Fix for creating when cluster does not exist yet

README.md

@@ -66,6 +66,7 @@ In addition you have the option to create or not :
 | alarm\_min\_healthy\_tasks | Alarm when the number of healthy tasks is less than this number (use 0 to disable this alarm) | `number` | `2` | no |
 | alarm\_prefix | String prefix for cloudwatch alarms. (Optional) | `string` | `"alarm"` | no |
 | alarm\_sns\_topics | Alarm topics to create and alert on ECS service metrics. Leaving empty disables all alarms. | `list` | `[]` | no |
+| alb\_arn | ALB ARN created by ECS cluster module | `any` | n/a | yes |
 | alb\_dns\_name | ALB DNS Name | `string` | `""` | no |
 | alb\_listener\_https\_arn | ALB HTTPS Listener created by ECS cluster module | `any` | n/a | yes |
 | alb\_name | ALB name - Required if it is an internal one | `string` | `""` | no |
@@ -93,6 +94,7 @@ In addition you have the option to create or not :
 | cloudwatch\_logs\_create | Whether to create cloudwatch log resources or not | `bool` | `true` | no |
 | cloudwatch\_logs\_export | Whether to mark the log group to export to an S3 bucket (needs terraform-aws-log-exporter to be deployed in the account/region) | `bool` | `false` | no |
 | cloudwatch\_logs\_retention | Specifies the number of days you want to retain log events in the specified log group. Possible values are: 1, 3, 5, 7, 14, 30, 60, 90, 120, 150, 180, 365, 400, 545, 731, 1827, and 3653. | `number` | `120` | no |
+| cluster\_arn | n/a | `string` | `"ARN of existing ECS Cluster to deploy this app to"` | no |
 | cluster\_name | n/a | `string` | `"Name of existing ECS Cluster to deploy this app to"` | no |
 | command | Command to run on container | `list(string)` | `null` | no |
 | compat\_keep\_target\_group\_naming | Keeps old naming convention for target groups to avoid recreation of resource in production environments | `bool` | `false` | no |

_data.tf

@@ -1,13 +1,5 @@
 data "aws_region" "current" {}
 
-data "aws_lb_listener" "ecs" {
-  arn = var.alb_listener_https_arn
-}
-
 data "aws_iam_account_alias" "current" {
   count = var.alarm_prefix == "" ? 1 : 0
 }
-
-data "aws_ecs_cluster" "ecs_cluster" {
-  cluster_name = var.cluster_name
-}

_variables.tf

@@ -87,6 +87,10 @@ variable "cluster_name" {
   default = "Name of existing ECS Cluster to deploy this app to"
 }
 
+variable "cluster_arn" {
+  default = "ARN of existing ECS Cluster to deploy this app to"
+}
+
 variable "service_role_arn" {
   description = "Existing service role ARN created by ECS cluster module"
   default     = null
@@ -135,6 +139,10 @@ variable "alb_listener_https_arn" {
   description = "ALB HTTPS Listener created by ECS cluster module"
 }
 
+variable "alb_arn" {
+  description = "ALB ARN created by ECS cluster module"
+}
+
 variable "alb_dns_name" {
   description = "ALB DNS Name"
   default     = ""

cloudwatch-alarms.tf

@@ -18,7 +18,7 @@ resource "aws_cloudwatch_metric_alarm" "min_healthy_tasks" {
   unit        = "Count"
 
   dimensions = {
-    LoadBalancer = join("/", slice(split("/", data.aws_lb_listener.ecs.load_balancer_arn), 1, 4))
+    LoadBalancer = join("/", slice(split("/", var.alb_arn), 1, 4))
     TargetGroup  = aws_lb_target_group.green.arn_suffix
   }
 

cloudwatch-ecs-event-logs.tf

@@ -17,7 +17,7 @@ resource "aws_cloudwatch_event_rule" "ecs_events" {
   "source": ["aws.ecs"],
   "detail-type": ["ECS Task State Change", "ECS Container Instance State Change"],
   "detail": {
-    "clusterArn": ["${data.aws_ecs_cluster.ecs_cluster.arn}"],
+    "clusterArn": ["${var.cluster_arn}"],
     "group": ["service:${var.name}"]
   }
 }
@@ -59,4 +59,4 @@ resource "aws_cloudwatch_log_resource_policy" "ecs_events" {
   policy_document = data.aws_iam_policy_document.ecs_events[0].json
   policy_name     = "capture-ecs-events-${var.cluster_name}-${var.name}"
 
-}
+}