AWS has introduced integrated service discovery to Amazon ECS. This allows ECS to automatically register itself with a DNS name in Amazon Route 53. Not only is the DNS name predictable and friendly, the service will also keep Route 53 hosted zone updated as necessary. This lets other services lookup where they need to make connections, depending on the state of each service.
Formerly, one had to configure traditional ways of service discovery like consul that need provisioning and added infrastructure, or perhaps agents installed in containers or instances. You would need to run your own discovery system or connect each service to a load balancer. Starting now, however, you may configure automated service discovery for containerized services using ECS console, AWS CLI or the ECS API.
Amazon ECS Discovery communicates with Amazon Route 53 Sevice Register and Auto naming APIs. When we request Route 53 for something, it returns a set of possible IPs that may fulfill our request. If the application being connected to exposes dynamic ports, the application making the call could easily query the SRV record for more data.
This service is currently available in US East (N. Virginia), US East (Ohio), US West (Oregon), and EU (Ireland). When using this service, you pay only for the resources consumed by Route 53 including the namespaces created and the number of lookups made by your services. Check out this document for more pricing information.