feat: allow task definitions to be used by Fargate (#37)

* set cpu and memory at task level, for fargate compatibility

* set fargate-incompatible variables to null by default

* style: run terraform fmt

* fix: use default values for cpu and memory

* test: update fixture data

Co-authored-by: Benjamin Chodoroff <bc@thermitic.net>

Author: jasonwalsh

main.tf

@@ -135,6 +135,11 @@ resource "aws_ecs_task_definition" "ecs_task_definition" {
   ipc_mode              = var.ipc_mode
   network_mode          = var.network_mode
   pid_mode              = var.pid_mode
+
+  # Fargate requires cpu and memory to be defined at the task level
+  cpu    = var.cpu
+  memory = var.memory
+
   dynamic "placement_constraints" {
     for_each = var.placement_constraints
     content {

test/fixtures/multiple.json

@@ -1,7 +1,7 @@
 [
   {
     "command": null,
-    "cpu": null,
+    "cpu": 256,
     "disableNetworking": false,
     "dnsSearchDomains": null,
     "dnsServers": null,
@@ -42,7 +42,7 @@
   },
   {
     "command": null,
-    "cpu": null,
+    "cpu": 256,
     "disableNetworking": false,
     "dnsSearchDomains": null,
     "dnsServers": null,

test/fixtures/single.json

@@ -1,7 +1,7 @@
 [
   {
     "command": null,
-    "cpu": null,
+    "cpu": 256,
     "disableNetworking": false,
     "dnsSearchDomains": null,
     "dnsServers": null,
@@ -68,7 +68,7 @@
         "awslogs-region": "us-east-1"
       }
     },
-    "memory": null,
+    "memory": 512,
     "memoryReservation": 512,
     "mountPoints": [
       {

variables.tf

@@ -8,8 +8,9 @@ variable "command" {
 }
 
 variable "cpu" {
-  default     = 0
+  default     = 256
   description = "The number of cpu units reserved for the container"
+  type        = number
 }
 
 variable "disableNetworking" {
@@ -95,7 +96,7 @@ variable "interactive" {
 }
 
 variable "ipc_mode" {
-  default     = "host"
+  default     = null
   description = "The IPC resource namespace to use for the containers in the task"
 }
 
@@ -118,8 +119,9 @@ variable "logConfiguration" {
 }
 
 variable "memory" {
-  default     = 0
+  default     = 512
   description = "The hard limit (in MiB) of memory to present to the container"
+  type        = number
 }
 
 variable "memoryReservation" {
@@ -144,7 +146,7 @@ variable "network_mode" {
 }
 
 variable "pid_mode" {
-  default     = "host"
+  default     = null
   description = "The process namespace to use for the containers in the task"
 }