make the load balancer optional

Author: briskt

main.tf

@@ -66,10 +66,14 @@ resource "aws_ecs_service" "service" {
     }
   }
 
-  load_balancer {
-    target_group_arn = var.tg_arn
-    container_name   = var.lb_container_name
-    container_port   = var.lb_container_port
+  dynamic "load_balancer" {
+    for_each = var.load_balancer
+
+    content {
+      container_name   = load_balancer.value.container_name
+      container_port   = load_balancer.value.container_port
+      target_group_arn = load_balancer.value.target_group_arn
+    }
   }
 
   # Track the latest ACTIVE revision

test/main.tf

@@ -7,9 +7,6 @@ module "minimal" {
   service_env        = ""
   container_def_json = ""
   desired_count      = "1"
-  lb_container_name  = ""
-  lb_container_port  = "80"
-  tg_arn             = ""
   ecsServiceRole_arn = ""
 }
 
@@ -21,17 +18,20 @@ module "full" {
   service_env        = ""
   container_def_json = ""
   desired_count      = "1"
-  lb_container_name  = ""
-  lb_container_port  = "80"
-  tg_arn             = ""
+
+  load_balancer = [{
+    target_group_arn = ""
+    container_name   = ""
+    container_port   = 80
+  }]
   ecsServiceRole_arn = ""
 
   availability_zone_rebalancing      = "ENABLED"
   volumes                            = []
   task_role_arn                      = ""
   network_mode                       = "bridge"
-  deployment_maximum_percent         = "200"
-  deployment_minimum_healthy_percent = "50"
+  deployment_maximum_percent         = 200
+  deployment_minimum_healthy_percent = 50
   ordered_placement_strategy = [
     {
       type  = "spread"

variables.tf

@@ -2,50 +2,73 @@
  * Required Variables
  */
 
-variable "cluster_id" {
-  type = string
-}
-
 variable "service_name" {
-  type = string
-}
-
-variable "service_env" {
-  type = string
+  description = "Name of the service, up to 255 letters (uppercase and lowercase), numbers, underscores, and hyphens."
+  type        = string
 }
 
 variable "container_def_json" {
-  type = string
+  description = "A list of valid container definitions provided as a single valid JSON document."
+  type        = string
 }
 
 variable "desired_count" {
-  type = string
+  description = "The number of instances of the task definition to place and keep running."
+  type        = number
 }
 
-variable "lb_container_name" {
-  type = string
-}
 
-variable "lb_container_port" {
-  type = string
+/*
+ * Optional Variables
+ */
+
+variable "cluster_id" {
+  description = "ARN of the ECS cluster in which to place this service. If not specified, the default cluster is used."
+  type        = string
+  default     = null
 }
 
-variable "tg_arn" {
-  type = string
+variable "service_env" {
+  description = "Name of environment, used in naming task definition. Example: \"prod\"."
+  type        = string
+  default     = "prod"
+}
+
+variable "load_balancer" {
+  description = <<-EOF
+    Configuration block for load balancers.
+    Attributes:
+      target_group_arn - ARN of the Load Balancer target group to associate with the service.
+      container_name   - Container name to associate with the load balancer (as it appears in container definition).
+      container_port   - Port on the container to associate with the load balancer.
+    Example:
+      [{
+        target_group_arn = aws_alb_target_group.this.arn
+        container_name   = "app"
+        container_port   = 80
+      }]
+    EOF
+  type = list(object({
+    target_group_arn = string
+    container_name   = string
+    container_port   = number
+  }))
+  default = []
 }
 
 variable "ecsServiceRole_arn" {
-  type = string
+  description = <<-EOF
+    ARN of the IAM role that allows Amazon ECS to make calls to your load balancer on your behalf. Required if using a
+    load balancer.
+    EOF
+  type        = string
+  default     = null
 }
 
-/*
- * Optional Variables
- */
-
 variable "availability_zone_rebalancing" {
-  description = <<EOF
-    "When enabled, ECS automatically redistributes tasks within a service across Availability Zones. Must be
-    "either \"ENABLED\" or \"DISABLED\"."
+  description = <<-EOF
+    When enabled, ECS automatically redistributes tasks within a service across Availability Zones. Must be
+    either "ENABLED" or "DISABLED".
   EOF
   type        = string
   default     = "DISABLED"
@@ -58,36 +81,55 @@ variable "volumes" {
 }
 
 variable "task_role_arn" {
-  type    = string
-  default = ""
+  description = "ARN of IAM role that allows your Amazon ECS container task to make calls to other AWS services."
+  type        = string
+  default     = null
 }
 
 variable "network_mode" {
-  type    = string
-  default = "bridge"
+  description = <<-EOF
+    Docker networking mode to use for the containers in the task. Valid values are "none", "bridge", "awsvpc",
+    and "host".
+    EOF
+  type        = string
+  default     = "bridge"
 }
 
 variable "deployment_maximum_percent" {
-  type    = string
-  default = 200
+  description = <<-EOF
+    Upper limit (as a percentage of the service's desiredCount) of the number of running tasks that can be running in a
+    service during a deployment.
+    EOF
+  type        = number
+  default     = 200
 }
 
 variable "deployment_minimum_healthy_percent" {
-  type    = string
-  default = 50
+  description = <<-EOF
+    Lower limit (as a percentage of the service's desiredCount) of the number of running tasks that must remain running
+    and healthy in a service during a deployment.
+    EOF
+  type        = number
+  default     = 50
 }
 
 variable "ordered_placement_strategy" {
-  description = ""
-  type        = list(any)
+  description = "Service level strategy rules that are taken into consideration during task placement."
+  type = list(object({
+    type  = string
+    field = string
+  }))
   default = [{
     type  = "spread"
     field = "instanceId"
   }]
 }
 
 variable "execution_role_arn" {
-  description = "The IAM role that allows ECS to make AWS API calls on your behalf, such as to pull container images from ECR when using Fargate or to reference secrets from SSM Parameter Store."
+  description = <<-EOF
+    The IAM role that allows ECS to make AWS API calls on your behalf, such as to pull container images from ECR when
+    using Fargate or to reference secrets from SSM Parameter Store.
+    EOF
   type        = string
-  default     = ""
+  default     = null
 }