[Enhancement] aws_vpclattice_service_network_vpc_association: Add private_dns_enabled and dns_options arguments for private DNS

[tabito-hara]

Rollback Plan

If a change needs to be reverted, we will publish an updated version of the library.

Changes to Security Controls

Are there any changes to security controls (access controls, encryption, logging) in this pull request? If so, explain.

Description

This PR adds the private_dns_enabled and dns_options arguments to the aws_vpclattice_service_network_vpc_association resource.

AWS API Behavior and Provider Implementation

• dns_options can be specified only when private_dns_enabled is set to true.
  • The expander and flattener for dns_options are invoked only when private_dns_enabled is true.
• dns_options.private_dns_specified_domains can be specified only when dns_options.private_dns_preference is set to either VERIFIED_DOMAINS_AND_SPECIFIED_DOMAINS or SPECIFIED_DOMAINS_ONLY.
  • The expander for private_dns_specified_domains is invoked only when dns_options.private_dns_preference has one of these values.
• Even when dns_options.private_dns_specified_domains is not specified in the configuration, the AWS API returns this value as ["*"] when dns_options.private_dns_preference is VERIFIED_DOMAINS_ONLY or ALL_DOMAINS.
  • Therefore, dns_options.private_dns_specified_domains is marked as Computed.
• private_dns_enabled (Boolean) is marked as Computed to avoid diffs when running terraform plan against existing resources.

Relations

Closes #45602

References

https://docs.aws.amazon.com/vpc-lattice/latest/APIReference/API_CreateServiceNetworkVpcAssociation.html#vpclattice-CreateServiceNetworkVpcAssociation-request-dnsOptions

Output from Acceptance Testing

$ make testacc TESTS='TestAccVPCLatticeServiceNetworkVPCAssociation_' PKG=vpclattice
make: Verifying source code with gofmt...
==> Checking that code complies with gofmt requirements...
make: Running acceptance tests on branch: 🌿 f-aws_vpclattice_service_network_vpc_association-add_private_dns 🌿...
TF_ACC=1 go1.24.11 test ./internal/service/vpclattice/... -v -count 1 -parallel 20 -run='TestAccVPCLatticeServiceNetworkVPCAssociation_'  -timeout 360m -vet=off
2025/12/17 09:54:58 Creating Terraform AWS Provider (SDKv2-style)...
2025/12/17 09:54:58 Initializing Terraform AWS Provider (SDKv2-style)...
=== RUN   TestAccVPCLatticeServiceNetworkVPCAssociation_basic
=== PAUSE TestAccVPCLatticeServiceNetworkVPCAssociation_basic
=== RUN   TestAccVPCLatticeServiceNetworkVPCAssociation_arn
=== PAUSE TestAccVPCLatticeServiceNetworkVPCAssociation_arn
=== RUN   TestAccVPCLatticeServiceNetworkVPCAssociation_disappears
=== PAUSE TestAccVPCLatticeServiceNetworkVPCAssociation_disappears
=== RUN   TestAccVPCLatticeServiceNetworkVPCAssociation_full
=== PAUSE TestAccVPCLatticeServiceNetworkVPCAssociation_full
=== RUN   TestAccVPCLatticeServiceNetworkVPCAssociation_privateDNS
=== PAUSE TestAccVPCLatticeServiceNetworkVPCAssociation_privateDNS
=== RUN   TestAccVPCLatticeServiceNetworkVPCAssociation_tags
=== PAUSE TestAccVPCLatticeServiceNetworkVPCAssociation_tags
=== CONT  TestAccVPCLatticeServiceNetworkVPCAssociation_basic
=== CONT  TestAccVPCLatticeServiceNetworkVPCAssociation_full
=== CONT  TestAccVPCLatticeServiceNetworkVPCAssociation_tags
=== CONT  TestAccVPCLatticeServiceNetworkVPCAssociation_disappears
=== CONT  TestAccVPCLatticeServiceNetworkVPCAssociation_privateDNS
=== CONT  TestAccVPCLatticeServiceNetworkVPCAssociation_arn
--- PASS: TestAccVPCLatticeServiceNetworkVPCAssociation_basic (168.49s)
--- PASS: TestAccVPCLatticeServiceNetworkVPCAssociation_arn (192.92s)
--- PASS: TestAccVPCLatticeServiceNetworkVPCAssociation_tags (201.76s)
--- PASS: TestAccVPCLatticeServiceNetworkVPCAssociation_disappears (245.59s)
--- PASS: TestAccVPCLatticeServiceNetworkVPCAssociation_full (256.35s)
--- PASS: TestAccVPCLatticeServiceNetworkVPCAssociation_privateDNS (673.64s)
PASS
ok      github.com/hashicorp/terraform-provider-aws/internal/service/vpclattice 677.900s

[github-actions]

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