPCIpamPreviewNextCidrIpv4Base + fmt.Sprintf(`
+data "aws_vpc_ipam_preview_next_cidr" "test" {
+  ipam_pool_id   = aws_vpc_ipam_pool.test.id
+  netmask_length = %[1]q
+
+  disallowed_cidrs = [
+    %[2]q
+  ]
+
+  depends_on = [
+    aws_vpc_ipam_pool_cidr.test
+  ]
+}
+`, netmaskLength, disallowedCidr)
+}

website/docs/d/vpc_ipam_preview_next_cidr.html.markdown

@@ -0,0 +1,52 @@
+---
+subcategory: "VPC"
+layout: "aws"
+page_title: "AWS: aws_vpc_ipam_preview_next_cidr"
+description: |-
+  Previews a CIDR from an IPAM address pool.
+---
+
+# Data Source: aws_vpc_ipam_preview_next_cidr
+
+Previews a CIDR from an IPAM address pool. Only works for private IPv4.
+
+~> **NOTE:** This functionality is also encapsulated in a resource sharing the same name. The data source can be used when you need to use the cidr in a calculation of the same Root module, `count` for example. However, once a cidr range has been allocated that was previewed, the next refresh will find a **new** cidr and may force new resources downstream. Make sure to use Terraform's lifecycle `ignore_changes` policy if this is undesirable.
+
+## Example Usage
+
+Basic usage:
+
+```terraform
+data "aws_vpc_ipam_preview_next_cidr" "test" {
+  ipam_pool_id   = aws_vpc_ipam_pool.test.id
+  netmask_length = 28
+
+  depends_on = [
+    aws_vpc_ipam_pool_cidr.test
+  ]
+}
+
+resource "aws_vpc_ipam_pool_cidr_allocation" "test" {
+  ipam_pool_id = aws_vpc_ipam_pool.test.id
+  cidr         = data.aws_vpc_ipam_preview_next_cidr.test.cidr
+
+  lifecycle {
+    ignore_changes = [cidr]
+  }
+}
+```
+
+## Argument Reference
+
+The following arguments are supported:
+
+* `disallowed_cidrs` - (Optional) Exclude a particular CIDR range from being returned by the pool.
+* `ipam_pool_id` - (Required) The ID of the pool to which you want to assign a CIDR.
+* `netmask_length` - (Optional) The netmask length of the CIDR you would like to preview from the IPAM pool.
+
+## Attributes Reference
+
+In addition to all arguments above, the following attributes are exported:
+
+* `cidr` - The previewed CIDR from the pool.
+* `id` - The ID of the preview.