title: Blue Green Deployment with AWS ECS
body: <p>We are using ECS Fargate containers to deploy all of our services (~10) and want to follow Blue/Green Deployment.</p>
  <p>We have deployed all the services under BLUE flag where target groups are pointing to the services.<br />
  In CICD, New Target groups are created and having slightly different forward rules to allow testing without any issue.<br />
  Now, my System is running with 2 kind of target groups, services and task definition -</p>
  <ul>
  <li><strong>tg_blue, service_blue, task_blue →</strong> pointing to old containers and serving live traffic</li>
  <li><strong>tg_green, service_green, task_green →</strong> pointing to new containers and do not have any traffic.<br />
  All above steps are done in Terraform.</li>
  </ul>
  <p>Now, I want to switch the traffic and here I am stuck, How to Switch the Traffic and How the next Deployment will look like?</p>