Fix/ensure-only-central-backup-is-used (#49)

README.md

@@ -53,8 +53,6 @@ Terraform module for AWS RDS instances
 | <a name="input_apply_immediately"></a> [apply\_immediately](#input\_apply\_immediately) | Specifies whether any database modifications are applied immediately, or during the next maintenance window | `bool` | `false` | no |
 | <a name="input_auto_minor_version_upgrade"></a> [auto\_minor\_version\_upgrade](#input\_auto\_minor\_version\_upgrade) | Indicates that minor engine upgrades will be applied automatically to the DB instance during the maintenance window | `bool` | `true` | no |
 | <a name="input_availability_zone"></a> [availability\_zone](#input\_availability\_zone) | The Availability Zone of the RDS instance | `string` | `null` | no |
-| <a name="input_backup_retention_period"></a> [backup\_retention\_period](#input\_backup\_retention\_period) | The days to retain backups for | `number` | `null` | no |
-| <a name="input_backup_window"></a> [backup\_window](#input\_backup\_window) | The daily time range (in UTC) during which automated backups are created if they are enabled. Example: '09:46-10:16'. Must not overlap with maintenance\_window | `string` | `null` | no |
 | <a name="input_blue_green_update"></a> [blue\_green\_update](#input\_blue\_green\_update) | Enables low-downtime updates using RDS Blue/Green deployments. | `map(string)` | `{}` | no |
 | <a name="input_ca_cert_identifier"></a> [ca\_cert\_identifier](#input\_ca\_cert\_identifier) | Specifies the identifier of the CA certificate for the DB instance | `string` | `null` | no |
 | <a name="input_character_set_name"></a> [character\_set\_name](#input\_character\_set\_name) | The character set name to use for DB encoding in Oracle instances. This can't be changed. See Oracle Character Sets Supported in Amazon RDS and Collations and Character Sets for Microsoft SQL Server for more information. This can only be set on creation | `string` | `null` | no |

locals.tf

@@ -113,7 +113,8 @@ locals {
   performance_insights_enabled          = var.performance_insights_enabled != null ? var.performance_insights_enabled : local.default_config.performance_insights_enabled
   performance_insights_retention_period = var.performance_insights_retention_period != null ? var.performance_insights_retention_period : local.default_config.performance_insights_retention_period
   delete_automated_backups              = var.delete_automated_backups != null ? var.delete_automated_backups : local.default_config.delete_automated_backups
-  backup_retention_period               = var.backup_retention_period != null ? var.backup_retention_period : 0
+  backup_retention_period               = null
+  backup_window                         = null
 
   ########################################################################
   # Tagging

main.tf

@@ -108,7 +108,7 @@ module "db_instance" {
   performance_insights_enabled          = local.performance_insights_enabled
   performance_insights_retention_period = local.performance_insights_retention_period
   backup_retention_period               = local.backup_retention_period
-  backup_window                         = var.backup_window
+  backup_window                         = local.backup_window
   monitoring_interval                   = var.enhanced_monitoring_interval
   monitoring_role_arn                   = local.monitoring_role_arn
   timeouts                              = var.timeouts

variables.tf

@@ -273,6 +273,10 @@ variable "maintenance_window" { # TODO: Need validation. Use regex?
   description = "The window to perform maintenance in. Syntax: 'ddd:hh24:mi-ddd:hh24:mi'. Eg: 'Mon:00:00-Mon:03:00'"
   type        = string
   default     = "Sat:18:00-Sat:20:00" # This is adjusted in accordance with AWS Backup schedule, see info here: https://wiki.dfds.cloud/en/playbooks/aws-backup/aws-backup-getting-started
+  validation {
+    condition     = can(regex("^([a-zA-Z]{3}):([0-2][0-9]):([0-5][0-9])-([a-zA-Z]{3}):([0-2][0-9]):([0-5][0-9])$", var.maintenance_window))
+    error_message = "Maintenance window must be in the format 'ddd:hh24:mi-ddd:hh24:mi'. Eg: 'Mon:00:00-Mon:03:00'"
+  }
 }
 # Continuous backup takes place between 8 PM and 5 AM UTC.
 # Snapshot backups take place between 3 AM and 7 AM UTC.
@@ -283,18 +287,6 @@ variable "blue_green_update" {
   default     = {}
 }
 
-variable "backup_retention_period" { # TODO: Delete
-  description = "The days to retain backups for"
-  type        = number
-  default     = null
-}
-
-variable "backup_window" { # TODO: Delete
-  description = "The daily time range (in UTC) during which automated backups are created if they are enabled. Example: '09:46-10:16'. Must not overlap with maintenance_window"
-  type        = string
-  default     = null
-}
-
 variable "restore_to_point_in_time" {
   description = "Restore to a point in time (MySQL is NOT supported)"
   type        = map(string)