Add slow_start parameter to ecs-service-with-alb (#151)

Author: jshoe

aws-ecs-service/README.md

@@ -166,6 +166,7 @@ service = false` argument can be removed.
 | registry\_secretsmanager\_arn | ARN for AWS Secrets Manager secret for credentials to private registry | string | `null` | no |
 | route53\_zone\_id | Zone in which to create an alias record to the ALB. | string | n/a | yes |
 | service | Service for tagging and naming. See [doc](../README.md#consistent-tagging). | string | n/a | yes |
+| slow_start | Seconds for targets to warm up before the load balancer sends them a full share of requests. | number | 60 | no |
 | ssl\_policy | ELB policy to determine which SSL/TLS encryption protocols are enabled. Probably don't touch this. | string | `null` | no |
 | subdomain | Subdomain in the zone. Final domain name will be subdomain.zone | string | n/a | yes |
 | tag\_service | Apply cost tags to the ECS service. Only specify false for backwards compatibility with old ECS services. | bool | `true` | no |

aws-ecs-service/alb.tf

@@ -15,6 +15,7 @@ resource "aws_lb_target_group" "service" {
   target_type = var.awsvpc_network_mode ? "ip" : "instance"
 
   deregistration_delay = 60
+  slow_start           = var.slow_start
 
   health_check {
     path     = var.health_check_path

aws-ecs-service/variables.tf

@@ -196,3 +196,9 @@ variable "ordered_placement_strategy" {
   default     = []
   description = "Placement strategy for the task instances."
 }
+
+variable "slow_start" {
+  description = "Seconds for targets to warm up before the load balancer sends them a full share of requests. 30-900 seconds or 0 to disable."
+  type        = number
+  default     = 60
+}