Chloe McAree (McAteer)
Published on

AWS ECS, Fargate, EKS & ECR


This is part of a blog series giving a high level overview of the different services examined on the AWS Solution Architect Associate exam, to view the whole series click here.

Elastic Container Service (ECS) Summary

ECS logo

  • Highly scalable managed container orchestration service.

  • Allows you to launch, run, stop and manage containers within a cluster.

  • Can be use to mange EC2 or Fargate instances.

  • Defines rules for CPU and memory utilisation and allows you to specify a specific number of tasks to run simultaneously.

  • Containers are launched within a VPC so can be secured with security groups and network ALCs.

  • Highly available as containers can be ran across multiple Availability Zones within a region.

ECS Components

Container images — Contains everything you application needs to run e.g. code, runtime, libraries etc.

Task definition → Defines your application by describing one or more containers, it is in JSON format, similar concept to a Dockerfile.

Task → Single running copy of any container defined by a task definition.

Cluster → Logical collection of tasks or services.

Container agent — there is one in every container and it is used to send information about the current running tasks and current utilisation to ECS.

Container definition → used inside a task definition, describes the individual containers a task uses. Controls CPU & memory allocation

Registry → Storage for containers e.g. ECR or Docker Hub.

Fargate Summary

  • Serverless compute engine for containers — works with ECS and EKS

  • Provides the right sized compute capacity on demand for containers and eliminates needs to provision and manage servers.

  • Secure as every individual task or pod is ran isolated in its one kernel runtime environment — they don’t share CPU, memory or storage.

  • Can use CloudWatch for observability to monitor container insights.

  • If your applications require broader customisation or require GPUs, Fargate might not be be option for you — as it currently does not support GPUs.

Elastic Kubernetes Service (EKS) Summary

  • EKS is a managed service that allows you to run Kubernetes on AWS.

  • Kubernetes is open source and lets you deploy & manage containerised applications at scale

  • EKS can automatically detect and replace unhealthy instances

  • EKS also provides automatic patching and version updates.

Elastic Container Registory (ECR) Summary

  • Fully managed service for storing, manage and deploy container images.

  • Integrates with ECS, EKS and Lambda.

  • ECR also integrates with IAM which can allow resource level control of repositories.

  • Pay for data storage and data transfer.