ECS, ECR and Fargate

Question 1

Amazon ECS

Answer 1

Simplifies process of running, managing and scaling containerised applications by providing manager service that takes care of it for you

Question 2

ECS - EC2 Launch Type

Answer 2

Containerised applications run on a cluster of EC2 instances that you manage

Question 3

ECS - Fargate Launch Type

Answer 3

Provides a serverless experience where you don’t need to manage instances; AWS automatically provisions and scales the compute resources needed for your tasks

Question 4

EC2 Instance Profile

Answer 4

Provides permissions to the EC2 instances themselves, EC2 launch type only

Question 5

ECS Task Role

Answer 5

Allows each task to have a specific role, defined in the task definition

Question 6

Amazon EFS

Answer 6

Elastic file system, share data across multiple compute instances, works for EC2 and Fargate launch types

Question 7

Can Amazon S3 be mounted as a file system for ECS?

Answer 7

No

Question 8

ECS Auto Scaling uses AWS Application Scaling which is based on…

Answer 8

• ECS service avg CPU utilisation
• ECS service avg Memory utilisation
• ALB request count per target

Question 9

Target tracking

Answer 9

Scale based on target value for specific CloudWatch metric

Question 10

Step scaling

Answer 10

Scale based on specified CloudWatch Alarm

Question 11

Scheduled scaling

Answer 11

Scale based on specified date/time for predictable changes

Question 12

ECS service auto scaling is done at the ______ level whereas EC2 auto scaling is done at the ______ level

Answer 12

task, instance

Question 13

ECS Cluster Capacity PRovider

Answer 13

Used to automatically provision and scale infrastructure for your ECS tasks (preferred)

Question 14

ECS Rolling updates

Answer 14

When updating from v1 to v2, can control how many tasks can be started and stopped and in which order (set minimum and maximum percentage of healthy instances)

Question 15

Dynamic Host Port Mapping

Answer 15

ALB finds the right port on your EC2 instances for you, occurs when you define only the container port in the task definition

Question 16

Load balancing in Fargate

Answer 16

Each task has a unique private IP, only define the container port (host port is not applicable)

Question 17

Where do you define IAM role for ECS task?

Answer 17

In the task definition

Question 18

ECS Environment Variables

Answer 18

hardcoded (eg. URLs), SSM parameter store, secrets manager, or load directly from amazon s3 bucket

Question 19

ECS Data Volumes / Bind Mounts

Answer 19

Share data between multiple containers in the same Task Definition (works for EC2 and fargate tasks)

Question 20

Sidecar container pattern

Answer 20

Sidecar container is used to send metrics/logs to other destinations (needs to read from shared storage)

Question 21

Task roles

Answer 21

Allow container to make API calls to AWS services

Question 22

What is an essential container?

Answer 22

If the container fails or is killed, all tasks will be stopped

Question 23

ECS Task Placement

Answer 23

When a task of type EC2 is launched, ECS must determine where to place it with constraints of CPU, memory and available port (only for ECS with EC2, not fargate)

Question 24

Binpack Task Placement Strategy

Answer 24

Place tasks based on the least available amount of CPU or memory, minimises number of instances in use (saves money)

Question 25

Random Task Placement Strategy

Answer 25

Place the task randomly

Question 26

Spread Task Placement Strategy

Answer 26

Place the task evenly across specified AZs

Question 27

ECS Task Placement Constraints

Answer 27

distinctInstance (place each task on a different container instance) and memberOf (places task on instances that satisfy an expression eg. t2 ec2 instance)

Question 28

Amazon ECR (Elastic container registry)

Answer 28

Store and manage Docker images on AWS, fully integrated with ECS, access controlled through IAM, pull Docker images

Question 29

AWS Copilot

Answer 29

CLI tool to provision required infra for containerised apps, run your apps on AWS AppRunner, ECS and Fargate

Question 30

Amazon EKS (Amazon Elastic Kubernetes Service)

Answer 30

Way to launch managed Kubernetes clusters on AWS, alternative to ECS - similar goal but different API

Question 31

EKS use case

Answer 31

If your company is already using Kubernetes on-premises or in another cloud and want to migrate to AWS using Kubernetes

Question 32

EKS Managed Node Groups

Answer 32

Creates and manages EC2 instances for you, nodes are part of ASG managed by EKS

Question 33

EKS Self-Managed nodes

Answer 33

Nodes created by you and registered to EKS cluster and managed by an ASG, can use prebuilt AMI (Amazon EKS Optimised AMI)

Question 34

EKS Data Volumes

Answer 34

Need to specify StorageClass manifest on your EKS cluster, leverages Container Storage Interface (CSI) compliant dirver, supports Amazon EBS, EFS, and EFx

Question 35

You have a Classic ECS cluster that you want to enable IAM roles for your ECS tasks so that they can make API requests to AWS services. Which ECS configuration option should you enable in /etc/ecs/ecs.config?

Answer 35

ECS_ENABLE_TASK_IAM_ROLE