chore(snapshot): Allow restore from a snapshot (#46)

README.md

@@ -143,6 +143,7 @@ No modules.
 | <a name="input_preferred_cache_cluster_azs"></a> [preferred\_cache\_cluster\_azs](#input\_preferred\_cache\_cluster\_azs) | A list of EC2 availability zones in which the replication group's cache clusters will be created. The order of the availability zones in the list is not important. | `list(string)` | `null` | no |
 | <a name="input_replicas_per_node_group"></a> [replicas\_per\_node\_group](#input\_replicas\_per\_node\_group) | Specify the number of replica nodes in each node group. Valid values are 0 to 5. Changing this number will trigger an online resizing operation before other settings modifications. | `number` | `0` | no |
 | <a name="input_security_group_ids"></a> [security\_group\_ids](#input\_security\_group\_ids) | List of Security Groups. | `list(string)` | `[]` | no |
+| <a name="input_snapshot_name"></a> [snapshot\_name](#input\_snapshot\_name) | The name of a snapshot from which to restore data into the new node group. Changing the snapshot\_name forces a new resource. | `string` | `null` | no |
 | <a name="input_snapshot_retention_limit"></a> [snapshot\_retention\_limit](#input\_snapshot\_retention\_limit) | The number of days for which ElastiCache will retain automatic cache cluster snapshots before deleting them. | `number` | `30` | no |
 | <a name="input_snapshot_window"></a> [snapshot\_window](#input\_snapshot\_window) | The daily time range (in UTC) during which ElastiCache will begin taking a daily snapshot of your cache cluster. | `string` | `""` | no |
 | <a name="input_subnet_group_name"></a> [subnet\_group\_name](#input\_subnet\_group\_name) | The name of the subnet group. If it is not specified, the module will create one for you | `string` | `null` | no |

main.tf

@@ -20,6 +20,7 @@ resource "aws_elasticache_replication_group" "redis" {
   maintenance_window         = var.maintenance_window
   snapshot_window            = var.snapshot_window
   snapshot_retention_limit   = var.snapshot_retention_limit
+  snapshot_name              = var.snapshot_name
   final_snapshot_identifier  = var.final_snapshot_identifier
   automatic_failover_enabled = var.automatic_failover_enabled && var.num_cache_clusters >= 2 ? true : false
   auto_minor_version_upgrade = var.auto_minor_version_upgrade

variables.tf

@@ -79,6 +79,12 @@ variable "maintenance_window" {
   description = "Specifies the weekly time range for when maintenance on the cache cluster is performed."
 }
 
+variable "snapshot_name" {
+  type        = string
+  description = "The name of a snapshot from which to restore data into the new node group. Changing the snapshot_name forces a new resource."
+  default     = null
+}
+
 variable "snapshot_window" {
   default     = ""
   type        = string