Adding the option to defina an empty ALB SGs (#40)

* Adding the option to defina an empty ALB SGs

* fixning security group rules

* Adding default for alb_sg and updating readme

* Adding var.use_alb_security_group

* Updatind readme for new var.use_alb_security_group

* removing != from conditional since if not needed

README.md

@@ -181,7 +181,7 @@ Available targets:
 
 | Name | Description | Type | Default | Required |
 |------|-------------|:----:|:-----:|:-----:|
-| alb_security_group | Security group of the ALB | string | - | yes |
+| alb_security_group | Security group of the ALB | string | `` | no |
 | assign_public_ip | Assign a public IP address to the ENI (Fargate launch type only). Valid values are `true` or `false`. Default `false` | bool | `false` | no |
 | attributes | Additional attributes (_e.g._ "1") | list(string) | `<list>` | no |
 | container_definition_json | The JSON of the task container definition | string | - | yes |
@@ -214,6 +214,7 @@ Available targets:
 | task_cpu | The number of CPU units used by the task. If using `FARGATE` launch type `task_cpu` must match supported memory values (https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task_definition_parameters.html#task_size) | number | `256` | no |
 | task_memory | The amount of memory (in MiB) used by the task. If using Fargate launch type `task_memory` must match supported cpu value (https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task_definition_parameters.html#task_size) | number | `512` | no |
 | task_placement_constraints | A set of placement constraints rules that are taken into consideration during task placement. Maximum number of placement_constraints is 10. See `placement_constraints` docs https://www.terraform.io/docs/providers/aws/r/ecs_task_definition.html#placement-constraints-arguments | object | `<list>` | no |
+| use_alb_security_group | A flag to enable/disable adding the ingress rule to the ALB security group | bool | `false` | no |
 | volumes | Task volume definitions as list of configuration objects | object | `<list>` | no |
 | vpc_id | The VPC ID where resources are created | string | - | yes |
 

docs/terraform.md

@@ -2,7 +2,7 @@
 
 | Name | Description | Type | Default | Required |
 |------|-------------|:----:|:-----:|:-----:|
-| alb_security_group | Security group of the ALB | string | - | yes |
+| alb_security_group | Security group of the ALB | string | `` | no |
 | assign_public_ip | Assign a public IP address to the ENI (Fargate launch type only). Valid values are `true` or `false`. Default `false` | bool | `false` | no |
 | attributes | Additional attributes (_e.g._ "1") | list(string) | `<list>` | no |
 | container_definition_json | The JSON of the task container definition | string | - | yes |
@@ -35,6 +35,7 @@
 | task_cpu | The number of CPU units used by the task. If using `FARGATE` launch type `task_cpu` must match supported memory values (https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task_definition_parameters.html#task_size) | number | `256` | no |
 | task_memory | The amount of memory (in MiB) used by the task. If using Fargate launch type `task_memory` must match supported cpu value (https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task_definition_parameters.html#task_size) | number | `512` | no |
 | task_placement_constraints | A set of placement constraints rules that are taken into consideration during task placement. Maximum number of placement_constraints is 10. See `placement_constraints` docs https://www.terraform.io/docs/providers/aws/r/ecs_task_definition.html#placement-constraints-arguments | object | `<list>` | no |
+| use_alb_security_group | A flag to enable/disable adding the ingress rule to the ALB security group | bool | `false` | no |
 | volumes | Task volume definitions as list of configuration objects | object | `<list>` | no |
 | vpc_id | The VPC ID where resources are created | string | - | yes |
 

main.tf

@@ -223,7 +223,7 @@ resource "aws_security_group_rule" "allow_icmp_ingress" {
 }
 
 resource "aws_security_group_rule" "alb" {
-  count                    = var.enabled ? 1 : 0
+  count                    = var.enabled && var.use_alb_security_group ? 1 : 0
   type                     = "ingress"
   from_port                = 0
   to_port                  = var.container_port

variables.tf

@@ -47,6 +47,7 @@ variable "vpc_id" {
 variable "alb_security_group" {
   type        = string
   description = "Security group of the ALB"
+  default     = ""
 }
 
 variable "ecs_cluster_arn" {
@@ -234,3 +235,9 @@ variable "service_registries" {
   description = "The service discovery registries for the service. The maximum number of service_registries blocks is 1. The currently supported service registry is Amazon Route 53 Auto Naming Service - `aws_service_discovery_service`; see `service_registries` docs https://www.terraform.io/docs/providers/aws/r/ecs_service.html#service_registries-1"
   default     = []
 }
+
+variable "use_alb_security_group" {
+  type        = bool
+  description = "A flag to enable/disable adding the ingress rule to the ALB security group"
+  default     = false
+}