AWS ECS

Amazon Elastic Container Service #

AWS ECS (Amazon Elastic Container Service) is a fully managed container orchestration service for deploying, managing, and scaling containerized applications using Docker containers. ECS allows users to easily run containerized applications on a cluster of EC2 instances or with AWS Fargate, handling tasks like scheduling, scaling, and load balancing.

Key concepts #

• Cluster: a logical group of tasks and services and of the capacity that runs them.
• Task definition: the blueprint of an application: the container images (from ECR or Docker Hub), CPU and memory, ports, environment variables, logging and the IAM roles.
• Task: a running instance of a task definition. Service: keeps the desired number of tasks running and can register them in a load balancer.
• Capacity: AWS Fargate (serverless, no instances to manage) or EC2 instances in an Auto Scaling group.
• Networking: the awsvpc mode gives each task its own network interface in a subnet of a VPC, protected by security groups.

Pricing #

ECS has no additional charge: you pay for the EC2 instances or the Fargate resources that run the tasks.

With Terraform #

The resources are aws_ecs_cluster, aws_ecs_task_definition, aws_ecs_service and aws_ecs_cluster_capacity_providers.

See also: AWS EKS, the managed Kubernetes alternative.

See tutorials:

• How to Deploy Containers in AWS ECS with Terraform and Fargate