chore: support blue-green deployment

Author: lycbrian

CHANGELOG.md

@@ -1,6 +1,15 @@
 # Change Log
 
+## [v1.4.0] - 2025-08-20
+
+### Added
+
+- Support blue-green deployment
+    - var: is_enable_blue_green_deployment
+    - resource:  aws_lb_target_group.green
+
 ## [v1.3.1] - 2025-04-09
+
 ### Added
 
 - lifecycle create_before_destroy for aws_lb_target_group

examples/terraform-test/main.tf

@@ -177,5 +177,8 @@ module "api_service" {
     }
   }
 
+  # Blue-Green Deployment
+  is_enable_blue_green_deployment = true
+
   tags = var.custom_tags
 }

main.tf

@@ -149,6 +149,34 @@ resource "aws_lb_target_group" "this" {
     create_before_destroy = true
   }
 
+}
+
+resource "aws_lb_target_group" "green" {
+  count = local.is_create_target_group && var.is_enable_blue_green_deployment ? 1 : 0
+
+  name = format("%s-green-tg", substr(local.container_target_group_object.name, 0, min(29, length(local.container_target_group_object.name))))
+
+  port                 = lookup(local.container_target_group_object, "port_mappings", null)[0].container_port
+  protocol             = lookup(local.container_target_group_object, "port_mappings", null)[0].container_port == 443 ? "HTTPS" : "HTTP"
+  vpc_id               = var.vpc_id
+  target_type          = "ip"
+  deregistration_delay = var.target_group_deregistration_delay
+
+  health_check {
+    interval            = lookup(var.health_check, "interval", null)
+    path                = lookup(var.health_check, "path", null)
+    timeout             = lookup(var.health_check, "timeout", null)
+    healthy_threshold   = lookup(var.health_check, "healthy_threshold", null)
+    unhealthy_threshold = lookup(var.health_check, "unhealthy_threshold", null)
+    matcher             = lookup(var.health_check, "matcher", null)
+  }
+
+  tags = merge(local.tags, { "Name" = format("%s-tg", substr(local.container_target_group_object.name, 0, min(29, length(local.container_target_group_object.name)))) })
+
+  lifecycle {
+    create_before_destroy = true
+  }
+
 }
 /* ------------------------------ Listener Rule ----------------------------- */
 resource "aws_lb_listener_rule" "this" {

variables.tf

@@ -305,3 +305,13 @@ variable "container" {
   type        = any
   default     = {}
 }
+
+/* -------------------------------------------------------------------------- */
+/*                                Blue-Green Deployment                       */
+/* -------------------------------------------------------------------------- */
+variable "is_enable_blue_green_deployment" {
+  description = "Whether the service enable blue-green deployment"
+  type        = bool
+  default     = false
+}
+