feat: Adding flag for enabling data cache in MSSQL module (#642)

Co-authored-by: Imran Nayer <imrannayer@google.com>

modules/mssql/README.md

@@ -40,6 +40,7 @@ module "mssql" {
 | backup\_configuration | The database backup configuration. | <pre>object({<br>    binary_log_enabled             = bool<br>    enabled                        = bool<br>    point_in_time_recovery_enabled = bool<br>    start_time                     = string<br>    transaction_log_retention_days = string<br>    retained_backups               = number<br>    retention_unit                 = string<br>  })</pre> | <pre>{<br>  "binary_log_enabled": null,<br>  "enabled": false,<br>  "point_in_time_recovery_enabled": null,<br>  "retained_backups": null,<br>  "retention_unit": null,<br>  "start_time": null,<br>  "transaction_log_retention_days": null<br>}</pre> | no |
 | connector\_enforcement | Enforce that clients use the connector library | `bool` | `false` | no |
 | create\_timeout | The optional timeout that is applied to limit long database creates. | `string` | `"30m"` | no |
+| data\_cache\_enabled | Whether data cache is enabled for the instance. Defaults to false. Feature is only available for ENTERPRISE\_PLUS tier and supported database\_versions | `bool` | `false` | no |
 | database\_flags | The database flags for the Cloud SQL. See [more details](https://cloud.google.com/sql/docs/sqlserver/flags) | <pre>list(object({<br>    name  = string<br>    value = string<br>  }))</pre> | `[]` | no |
 | database\_version | The database version to use: SQLSERVER\_2017\_STANDARD, SQLSERVER\_2017\_ENTERPRISE, SQLSERVER\_2017\_EXPRESS, or SQLSERVER\_2017\_WEB | `string` | `"SQLSERVER_2017_STANDARD"` | no |
 | db\_charset | The charset for the default database | `string` | `""` | no |

modules/mssql/main.tf

@@ -80,6 +80,12 @@ resource "google_sql_database_instance" "default" {
         }
       }
     }
+    dynamic "data_cache_config" {
+      for_each = var.edition == "ENTERPRISE_PLUS" && var.data_cache_enabled ? ["cache_enabled"] : []
+      content {
+        data_cache_enabled = var.data_cache_enabled
+      }
+    }
     dynamic "deny_maintenance_period" {
       for_each = local.is_secondary_instance ? [] : var.deny_maintenance_period
       content {

modules/mssql/variables.tf

@@ -171,6 +171,12 @@ variable "database_flags" {
   default = []
 }
 
+variable "data_cache_enabled" {
+  description = "Whether data cache is enabled for the instance. Defaults to false. Feature is only available for ENTERPRISE_PLUS tier and supported database_versions"
+  type        = bool
+  default     = false
+}
+
 variable "active_directory_config" {
   description = "Active domain that the SQL instance will join."
   type        = map(string)