fix: made 'allocated_ip_range' variable optional (#395)

modules/safer_mysql/README.md

@@ -167,7 +167,7 @@ mysql -S $HOME/mysql_sockets/myproject:region:instance -u user -p
 | activation\_policy | The activation policy for the master instance. Can be either `ALWAYS`, `NEVER` or `ON_DEMAND`. | `string` | `"ALWAYS"` | no |
 | additional\_databases | A list of databases to be created in your cluster | <pre>list(object({<br>    name      = string<br>    charset   = string<br>    collation = string<br>  }))</pre> | `[]` | no |
 | additional\_users | A list of users to be created in your cluster | <pre>list(object({<br>    name     = string<br>    password = string<br>    host     = string<br>    type     = string<br>  }))</pre> | `[]` | no |
-| allocated\_ip\_range | Existing allocated IP range name for the Private IP CloudSQL instance. The networks needs to be configured with https://cloud.google.com/vpc/docs/configure-private-services-access. | `string` | n/a | yes |
+| allocated\_ip\_range | Existing allocated IP range name for the Private IP CloudSQL instance. The networks needs to be configured with https://cloud.google.com/vpc/docs/configure-private-services-access. | `string` | `null` | no |
 | assign\_public\_ip | Set to true if the master instance should also have a public IP (less secure). | `string` | `false` | no |
 | availability\_type | The availability type for the master instance. Can be either `REGIONAL` or `null`. | `string` | `"REGIONAL"` | no |
 | backup\_configuration | The backup\_configuration settings subblock for the database setings | <pre>object({<br>    binary_log_enabled             = bool<br>    enabled                        = bool<br>    start_time                     = string<br>    location                       = string<br>    transaction_log_retention_days = string<br>    retained_backups               = number<br>    retention_unit                 = string<br>  })</pre> | <pre>{<br>  "binary_log_enabled": false,<br>  "enabled": false,<br>  "location": null,<br>  "retained_backups": null,<br>  "retention_unit": null,<br>  "start_time": null,<br>  "transaction_log_retention_days": null<br>}</pre> | no |

modules/safer_mysql/variables.tf

@@ -48,10 +48,10 @@ variable "vpc_network" {
   type        = string
 }
 
-// required
 variable "allocated_ip_range" {
   description = "Existing allocated IP range name for the Private IP CloudSQL instance. The networks needs to be configured with https://cloud.google.com/vpc/docs/configure-private-services-access."
   type        = string
+  default     = null
 }
 
 // Master