📝 Description

This pull request implements a new linode_database_postgresql_v2 resource supporting the new Aiven-backed managed database clusters.

Design Caveats

Flattened Fork Object

The fork block has been flattened into root-level fork_source and fork_restore_time attributes because:

1. HashiCorp recommends against making use of blocks in new (non-migrated) Framework resources.
   a. Additionally, treating it as a block would have inconsistent usage with the updates object.
2. When implemented as an ObjectAttribute, all sub-fields must be specified. Because restore_time is treated as optional and computed as an API, there is a valid case where the user does not want to specify it explicitly but does want to access the computed restore time.

Independent Pending Updates Set

The updates.pending set has been split into a root-level pending_updates set, which allows users to specify their updates configuration as a single object.

Flattened Hosts and Credentials Blocks

The hosts and credentials blocks have been flattened into root-level fields to simplify our implementation and to make unknown/null behavior a bit more predictable.

✔️ How to Test

The following test steps assume you have pulled down this PR locally and do not have your account configured for legacy DBaaS clusters.

Unit Testing

make unit-test

Integration Testing

make PKG_NAME=linode/databasepostgresqlv2 int-test

Manual Testing

1. In a terraform-provider-linode sandbox environment (e.g. dx-devenv), apply the following configuration:

 resource "linode_database_postgresql_v2" "test" {
  region = "us-mia"
  label = "tf-test"
  type = "g6-nanode-1"
  engine_id = "postgresql/16"

  allow_list = ["10.0.0.2/32", "10.0.0.3/32"]
  cluster_size = 3

  updates = {
    hour_of_day = 2
    day_of_week = 3
    frequency = "weekly"
    duration = 4
  }
}

NOTE: Database creations should take ~15 minutes.

2. Ensure the apply was successful and the database has been properly created in Cloud Manager.
3. Re-apply the configuration and ensure no changes are proposed.
4. Make arbitrary changes to the allow_list, cluster_size, type, and updates attributes.
5. Re-apply the configuration.
6. Ensure the apply was successful and the database has been properly updated in Cloud Manager.
7. Re-apply the configuration and ensure no changes are proposed.
8. Append the following to the end of your configuration to create a new database forked from the first database:

resource "linode_database_postgresql_v2" "forked" {
  region = "us-mia"
  label = "tf-test-forked"
  type = "g6-nanode-1"
  engine_id = "postgresql/16"

  source = linode_database_postgresql_v2.test.id
}

9. Re-apply the configuration and validate that a new forked database has been created in Cloud Manager.
10. Re-apply the configuration and ensure no changes are proposed.
11. Destroy the configuration and ensure all databases are deleted as expected.