Add a CNAME recursive resolving datasource

docs/data-sources/recursive_cname_record_set.md

@@ -0,0 +1,36 @@
+---
+# generated by https://github.com/hashicorp/terraform-plugin-docs
+page_title: "dns_recursive_cname_record_set Data Source - terraform-provider-dns"
+subcategory: ""
+description: |-
+  Use this data source to get DNS CNAME record set of the host.
+---
+
+# dns_recursive_cname_record_set (Data Source)
+
+Use this data source to get DNS CNAME record set of the host.
+
+## Example Usage
+
+```terraform
+data "dns_recursive_cname_record_set" "hashicorp" {
+  host = "www.hashicorp.com"
+}
+
+output "hashi_cnames" {
+  value = data.dns_recursive_cname_record_set.hashicorp.cnames
+}
+```
+
+<!-- schema generated by tfplugindocs -->
+## Schema
+
+### Required
+
+- `host` (String) Host to recursively look up.
+
+### Read-Only
+
+- `cnames` (List of String) Chained CNAME records associated with host.
+- `id` (String) Always set to the host.
+- `last_cname` (String) The final CNAME at end of the chain.

examples/data-sources/dns_recursive_cname_record_set/data-source.tf

@@ -0,0 +1,7 @@
+data "dns_recursive_cname_record_set" "hashicorp" {
+  host = "www.hashicorp.com"
+}
+
+output "hashi_cnames" {
+  value = data.dns_recursive_cname_record_set.hashicorp.cnames
+}

internal/provider/data_dns_recursive_cname_record_set.go

@@ -0,0 +1,89 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package provider
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"strings"
+
+	"github.com/hashicorp/terraform-plugin-framework/datasource"
+	"github.com/hashicorp/terraform-plugin-framework/datasource/schema"
+	"github.com/hashicorp/terraform-plugin-framework/types"
+)
+
+var (
+	_ datasource.DataSource = (*dnsCNAMERecursiveRecordSetDataSource)(nil)
+)
+
+func NewDnsCNAMERecursiveRecordSetDataSource() datasource.DataSource {
+	return &dnsCNAMERecursiveRecordSetDataSource{}
+}
+
+type dnsCNAMERecursiveRecordSetDataSource struct{}
+
+func (d *dnsCNAMERecursiveRecordSetDataSource) Metadata(ctx context.Context, req datasource.MetadataRequest, resp *datasource.MetadataResponse) {
+	resp.TypeName = req.ProviderTypeName + "_recursive_cname_record_set"
+}
+
+func (d *dnsCNAMERecursiveRecordSetDataSource) Schema(ctx context.Context, req datasource.SchemaRequest, resp *datasource.SchemaResponse) {
+	resp.Schema = schema.Schema{
+		Description: "Use this data source to get DNS CNAME record set of the host.",
+		Attributes: map[string]schema.Attribute{
+			"host": schema.StringAttribute{
+				Required:    true,
+				Description: "Host to recursively look up.",
+			},
+			"cnames": schema.ListAttribute{
+				ElementType: types.StringType,
+				Computed:    true,
+				Description: "Chained CNAME records associated with host.",
+			},
+			"last_cname": schema.StringAttribute{
+				Computed:    true,
+				Description: "The final CNAME at end of the chain.",
+			},
+			"id": schema.StringAttribute{
+				Computed:    true,
+				Description: "Always set to the host.",
+			},
+		},
+	}
+}
+
+func (d *dnsCNAMERecursiveRecordSetDataSource) Read(ctx context.Context, req datasource.ReadRequest, resp *datasource.ReadResponse) {
+	var config cnameRecursiveRecordSetConfig
+
+	resp.Diagnostics.Append(req.Config.Get(ctx, &config)...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	cnames := []string{}
+
+	host := config.Host.ValueString()
+	for cname, err := net.LookupCNAME(host); cname != host; cname, err = net.LookupCNAME(host) {
+		if err != nil {
+			resp.Diagnostics.AddError(fmt.Sprintf("error looking up CNAME records for %q: ", host), err.Error())
+			return
+		}
+		cnames = append(cnames, strings.Clone(cname))
+		host = cname
+	}
+
+	config.CNAMES, _ = types.ListValueFrom(ctx, types.StringType, cnames)
+	if len(cnames) > 0 {
+		config.LastCNAME = types.StringValue(cnames[len(cnames)-1])
+	}
+	config.ID = config.Host
+	resp.Diagnostics.Append(resp.State.Set(ctx, config)...)
+}
+
+type cnameRecursiveRecordSetConfig struct {
+	ID        types.String `tfsdk:"id"`
+	Host      types.String `tfsdk:"host"`
+	CNAMES    types.List   `tfsdk:"cnames"`
+	LastCNAME types.String `tfsdk:"last_cname"`
+}

internal/provider/data_dns_recursive_cname_record_set_test.go

@@ -0,0 +1,59 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package provider
+
+import (
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
+)
+
+func TestAccDataDnsRecursiveCnameRecordSet_Basic(t *testing.T) {
+        recordName := "data.dns_recursive_cname_record_set.test"
+
+        resource.UnitTest(t, resource.TestCase{
+                ProtoV5ProviderFactories: testProtoV5ProviderFactories,
+                Steps: []resource.TestStep{
+                        {
+                                Config: `
+data "dns_recursive_cname_record_set" "test" {
+  host = "terraform-provider-dns-cname.hashicorptest.com"
+}
+`,
+                                Check: resource.ComposeAggregateTestCheckFunc(
+                                        resource.TestCheckResourceAttr(recordName, "cnames.0", "example.com."),
+                                        resource.TestCheckNoResourceAttr(recordName, "cnames.1"),
+                                        resource.TestCheckResourceAttr(recordName, "last_cname", "example.com."),
+                                        resource.TestCheckResourceAttr(recordName, "host", "terraform-provider-dns-cname.hashicorptest.com"),
+                                        resource.TestCheckResourceAttr(recordName, "id", "terraform-provider-dns-cname.hashicorptest.com"),
+                                ),
+                        },
+                },
+        })
+}
+
+func TestAccDataDnsRecursiveCnameRecordSet_Complex(t *testing.T) {
+	recordName := "data.dns_recursive_cname_record_set.test"
+
+	resource.UnitTest(t, resource.TestCase{
+		ProtoV5ProviderFactories: testProtoV5ProviderFactories,
+		Steps: []resource.TestStep{
+			{
+				Config: `
+data "dns_recursive_cname_record_set" "test" {
+  host = "test2.tony.docusign.dev"
+}
+`,
+				Check: resource.ComposeAggregateTestCheckFunc(
+					resource.TestCheckResourceAttr(recordName, "cnames.0", "stage.services.docusign.net."),
+					resource.TestCheckResourceAttr(recordName, "cnames.1", "stage.services.docusign.net.akadns.net."),
+					resource.TestCheckNoResourceAttr(recordName, "cnames.2"),
+					resource.TestCheckResourceAttr(recordName, "last_cname", "stage.services.docusign.net.akadns.net."),
+					resource.TestCheckResourceAttr(recordName, "host", "test2.tony.docusign.dev"),
+					resource.TestCheckResourceAttr(recordName, "id", "test2.tony.docusign.dev"),
+				),
+			},
+		},
+	})
+}

internal/provider/provider_framework.go

@@ -347,6 +347,7 @@ func (p *dnsProvider) DataSources(ctx context.Context) []func() datasource.DataS
 		NewDnsARecordSetDataSource,
 		NewDnsAAAARecordSetDataSource,
 		NewDnsCNAMERecordSetDataSource,
+		NewDnsCNAMERecursiveRecordSetDataSource,
 		NewDnsMXRecordSetDataSource,
 		NewDnsNSRecordSetDataSource,
 		NewDnsPTRRecordSetDataSource,