Allow increasing ephemeral storage on Fargate services.

Author: tobyclemson

spec/unit/infra/root/main.tf

@@ -70,6 +70,7 @@ module "ecs_service" {
   use_fargate = var.use_fargate
   service_task_cpu = var.service_task_cpu
   service_task_memory = var.service_task_memory
+  service_task_ephemeral_storage = var.service_task_ephemeral_storage
   service_task_operating_system_family = var.service_task_operating_system_family
   service_task_cpu_architecture = var.service_task_cpu_architecture
 

spec/unit/infra/root/variables.tf

@@ -158,6 +158,11 @@ variable "service_task_memory" {
   default = null
 }
 
+variable "service_task_ephemeral_storage" {
+  type    = number
+  default = null
+}
+
 variable "service_task_operating_system_family" {
   type    = string
   default = null

spec/unit/task_definition_spec.rb

@@ -224,6 +224,7 @@
           vars.use_fargate = true
           vars.service_task_cpu = '1234'
           vars.service_task_memory = '4567'
+          vars.service_task_ephemeral_storage = 100
           vars.service_task_operating_system_family = 'WINDOWS_SERVER_2019_FULL'
           vars.service_task_cpu_architecture = 'ARM64'
         end
@@ -247,14 +248,23 @@
                 .with_attribute_value(:memory, '4567'))
       end
 
+      it 'uses the provided memory value' do
+        expect(@plan)
+          .to(include_resource_creation(type: 'aws_ecs_task_definition')
+                .with_attribute_value(
+                  :ephemeral_storage, [{
+                    size_in_gib: 100
+                  }]
+                ))
+      end
+
       it 'uses the provided cpu and OS values' do
         expect(@plan)
           .to(include_resource_creation(type: 'aws_ecs_task_definition')
                 .with_attribute_value(
                   :runtime_platform, [{
                     cpu_architecture: 'ARM64',
                     operating_system_family: 'WINDOWS_SERVER_2019_FULL'
-
                   }]
                 ))
       end

task_definition.tf

@@ -85,6 +85,13 @@ resource "aws_ecs_task_definition" "service" {
     cpu_architecture        = var.use_fargate ? var.service_task_cpu_architecture : null
   }
 
+  dynamic "ephemeral_storage" {
+    for_each = var.use_fargate && var.service_task_ephemeral_storage != null ? [var.service_task_ephemeral_storage] : []
+    content {
+      size_in_gib = ephemeral_storage.value
+    }
+  }
+
   dynamic "volume" {
     for_each = var.service_volumes
     content {

variables.tf

@@ -277,6 +277,12 @@ variable "service_task_memory" {
   nullable    = false
 }
 
+variable "service_task_ephemeral_storage" {
+  description = "The total amount of ephemeral storage (in GiB) to set for the service task when deployed using Fargate."
+  type        = number
+  default     = null
+}
+
 variable "service_task_operating_system_family" {
   description = "The operating system family to use for the service task when deployed using Fargate."
   type        = string