AWS Container: Docker, ECS and EKS

Posted by Hardwork đẹp trai on February 06, 2024 · 7 mins read

Container Section

  • Docker is a software development platform to deploy apps
  • Apps are packaged in containers that can be run on any OS
  • Apps run the same, regardless of where they’re run
    • Any machine
    • No compatibility issues
    • Predictable behavior
    • Less work
    • Easier to maintain and deploy
    • Works with any language, any OS, any technology
  • Use cases: microservices architecture, lift and shift apps from on-premises to the AWS cloud,…

    Where are Docker images stored?

  • Docker images are stored in Docker Repositories
  • Docker Hub (https://hub.docker.com)
    • public repossitory
    • Find base images for many technologies or OS (e.g., Ubuntu, MySQL, …
  • Amazon ECR (Amazon Elastic Container Registry)
    • Private repository
    • Public repository (Amazon ECR Public Gallery https://gallery.ecr.aws)

      Docker vs. Virtual Machines

  • Docker is ”sort of ” a virtualization technology, but not exactly
  • Resources are shared with the host => many containers on one server

    Getting Started with Docker

    Docker Containers Management on AWS

  • Amazon Elastic Container Service (Amazon ECS)
    • Amazon’s own container platform
  • Amazon Elastic Kubernetes Service (Amazon EKS)
    • Amazon’s managed Kubernetes (open source)
  • AWS Fargate
    • Amazon’s own Serverless container platform
    • Works with ECS and with EKS
  • Amazon ECR
    • Store container images

      Amazon ECS - EC2 Launch Type

  • ECS = Elastic Container Service
  • Launch Docker containers on AWS = Launch ECS Tasks on ECS Clusters
  • EC2 Launch Type: you must provision & maintain the infrastructure (the EC2 instances)
  • Each Ec2 Instance must run the ECS agent to register in the ECS Cluster
  • AWS takes care of starting / stoping containers

    Amazon ECS – Fargate Launch Type

  • Launch Docker containers on AWS
  • You do not provision the infrastructure (no EC2 instances to manage)
  • It’s all Serverless!
  • You just create task definitions
  • AWS just runs ECS Tasks for you based on the CPU / RAM you need
  • To scale, just increase the number of tasks. Simple - no more EC2 instances

    Amazon ECS – IAM Roles for ECS

  • EC2 Instance Profile (EC2 Launch Type only):
    • Used by the ECS agent
    • Makes API calls to ECS service
    • Send container logs to CloudWatch Logs
    • Pull Dockerimage from ECR
    • Rederence sensitive data in secrets manager or SSM Parameter Store
  • ECS Task Role
    • Allows each task to have a specific role
    • Use different roles for the different ECS Services you run
    • Task Role is defined in the task definition

      Amazon ECS – Load Balancer Integrations

  • Application Load Balancer supported and works for most use cases
  • Network Load Balancer recommended only for high throughput / high performance use cases, or to pair it with AWS Private Link
  • Elastic Load Balancer supported but not recommended (no advanced features – no Fargate)

    Amazon ECS – Data Volumes (EFS)

  • Mount EFS file systems onto ECS tasks
  • Works for both EC2 and Fargate launch types
  • Tasks running in any AZ will share the same data in the EFS file system
  • Fargate + EFS = Serverless
  • Use cases: persistent multi-AZ shared storage for your containers
  • Note:
    • FSx For Lustre is not supported
    • Amazon S3 cannot be mounted as a file system

      ECS Service Auto Scaling

  • Automatically increase/decrease the desired number of ECS tasks
  • Amazon ECS Auto Scaling uses AWS Application Auto Scaling
    • ECS Service Average CPU Utilization
    • ECS Service Average Memory Utilization - Scale on RAM
    • ALB Request Count Per Target – metric coming from the ALB
  • Target Tracking – scale based on target value for a specific CloudWatch metric
  • Step Scaling – scale based on a specified CloudWatch Alarm
  • Scheduled Scaling – scale based on a specified date/time (predictable changes)
  • ECS Service Auto Scaling (task level) ≠ EC2 Auto Scaling (EC2 instance level)
  • Fargate Auto Scaling is much easier to setup (because Serverless)

    EC2 Launch Type – Auto Scaling EC2 Instances

  • Accommodate ECS Service Scaling by adding underlying EC2 Instances
  • Auto Scaling Group Scaling
    • Scale your ASG based on CPU Utilization
    • Add EC2 instances over time
  • ECS Cluster Capacity Provider
    • Used to automatically provision and scale the infrastructure for your ECS Tasks
    • Capacity Provider paired with an Auto Scaling Group
    • Add EC2 Instances when you’re missing capacity (CPU, RAM…)

      ECS Scaling – Service CPU Usage Example

      ECS Rolling Updates

  • When updating from v1 to v2, we can control how many tasks can be started and stopped, and in which order
  • ECS Rolling Update – Min 50%, Max 100%
  • ECS Rolling Update – Min 100%, Max 150%

    ECS tasks invoked by Event Bridge

    ECS tasks invoked by Event Bridge Schedule

    ECS – SQS Queue Example

    Amazon ECR

  • ECR = Elastic Container Registry
  • Store and manage Docker images on AWS
  • Private and Public repository (Amazon ECR Public Gallery https://gallery.ecr.aws)
  • Fully integrated with ECS, backed by Amazon S3
  • Access is controlled through IAM (permission errors => policy)
  • Supports image vulnerability scanning, versioning, image tags, image lifecycle, …

    Amazon EKS Overview

  • Amazon EKS = Amazon Elastic Kubernetes Service
  • It is a way to launch managed Kubernetes clusters on AWS
  • Kubernetes is an open-source system for automatic deployment, scaling and management of containerized (usually Docker) application
  • It’s an alternative to ECS, similar goal but different API
  • EKS supports EC2 if you want to deploy worker nodes or Fargate to deploy serverless containers
  • Use case: if your company is already using Kubernetes on-premises or in another cloud, and wants to migrate to AWS using Kubernetes
  • Kubernetes is cloud-agnostic (can be used in any cloud – Azure, GCP…)
  • For multiple regions, deploy one EKS cluster per region

    Amazon EKS - Diagram

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