opentelekomcloud_rds_instance_v3 - restoring to original instance deletes instance incl. backups and ends in instance creation loop

[reiSh6phoo9o]

Terraform provider version

provider registry.terraform.io/opentelekomcloud/opentelekomcloud v1.35.3

Affected Resource(s)

• opentelekomcloud_rds_instance_v3

Terraform Configuration Files

resource "opentelekomcloud_rds_instance_v3" "main" {
  name                   = "test-rds"
  availability_zone = var.availability_zone

  db {
    password = random_password.main.result
    type         = var.db_type
    version    = var.db_version
    port         = local.db_port
  }

  security_group_id = opentelekomcloud_networking_secgroup_v2.main.id
  subnet_id              = data.opentelekomcloud_vpc_subnet_v1.private.id
  vpc_id                   = data.opentelekomcloud_vpc_v1.default.id
  flavor                     = var.flavor

  volume {
    type              = var.volume_type
    size               = var.volume_size_gb
  }
 
  # add this only after the instance has been created:
  restore_point {
    instance_id = "<id of this instance>"
    backup_id   = "<id of automated backup of this instance>"
  }
}

Steps to Reproduce

1. terraform apply without restore_point block -> creates the instance
2. terraform apply with additional restore_point block

Expected Behavior

From docs here: https://docs.otc.t-systems.com/relational-database-service/umn/working_with_rds_for_mysql/backups_and_restorations/restoring_from_backup_files_to_db_instances.html#procedure , I assume that I can restore to the original instance.
From docs here: https://registry.terraform.io/providers/opentelekomcloud/opentelekomcloud/latest/docs/resources/rds_instance_v3#restore_point , I can not see any constraints.

When adding a restore_point block to an existing opentelekomcloud_rds_instance_v3, I expect this to trigger a "Restore to Original". That is, it should not destroy the original instance, nor delete all automated backups.

Alternativly, the provider docs should clearly document, that:

• adding a restore_point block triggers instance replacment, thus deleting automated backups
• thus its not possible to restore to original instance using terraform
• thus this block basically is only useful on instance creation

Actual Behavior

tf apply triggers an instance replacement, thus:

• deletes the original instance
• deletes all automated backups associated with that instance
• provisions a new instance and tries to apply the backup on it
• this leads to a loop, the web console shows: "Single task exception. The system is trying again."
• propably because the backup it tries to apply is deleted in the previous step
• so finally, my original database and all associated backus are gone, and I'm stuck in an instance creation loop

[anton-sidelnikov]

Hello @reiSh6phoo9o, no, you do all procedure wrong, please read documentation carefully. Yes you can restore RDS but it must be another RDS instance.
If you apply

  restore_point {
    instance_id = "<id of this instance>"
    backup_id   = "<id of automated backup of this instance>"
  }

to existing one, so now you know the result.

From documentation:

If you point existing instance it will become unavailable

Never use terraform with auto-approve key, terraform always informs you about force recreation, it always means that resource will be destroyed.

[reiSh6phoo9o]

Hi @anton-sidelnikov ,

thanks for looking into this.

From what you tell, and what I found out myself, I agree, that it is not possible to restore to the same instance (aka "restore to original", as it is called in otc docs) using terraform.

I disagree, that the documentation tells anything about it. Docs list three methods for restoration: restore to original, restore to existing, restore to new. The screenshot you took documents the "restore to existing", which refers to : restoring to another, already existing rds.

The method "restore to original" is documented like that:

From this, and from my experience using OTC webconsole, it is clearly possible and supported to restore a running RDS to an earlier point in time, without replacing the instance.

The thing I ask, is two things:

First, feature request: would love to see, that I can restore a RDS to a earlier point in time, as I can do using the webconsole.

Second: if that's not possible: would love to see some hints in the provider documentation, that the method "restore to original" is not possible using terraform.

Thanks!

[anton-sidelnikov]

Hi @reiSh6phoo9o, yes I agree, we will update documentation first, then will think how to implement another options for restoration, currently from provider you can only restore to another instance.

[artem-lifshits]

@reiSh6phoo9o feature added and documentation updated.