By configuring your Docker containers to talk to a custom DNS server, you gain more control over how your container look up other services – database, other microservices, etc.,

It turns out Docker networking isn’t completely straight forward. On Linux you can:

1. Run a DNS server locally, either dnsmasq or devdns
2. Run your container with --dns 172.17.0.1, the magic IP where your host machine is located
3. Configure dnsmasq from step 1 via /etc/hosts

Sadly, none of it was easy. The entire thing probably took me three hours.

I still find it hard to believe how easy it is to run your own infrastructure in the cloud.

Running a Docker registry is as simple as adding a few lines of code to your Terraform configuration.

	resource "aws_ecr_repository" "foo" {
	  name                 = "bar"
	  image_tag_mutability = "MUTABLE"

	  image_scanning_configuration {
		scan_on_push = true
	  }
	}

When deployed, this create an registry where you can manage multiple Docker repositories. You can upload a Docker image to be used in your private ECS cluster: