[breaking] aws-aurora-postgres: Disable auto minor version upgrade by…

… default. (#311)

* [Breaking] Disable auto minor version upgrade by default.

aws-aurora-postgres/README.md

@@ -55,14 +55,14 @@ No resources.
 | Name | Description | Type | Default | Required |
 |------|-------------|------|---------|:--------:|
 | <a name="input_apply_immediately"></a> [apply\_immediately](#input\_apply\_immediately) | If false changes will not be applied until next maintenance window. | `string` | `false` | no |
-| <a name="input_auto_minor_version_upgrade"></a> [auto\_minor\_version\_upgrade](#input\_auto\_minor\_version\_upgrade) | Set the databases to automatically upgrade minor versions. | `bool` | `true` | no |
+| <a name="input_auto_minor_version_upgrade"></a> [auto\_minor\_version\_upgrade](#input\_auto\_minor\_version\_upgrade) | Set the databases to automatically upgrade minor versions. WARNING - if this is enabled, make sure engine_version is set to a *prefix* rather that a specific version so that TF won't try to downgrade DB's that have been auto-upgraded. Docs: https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/db_instance#engine_version | `bool` | `false` | no |
 | <a name="input_ca_cert_identifier"></a> [ca\_cert\_identifier](#input\_ca\_cert\_identifier) | Identifier for the certificate authority. | `string` | `"rds-ca-2019"` | no |
 | <a name="input_database_name"></a> [database\_name](#input\_database\_name) | The name of the database to be created in the cluster. | `string` | n/a | yes |
 | <a name="input_database_password"></a> [database\_password](#input\_database\_password) | Password for user that will be created. | `string` | n/a | yes |
 | <a name="input_database_subnet_group"></a> [database\_subnet\_group](#input\_database\_subnet\_group) | The name of an existing database subnet group to use. | `string` | n/a | yes |
 | <a name="input_database_username"></a> [database\_username](#input\_database\_username) | Default user to be created. | `string` | n/a | yes |
 | <a name="input_db_parameters"></a> [db\_parameters](#input\_db\_parameters) | Instance params you can set. [Doc](https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraPostgreSQL.Reference.html#AuroraPostgreSQL.Reference.Parameters.Instance) | `list(any)` | `[]` | no |
-| <a name="input_engine_version"></a> [engine\_version](#input\_engine\_version) | The version of Postgres to use. | `string` | `"10"` | no |
+| <a name="input_engine_version"></a> [engine\_version](#input\_engine\_version) | The version of Postgres to use. This should be a *prefix* if auto version upgrades are enabled. (Docs: https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/db_instance#engine_version)| `string` | `"10"` | no |
 | <a name="input_env"></a> [env](#input\_env) | Env for tagging and naming. See [doc](../README.md#consistent-tagging). | `string` | n/a | yes |
 | <a name="input_iam_database_authentication_enabled"></a> [iam\_database\_authentication\_enabled](#input\_iam\_database\_authentication\_enabled) | n/a | `string` | `false` | no |
 | <a name="input_ingress_cidr_blocks"></a> [ingress\_cidr\_blocks](#input\_ingress\_cidr\_blocks) | A list of CIDR blocks that should be allowed to communicate with this Aurora cluster. | `list(string)` | `[]` | no |

aws-aurora-postgres/variables.tf

@@ -105,7 +105,7 @@ variable "kms_key_id" {
 
 variable "engine_version" {
   type        = string
-  description = "The version of Postgres to use."
+  description = "The version of Postgres to use. This should be a *prefix* if auto version upgrades are enabled. (Docs: https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/db_instance#engine_version)"
   default     = "10"
 }
 
@@ -127,6 +127,6 @@ variable "ca_cert_identifier" {
 
 variable "auto_minor_version_upgrade" {
   type        = bool
-  description = "Set the databases to automatically upgrade minor versions."
-  default     = true
+  description = "Set the databases to automatically upgrade minor versions. WARNING - if this is enabled, make sure engine_version is set to a *prefix* rather that a specific version so that TF won't try to downgrade DB's that have been auto-upgraded. Docs: https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/db_instance#engine_version"
+  default     = false
 }