Configuring AWS ECS cluster to be load-balanced and auto-scaling behind a DNS

Question

I have a recently-Dockerized web app that I'm trying to get running in AWS ECS. I'm using Route 53 for the DNS.

Although I haven't set it up yet in Route 53, my plan is to create a DNS record of api.uat.myapp.example.com, and what I want is to have that domain name backed by an load-balanced, autoscaleable cluster of my containers living in ECS.

I'm in the ECS Container Network Configuration tab:

Press the "I believe!" button for a minute and let's pretend that I've already created the api.uat.myapp.example.com domain name in Route 53. What values/configs do I need to add here so that:

• When remote clients try to connect to api.uat.myapp.example.com they get routed to a load-balanced container running in my ECS cluster?; and
• That load-balanced ECS cluster is auto-scaling (once I figure out where I can configure auto-scaling properties, I'm sure I can figure out how to configure them!)

Answer 1

Your question is extremely broad. As such, this answer is likely overly generic to be of specific use, but hopefully will point you in the right direction.

First things first

You're misunderstanding the configuration you've taken a screenshot of. This is the network configuration within your container. So, what is your container's hostname, what other containers does it link to, what DNS Server do you want it to use, or alternatively, what specific other hosts should it know about... these are all optional, but may be required for your specific setup.

This has nothing to do with how your application scales.

Load Balancing

You need to decide on what type of load balancer you should use for your application, first. You then can point Route53 to that load balancer. Behind your load balancer will be your EC2 instances. For traffic to route to your containers, you need to make sure your EC2 ports map to the listening ports of your container. ECS can help with this.

Autoscaling

This happens in multiple ways.

You can do application autoscaling within ECS by having an ECS Service spin up and tear down containers on your EC2 instances.

You can have your Autoscaling Group scale up and down your EC2 instances -- but doing so, you'll need a way to automatically add those instances to your ECS Cluster.

Multiple scaling strategies exist. You'll need to decide for yourself which one is the most appropriate for your application, based on what metrics are most important to your scaling decisions.