Use only one target group for the listeners to fix sticky sessions

[jvisker]

From https://docs.aws.amazon.com/elasticloadbalancing/latest/application/sticky-sessions.html:
"If you have a forward action with multiple target groups, and sticky sessions are enabled for one or more of the target groups, you must enable stickiness at the target group level."

When we added a second target group to the listeners it broke because it would require their to get stickiness to the target group set on the listener. I considered setting the group sticky session, but that would mess up blue green deployments because traffic would stick to the target groups which doesn't make sense with blue green deployments.

[github-actions]

Terraform Plan:

will create 26 resources:

• aws_efs_file_system - my_efs
• aws_alb - alb
• aws_alb_listener - http_to_https
• aws_alb_listener - https
• aws_alb_listener - test_listener
• aws_alb_target_group - blue
• aws_alb_target_group - green
• aws_cloudwatch_log_group - container_log_group
• aws_cloudwatch_log_group - xray_log_group
• aws_codedeploy_app - app
• aws_codedeploy_deployment_group - deploymentgroup
• aws_ecs_cluster - new_cluster
• aws_ecs_service - service
• aws_ecs_task_definition - task_def
• aws_iam_policy - secrets_access
• aws_iam_role - task_execution_role
• aws_iam_role - task_role
• aws_iam_role_policy_attachment - secret_task_policy_attach
• aws_iam_role_policy_attachment - secrets_policy_attach
• aws_iam_role_policy_attachment - task_execution_policy_attach
• aws_iam_role_policy_attachment - xray_task_policy_attach
• aws_route53_record - a_record
• aws_route53_record - aaaa_record
• aws_security_group - alb-sg
• aws_security_group - fargate_service_sg
• local_file - appspec_json

see details

[yoshutch]

as long as it looks like it works 😅