API Gateway

Question 1

API Gateway

Answer 1

• serverless publicly accessible to proxy requests to things ..lambda for example
  
  • websocket protocol - real time streaming
• HTTP integration - expose internal http endpoints to utilize rate limiting, caching, api keys, etc.

Question 2

API gateway endpoint types

Answer 2

• edge optimized - default - for global clients
• regional - for clients in one region
• private - only within your own VPC using ENI (VPC endpoints)

Question 3

API gateway auth

Answer 3

• IAM roles (useful for internal apps)
• cognito (mobile)
• custom authorizer (lambda)
• HTTPS custom domain name through aws cert manager
  
  • must setup CNAME alias in R53 to point to api gateway
• cross account access - use a resource policy and and sigv4

Question 4

API gateway deployment stages

Answer 4

• MUST do deployment stage for changes to be active
• common to point gateway stage to lambda alias which points to specific lambda version
• cache, waf, logs, tracing settings are at the DEPLOYMENT level

Question 5

API gateway integration types

Answer 5

• mock - return a response without sending the request to the backend
• http / aws lambda
  
  • configure integration request/response
  • setup data mapping using mapping templates for request & response
    
    • json to xml
• aws_proxy (lambda proxy)
  
  • no modification of request
  • lambda is responsible for handling request as is
• http_proxy
  
  • gateway to ALB

Question 6

api gateway throttling

Answer 6

• default - 10k rps across all API
  
  • soft limit
• can set stage and method limits
• just like lambda concurrency, one API that is overloaded, if not limited causes other APIs to throttle

Question 7

API Gateway CORS

Answer 7

• cross origin resource sharing
• can enable in api gateway for only non-proxy endpoints

Question 8

rest vs http

Answer 8

REST APIs support more features than HTTP APIs, while HTTP APIs are designed with minimal features so that they can be offered at a lower price. Choose REST APIs if you need features such as API keys, per-client throttling, request validation, AWS WAF integration, or private API endpoints.

Question 9

Promoting test stage to prod stage

Answer 9

Update stage variable value from the stage name of test to that of prod (because stage name is included in url) or redeploying the API to the prod stage