ECS Cluster time based autoscaling

* Allows configuring time based autoscaling for the Infrastructure ECS
  Cluster's autoscaling group.
* Cron expressions can be provided to set the desired capacity to the
  min or max sizes. Custom scaling sizes can also be provided, to set
  the min/max sizes for a given cron expression (in which case the min
  size will be set as the desired capacity)

README.md

@@ -29,6 +29,9 @@ This project creates and manages resources within an AWS account for infrastruct
 | [aws_athena_workgroup.infrastructure_vpc_flow_logs](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/athena_workgroup) | resource |
 | [aws_autoscaling_group.infrastructure_ecs_cluster](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/autoscaling_group) | resource |
 | [aws_autoscaling_lifecycle_hook.infrastructure_ecs_cluster_termination](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/autoscaling_lifecycle_hook) | resource |
+| [aws_autoscaling_schedule.ecs_infrastructure_time_based_custom](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/autoscaling_schedule) | resource |
+| [aws_autoscaling_schedule.ecs_infrastructure_time_based_max](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/autoscaling_schedule) | resource |
+| [aws_autoscaling_schedule.ecs_infrastructure_time_based_min](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/autoscaling_schedule) | resource |
 | [aws_cloudwatch_log_group.ecs_cluster_infrastructure_draining_lambda_log_group](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/cloudwatch_log_group) | resource |
 | [aws_cloudwatch_log_group.infrastructure_vpc_flow_logs](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/cloudwatch_log_group) | resource |
 | [aws_default_network_acl.infrastructure](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/default_network_acl) | resource |
@@ -121,6 +124,9 @@ This project creates and manages resources within an AWS account for infrastruct
 | <a name="input_infrastructure_dockerhub_email"></a> [infrastructure\_dockerhub\_email](#input\_infrastructure\_dockerhub\_email) | Dockerhub email | `string` | n/a | yes |
 | <a name="input_infrastructure_dockerhub_token"></a> [infrastructure\_dockerhub\_token](#input\_infrastructure\_dockerhub\_token) | Dockerhub token which has permissions to pull images | `string` | n/a | yes |
 | <a name="input_infrastructure_ecs_cluster_ami_version"></a> [infrastructure\_ecs\_cluster\_ami\_version](#input\_infrastructure\_ecs\_cluster\_ami\_version) | AMI version for ECS cluster instances (amzn2-ami-ecs-hvm-<version>) | `string` | n/a | yes |
+| <a name="input_infrastructure_ecs_cluster_autoscaling_time_based_custom"></a> [infrastructure\_ecs\_cluster\_autoscaling\_time\_based\_custom](#input\_infrastructure\_ecs\_cluster\_autoscaling\_time\_based\_custom) | List of objects with min/max sizes and cron expressions to scale the ECS cluster. Min size will be used as desired. | <pre>list(<br>    object({<br>      cron = string<br>      min  = number<br>      max  = number<br>    })<br>  )</pre> | n/a | yes |
+| <a name="input_infrastructure_ecs_cluster_autoscaling_time_based_max"></a> [infrastructure\_ecs\_cluster\_autoscaling\_time\_based\_max](#input\_infrastructure\_ecs\_cluster\_autoscaling\_time\_based\_max) | List of cron expressions to scale the ECS cluster to the configured max size | `list(string)` | n/a | yes |
+| <a name="input_infrastructure_ecs_cluster_autoscaling_time_based_min"></a> [infrastructure\_ecs\_cluster\_autoscaling\_time\_based\_min](#input\_infrastructure\_ecs\_cluster\_autoscaling\_time\_based\_min) | List of cron expressions to scale the ECS cluster to the configured min size | `list(string)` | n/a | yes |
 | <a name="input_infrastructure_ecs_cluster_draining_lambda_enabled"></a> [infrastructure\_ecs\_cluster\_draining\_lambda\_enabled](#input\_infrastructure\_ecs\_cluster\_draining\_lambda\_enabled) | Enable the Lambda which ensures all containers have drained before terminating ECS cluster instances | `bool` | n/a | yes |
 | <a name="input_infrastructure_ecs_cluster_draining_lambda_log_retention"></a> [infrastructure\_ecs\_cluster\_draining\_lambda\_log\_retention](#input\_infrastructure\_ecs\_cluster\_draining\_lambda\_log\_retention) | Log retention for the ECS cluster draining Lambda | `number` | n/a | yes |
 | <a name="input_infrastructure_ecs_cluster_ebs_docker_storage_volume_size"></a> [infrastructure\_ecs\_cluster\_ebs\_docker\_storage\_volume\_size](#input\_infrastructure\_ecs\_cluster\_ebs\_docker\_storage\_volume\_size) | Size of EBS volume for Docker storage on the infrastructure ECS instances | `number` | n/a | yes |

ecs-cluster-infrastructure-autoscaling-time-based.tf

@@ -0,0 +1,32 @@
+resource "aws_autoscaling_schedule" "ecs_infrastructure_time_based_max" {
+  for_each = local.enable_infrastructure_ecs_cluster ? local.infrastructure_ecs_cluster_autoscaling_time_based_max : []
+
+  autoscaling_group_name = aws_autoscaling_group.infrastructure_ecs_cluster[0].name
+  scheduled_action_name  = "${local.resource_prefix}-time-based-max ${each.value}"
+  desired_capacity       = local.infrastructure_ecs_cluster_max_size
+  min_size               = -1
+  max_size               = -1
+  recurrence             = each.value
+}
+
+resource "aws_autoscaling_schedule" "ecs_infrastructure_time_based_min" {
+  for_each = local.enable_infrastructure_ecs_cluster ? local.infrastructure_ecs_cluster_autoscaling_time_based_min : []
+
+  autoscaling_group_name = aws_autoscaling_group.infrastructure_ecs_cluster[0].name
+  scheduled_action_name  = "${local.resource_prefix}-time-based-min ${each.value}"
+  desired_capacity       = local.infrastructure_ecs_cluster_min_size
+  min_size               = -1
+  max_size               = -1
+  recurrence             = each.value
+}
+
+resource "aws_autoscaling_schedule" "ecs_infrastructure_time_based_custom" {
+  for_each = local.enable_infrastructure_ecs_cluster ? local.infrastructure_ecs_cluster_autoscaling_time_based_custom : {}
+
+  autoscaling_group_name = aws_autoscaling_group.infrastructure_ecs_cluster[0].name
+  scheduled_action_name  = "${local.resource_prefix}-time-based-custom ${each.value["cron"]}  ${each.value["min"]}-${each.value["max"]}"
+  desired_capacity       = each.value["min"]
+  min_size               = each.value["min"]
+  max_size               = each.value["max"]
+  recurrence             = each.value["cron"]
+}

locals.tf

@@ -107,6 +107,11 @@ locals {
   infrastructure_ecs_cluster_min_size                              = var.infrastructure_ecs_cluster_min_size
   infrastructure_ecs_cluster_max_size                              = var.infrastructure_ecs_cluster_max_size
   infrastructure_ecs_cluster_max_instance_lifetime                 = var.infrastructure_ecs_cluster_max_instance_lifetime
+  infrastructure_ecs_cluster_autoscaling_time_based_max            = toset(var.infrastructure_ecs_cluster_autoscaling_time_based_max)
+  infrastructure_ecs_cluster_autoscaling_time_based_min            = toset(var.infrastructure_ecs_cluster_autoscaling_time_based_min)
+  infrastructure_ecs_cluster_autoscaling_time_based_custom = {
+    for custom in toset(var.infrastructure_ecs_cluster_autoscaling_time_based_custom) : "${custom["min"]}-${custom["max"]} ${custom["cron"]}" => custom
+  }
   infrastructure_ecs_cluster_user_data = base64encode(
     templatefile("ec2-userdata/ecs-instance.tpl", {
       docker_storage_volume_device_name = local.infrastructure_ecs_cluster_ebs_docker_storage_volume_device_name,

variables.tf

@@ -264,3 +264,24 @@ variable "infrastructure_ecs_cluster_max_instance_lifetime" {
   description = "Maximum lifetime in seconds of an instance within the ECS cluster"
   type        = number
 }
+
+variable "infrastructure_ecs_cluster_autoscaling_time_based_max" {
+  description = "List of cron expressions to scale the ECS cluster to the configured max size"
+  type        = list(string)
+}
+
+variable "infrastructure_ecs_cluster_autoscaling_time_based_min" {
+  description = "List of cron expressions to scale the ECS cluster to the configured min size"
+  type        = list(string)
+}
+
+variable "infrastructure_ecs_cluster_autoscaling_time_based_custom" {
+  description = "List of objects with min/max sizes and cron expressions to scale the ECS cluster. Min size will be used as desired."
+  type = list(
+    object({
+      cron = string
+      min  = number
+      max  = number
+    })
+  )
+}