v0.46.0

Ignore `engine_version` for rds instance in order to upgrade without recreating db instances @nitrocode (#115)

what

• Ignore engine_version for rds instance in order to upgrade

why

• When the engine_version for the aws_rds_cluster is changed and applied, the db instances will be upgraded.
• There is a note on the rds_cluster_instance#engine_version which states

  (Optional, Forces new resource) The database engine version. When managing the engine version in the cluster, it is recommended to add the lifecycle ignore_changes configuration for this argument to prevent Terraform from proposing changes to the instance engine version directly.

terraform plan

  # module.primary_aurora_postgres_cluster.aws_rds_cluster_instance.default[0] must be replaced
+/- resource "aws_rds_cluster_instance" "default" {
      + apply_immediately               = (known after apply)
      ~ arn                             = "arn:aws:rds:us-east-2:snip:db:snip-1" -> (known after apply)
      ~ availability_zone               = "us-east-2c" -> (known after apply)
      ~ ca_cert_identifier              = "rds-ca-2019" -> (known after apply)
      ~ dbi_resource_id                 = "db-snip" -> (known after apply)
      ~ endpoint                        = "snip-1.snip.us-east-2.rds.amazonaws.com" -> (known after apply)
      ~ engine_version                  = "12.4" -> "12.6" # forces replacement
      ~ id                              = "snip-1" -> (known after apply)
      + identifier_prefix               = (known after apply)
      ~ kms_key_id                      = "arn:aws:kms:us-east-2:snip:key/snip" -> (known after apply)
      + monitoring_role_arn             = (known after apply)
      + performance_insights_kms_key_id = (known after apply)
      ~ port                            = 5432 -> (known after apply)
      ~ preferred_backup_window         = "07:00-09:00" -> (known after apply)
      ~ preferred_maintenance_window    = "sun:07:32-sun:08:02" -> (known after apply)
      ~ storage_encrypted               = true -> (known after apply)
      ~ writer                          = true -> (known after apply)
        # (13 unchanged attributes hidden)
    }

terraform apply (error)

module.primary_aurora_postgres_cluster.aws_rds_cluster_instance.default[0]: Creating...
╷
│ Error: error creating RDS Cluster (snip) Instance: DBInstanceAlreadyExists: DB Instance already exists
│ 	status code: 400, request id: snip
│ 
│   with module.primary_aurora_postgres_cluster.aws_rds_cluster_instance.default[0],
│   on main.tf line 206, in resource "aws_rds_cluster_instance" "default":
│  206: resource "aws_rds_cluster_instance" "default" {
│ 
╵

terraform plan (no changes)

Note: Objects have changed outside of Terraform

Terraform detected the following changes made outside of Terraform since the last "terraform
apply":

  # module.primary_aurora_postgres_cluster.aws_rds_cluster_instance.default[0] has been changed
  ~ resource "aws_rds_cluster_instance" "default" {
      ~ engine_version               = "12.4" -> "12.6"
        id                           = "snip-1"
        # (24 unchanged attributes hidden)
    }

Unless you have made equivalent changes to your configuration, or ignored the relevant
attributes using ignore_changes, the following plan may include actions to undo or respond to
these changes.

No changes. Your infrastructure matches the configuration.

Confirmed in the AWS console that the postgres aurora rds instance and cluster are 12.6.

references

N/A