AWS ECS Blue/Green Deployments

Recommendation: ALB-Native Weighted Routing (Preferred)

CodeDeploy adds IAM roles, appspec.json wiring, and a separate control plane. For most ECS blue/green needs, ALB weighted target groups achieve the same result with less setup.

How it works

Define two target groups (blue/green) and a single listener rule that splits traffic by weight:

resource "aws_lb_target_group" "blue" {
  name        = "myapp-blue"
  port        = 8080
  protocol    = "HTTP"
  vpc_id      = var.vpc_id
  target_type = "ip"