Merge pull request #1 from gaussb-labs/feature/add-healthcheck-support-in-alb

feat: add healthcheck block to target group configuration

Author: premdeepsaini

main.tf

@@ -1,9 +1,9 @@
 locals {
-  managed_by                     = "Terraform"
-  target_group_app_name          = "app"
-  alb_listener_app_http_name     = "app_http"
-  alb_listener_app_https_name    = "app_https"
-  alb_listener_rule_app_name = "app"
+  managed_by                  = "Terraform"
+  target_group_app_name       = "app"
+  alb_listener_app_http_name  = "app_http"
+  alb_listener_app_https_name = "app_https"
+  alb_listener_rule_app_name  = "app"
 }
 
 resource "aws_lb" "alb" {
@@ -30,6 +30,17 @@ resource "aws_lb_target_group" "app" {
   port     = var.app_port
   protocol = "HTTP"
   vpc_id   = var.vpc_id
+  health_check {
+    enabled             = var.target_group_app_enabled
+    healthy_threshold   = var.target_group_app_healthy_threshold
+    unhealthy_threshold = var.target_group_app_unhealthy_threshold
+    interval            = var.target_group_app_interval
+    matcher             = var.target_group_app_matcher
+    path                = var.target_group_app_path
+    port                = var.target_group_app_port
+    protocol            = var.target_group_app_protocol
+    timeout             = var.target_group_app_timeout
+  }
   tags = {
     "Name"        = "${var.environment}-${local.target_group_app_name}"
     "ManagedBy"   = local.managed_by

variables.tf

@@ -11,7 +11,7 @@ variable "app_subdomain_name" {
   description = "The domain name for the public facing app. Application load balancer will be attached to this domain. Should be different for staging and production applications."
 }
 variable "alb_name" {
-  type = string
+  type        = string
   description = "Name of the application load balancer."
 }
 variable "alb_access_logs_prefix" {
@@ -23,34 +23,78 @@ variable "alb_access_logs_expiry_days" {
   description = "Number of days to retain application load balancer access logs."
 }
 variable "app_port" {
-  type = number
+  type        = number
   description = "The port number app is running on."
 }
 variable "alb_default_static_response" {
   type = object({
-    content_type = string
+    content_type         = string
     encoded_message_body = string
-    status_code = string
+    status_code          = string
   })
   description = "The default static response to return if no rules match in alb."
 }
 variable "vpc_id" {
-  type = string
+  type        = string
   description = "Identifier for AWS VPC where the resources will be created."
 }
 variable "http_https_ingress_sg_id" {
-  type = string
+  type        = string
   description = "Identifier for the security group allowing access to HTTP(80) and HTTPS(443) ingress. This is used for ingress traffic to load balancer."
 }
 variable "alb_subnets" {
-  type = list(string)
+  type        = list(string)
   description = "List of subnet identifiers to associate subnets to load balancer."
 }
 variable "alb_aws_account_arn" {
-  type = string
+  type        = string
   description = "AWS account ARN for the account containing load balancer."
 }
 variable "alb_access_logs_bucket_name" {
-  type = string
+  type        = string
   description = "S3 bucket name which will be used to store load balancer access logs. Prefix <var.environment> will be added. The bucket name should be unique globally."
 }
+variable "target_group_app_enabled" {
+  type        = bool
+  description = "Enable /Disable target health check."
+  default     = true
+}
+variable "target_group_app_healthy_threshold" {
+  type        = number
+  description = "Number of consecutive health checks successes required before considering an unhealthy target healthy."
+  default     = 3
+}
+variable "target_group_app_unhealthy_threshold" {
+  type        = number
+  description = "Number of consecutive health check failures required before considering the target unhealthy."
+  default     = 3
+}
+variable "target_group_app_interval" {
+  type        = number
+  description = "Approximate amount of time, in seconds, between health checks of an individual target."
+  default     = 30
+}
+variable "target_group_app_matcher" {
+  type        = string
+  description = "Response codes to use when checking for a healthy responses from a target."
+}
+variable "target_group_app_path" {
+  type        = string
+  description = "Destination for the health check request."
+}
+variable "target_group_app_port" {
+  type        = string
+  description = "Port to use to connect with the target."
+  default     = "traffic-port"
+}
+variable "target_group_app_protocol" {
+  type        = string
+  description = "Protocol to use to connect with the target."
+  default     = "HTTP"
+
+}
+variable "target_group_app_timeout" {
+  type        = number
+  description = "Amount of time, in seconds, during which no response means a failed health check."
+  default     = 5
+}