Adds distinct task vs app - memory and CPU

infra/modules/service/main.tf

@@ -90,8 +90,8 @@ resource "aws_ecs_task_definition" "app" {
     {
       name                   = local.container_name,
       image                  = local.image_url,
-      memory                 = var.memory,
-      cpu                    = var.cpu,
+      memory                 = var.app_memory,
+      cpu                    = var.app_cpu,
       networkMode            = "awsvpc",
       essential              = true,
       readonlyRootFilesystem = !var.enable_command_execution,
@@ -147,8 +147,8 @@ resource "aws_ecs_task_definition" "app" {
     }
   }
 
-  cpu    = var.cpu
-  memory = var.memory
+  cpu    = var.task_cpu
+  memory = var.task_memory
 
   requires_compatibilities = ["FARGATE"]
 

infra/modules/service/variables.tf

@@ -10,10 +10,16 @@ variable "container_port" {
   default     = 8000
 }
 
-variable "cpu" {
+variable "app_cpu" {
   type        = number
   default     = 256
-  description = "Number of cpu units used by the task, expessed as an integer value, e.g 512 "
+  description = "Number of cpu units used by the primary application container, expessed as an integer value, e.g 512 "
+}
+
+variable "task_cpu" {
+  type        = number
+  default     = 256
+  description = "Number of cpu units used by the task definition, expessed as an integer value, e.g 512. Identical to app_cpu if you are not running any sidecar containers."
 }
 
 variable "db_vars" {
@@ -124,10 +130,16 @@ variable "is_temporary" {
   default     = false
 }
 
-variable "memory" {
+variable "app_memory" {
+  type        = number
+  default     = 512
+  description = "Amount (in MiB) of memory used by the primary application container. e.g. 2048"
+}
+
+variable "task_memory" {
   type        = number
   default     = 512
-  description = "Amount (in MiB) of memory used by the task. e.g. 2048"
+  description = "Amount (in MiB) of memory used by the task definition. e.g. 2048. Identical to app_cpu if you are not running any sidecar containers."
 }
 
 variable "network_name" {

infra/{{app_name}}/app-config/env-config/service.tf

@@ -2,8 +2,10 @@ locals {
   service_config = {
     service_name             = "${var.app_name}-${var.environment}"
     region                   = var.default_region
-    cpu                      = var.service_cpu
-    memory                   = var.service_memory
+    app_cpu                  = var.app_cpu
+    task_cpu                 = var.task_cpu
+    app_memory               = var.app_memory
+    task_memory              = var.task_memory
     desired_instance_count   = var.service_desired_instance_count
     enable_command_execution = var.enable_command_execution
 

infra/{{app_name}}/app-config/env-config/variables.tf

@@ -87,7 +87,12 @@ variable "project_name" {
   type = string
 }
 
-variable "service_cpu" {
+variable "app_cpu" {
+  type    = number
+  default = 256
+}
+
+variable "task_cpu" {
   type    = number
   default = 256
 }
@@ -97,7 +102,12 @@ variable "service_desired_instance_count" {
   default = 1
 }
 
-variable "service_memory" {
+variable "app_memory" {
+  type    = number
+  default = 512
+}
+
+variable "task_memory" {
   type    = number
   default = 512
 }

infra/{{app_name}}/app-config/prod.tf

@@ -15,8 +15,13 @@ module "prod_config" {
   # These numbers are a starting point based on this article
   # Update the desired instance size and counts based on the project's specific needs
   # https://conchchow.medium.com/aws-ecs-fargate-compute-capacity-planning-a5025cb40bd0
-  service_cpu                    = 1024
-  service_memory                 = 4096
+  #
+  # See the following link for a description of the cpu and memory constraints.
+  # https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task_definition_parameters.html#task_size
+  app_cpu                        = 1024
+  task_cpu                       = 1024
+  app_memory                     = 4096
+  task_memory                    = 4096
   service_desired_instance_count = 3
 
   # Enables ECS Exec access for debugging or jump access.

infra/{{app_name}}/service/main.tf

@@ -72,8 +72,10 @@ module "service" {
 
   enable_waf = module.app_config.enable_waf
 
-  cpu                      = local.service_config.cpu
-  memory                   = local.service_config.memory
+  app_cpu                  = local.service_config.app_cpu
+  task_cpu                 = local.service_config.task_cpu
+  app_memory               = local.service_config.app_memory
+  task_memory              = local.service_config.task_memory
   desired_instance_count   = local.service_config.desired_instance_count
   enable_command_execution = local.service_config.enable_command_execution