Serverless

Question 1

1. What is required for AWS Lambda setup?

Answer 1

1. Runtime
2. Execution Role
3. Memory Allocation (128mb-10gb)
4. Timeout (15m max)
5. Trigger (S3? EventBridge?)
6. Optional: VPC

Question 2

How would you grant access to a DynamoDB table for a Lambda function that lives in a VPC?

Answer 2

You would ensure that the execution role has access to the relevant VPC endpoint using this permission AWSLambdaVPCAccessExecutionRole

Question 3

What are some common triggers for Lambda?

Answer 3

• EventBridge
• S3
• Kinesis

Question 4

What is the range for memory allocation for Lambda?

Answer 4

128mb-10gb

Question 5

How long can a lambda function run?

Answer 5

15 min Max. The goal is to minimize this.

Question 6

Why consider containers for apps?

Answer 6

• The container contains only the app with supporting files.
• No concerns about the underlying hardware, os, etc.
• Flexibility
• Portability
• Ease of Use

Question 7

What is a Dockerfile

Answer 7

• Contains - Commands and instructions to build an image.
• Image - Immutable file containing code, libraries, dependencies configuration for an application.
• Registry - Stored docker images for distribution
• Container - Running copy of a created image

Question 8

What is ECS? what is the open-source version?

Answer 8

• Elastic Container Service
• Helps you manage containers as the numbers scale
• Integrates with Elastic Load Balancer
• Integrates with IAM Roles
• It’s simple, but its AWS only (proprietary)
• The open-source version is EKS, Elastic Kubernetes Service.

Question 9

What if you want an open-source container system? What is the benefit?

Answer 9

• Kubernetes! EKS is the managed version of Kubernetes.
• Can be run on-premise and within AWS

Question 10

What is Fargate

Answer 10

• Serverless compute engine for containers

Question 11

Does Fargate work with EKS or ECS? Linux or Windows?

Answer 11

Both. Linux Only

Question 12

Why would you choose EC2 or Fargate?

Answer 12

• EC2
  
  1. You have to manage the servers
  2. Can take advantage of EC2 pricing
  3. Better for long-running containers
  4. Not used for containers
• Fargate
  
  1. No OS Access
  2. Pay only for what you use (think lambda)
  3. Only related to containers

Question 13

Why would you choose Fargate or Lambda?

Answer 13

• Fargate
  
  1. Best for consistent workloads
  2. More control by developers (containerization)
• Lambda
  
  1. Best for unpredictable workloads
  2. Great for a single function

Question 14

What is EventBridge

Answer 14

Its a serverless event bus that can trigger an action.

Question 15

What makes up an Event Bridge Rule

Answer 15

• A Pattern (Schedule or Trigger)
• A Trigger
  
  • Any API call that happens can kick of event bridge
• A Target (SNS, Lambda, etc)
• In short: things happen, Event bridge knows about it, it makes something else happen
• Think “If this then that”

Question 16

Why might you not want to use a serverless option?

Answer 16

• A monolithic server containing everything. → No
• A microservice -→ Yes

Question 17

What goes with Fargate, always?

Answer 17

• Containerization. ECS or EKS
• Fargate doesn’t operate as a standalone service.

Question 18

What’s the general process flow for a Dockerfile?

Answer 18

• Create the Dockerfile
• Build an image
• Upload the image to a repository
• Run it on a host

Question 19

What is Lambda@Edge?

Answer 19

Runs lambda functions in region closest to a user

Question 20

How should you associate roles to EC2 instances when using ECS

Answer 20

Associate the role with the ECS Task definition

https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task-iam-roles.html