API (Application Programming Interface) Creation and Management is essential for the AWS Certified Solutions Architect – Associate certification (SAA-C03). It involves configuring front-end and back-end interfaces for an application, securing and managing APIs, routing requests, and handling responses.

One of the prime examples of API management service provided by AWS is Amazon API Gateway. It is a fully managed service that makes it easier for developers to create, deploy, and manage APIs at scale on AWS.

Table of Contents

Amazon API Gateway

Amazon API Gateway allows developers to define the HTTP endpoints and the corresponding integration with backend, authorization, and access control policies.

Features of Amazon API Gateway

  • RESTful APIs: Amazon API Gateway allows you to build RESTful APIs and WebSocket APIs that enable real-time two-way communication.
  • Integration: APIs built on the Amazon API Gateway can be integrated with AWS Lambda, Amazon DynamoDB, Amazon S3, and other AWS services.
  • Security: APIs can be secured with AWS Identity and Access Management (IAM) and Amazon Cognito.
  • Rate Limiting: The service permits setting a rate limit for each user.
  • SDK Generation: Developers can generate client SDKs for a number of platforms which include Javascript, iOS, and Android.
  • Monitoring: Integrated with Amazon Cloudwatch, users can monitor API usage.
  • Transformation: API Gateway can transform and route HTTP requests to different endpoints.

Working with API Gateway

To create a REST API in Amazon API Gateway, developers would typically follow these steps:

  • Define an API (container)
  • Define Resources and nested Resources (URL paths)
  • For each Resource:
    • Define one or more HTTP methods (verbs)
    • For each HTTP method:
      • Choose the backend: it could be a Lambda function, an HTTP endpoint, an AWS service, etc.
      • Set request and response data transformations
      • Choose the type of authorization: IAM, Lambda, Cognito User Pool, etc.

Representing a sample configuration in a table:

Resource HTTP Method Backend Data Transformation Authorization
/users GET Lambda JSON to XML IAM
/users POST HTTP endpoint XML to JSON Lambda

This table shows that for the “users” resource, we have two HTTP methods established, GET and POST, mapped to different backends, and set their request response data transformations and types of authorization respectively.

The AWS Certified Solutions Architect – Associate (SAA-C03) exam evaluates a candidate’s ability to effectively demonstrate knowledge of how to architect and deploy secure and robust applications on AWS technologies, including effective API creation and management. Developing a keen understanding of services like Amazon API Gateway, and how to effectively deploy and manage APIs on AWS, is vital for success in the AWS certification. Be sure to be familiar with the wide set of AWS services and how they integrate with API management. Finally, remember that practice is key – nothing beats hands-on experience when it comes to mastering AWS technologies.

Practice Test

True or False: Amazon API Gateway is a fully managed service that allows developers to create, manage, and deploy APIs at scale.

  • True
  • False

Answer: True

Explanation: Amazon API Gateway indeed provides developers with the tools needed to effectively manage and scale APIs, including traffic management, data transformation, and more.

Which of the following are capabilities of Amazon API Gateway?

  • A. Traffic management
  • B. API version management
  • C. API key management
  • D. Data transformation
  • E. All of the above

Answer: E. All of the above

Explanation: Amazon API Gateway provides a suite of tools for API management, including traffic and API key management, API version management, and data transformations.

True or False: REST APIs can be created using the HTTP protocol.

  • True
  • False

Answer: True

Explanation: One of the key principles of a REST API is that it uses HTTP methods to map Create, Read, Update and Delete (CRUD) operations to HTTP requests.

Which AWS service would you use to deploy a serverless application whose functions are triggered by events?

  • A. AWS Lambda
  • B. Amazon S3
  • C. AWS EC2
  • D. Amazon Redshift

Answer: A. AWS Lambda

Explanation: AWS Lambda allows you to run your code without provisioning or managing servers and can be triggered by events.

True or False: Amazon API Gateway supports WebSocket APIs.

  • True
  • False

Answer: True

Explanation: Amazon API Gateway also supports WebSocket APIs which enable you to have real-time, two-way communication with your clients.

Which of the following is a primary component of an API?

  • A. Interface
  • B. Database
  • C. API Gateway
  • D. Both A and C

Answer: D. Both A and C

Explanation: An API consists of an interface that specifies how it communicates with digital products, and the API Gateway which is a server that acts as an API front-end.

Using Amazon API Gateway, you can create ____

  • A. REST APIs
  • B. SOAP APIs
  • C. GraphQL APIs
  • D. All of the above

Answer: D. All of the above

Explanation: Amazon API Gateway supports creation of RESTful, SOAP and GraphQL APIs.

True or False: REST APIs are stateless; this means that the server does not keep any data required to fulfill requests from a client.

  • True
  • False

Answer: True

Explanation: Being stateless is one of the essential constraints of the REST architectural style. It means that the server should not store anything about the latest HTTP request the client made.

What does API stand for?

  • A. Application Programming Induction
  • B. Application Programming Interface
  • C. Applied Programming Interface
  • D. Applied Programming Induction

Answer: B. Application Programming Interface

Explanation: API is an acronym for Application Programming Interface. It is a set of rules that lets programs talk to each other.

True or False: Amazon API Gateway is completely serverless.

  • True
  • False

Answer: True

Explanation: Amazon API Gateway is an AWS managed service that is serverless and does not require the user to manage any infrastructure.

Interview Questions

What is Amazon API Gateway?

Amazon API Gateway is a fully managed service that makes it easy for developers to create, publish, maintain, monitor, and secure APIs at any scale.

What is a REST API?

REST, or REpresentational State Transfer, is a architectural style for developing web services. A REST API, or RESTful API, uses HTTP methods to retrieve and update data and is based on representational state transfer technology.

What is throttling in API Gateway?

Throttling is a process used to limit the number of requests that can be made to an API Gateway within a given time period. Throttling helps to manage the performance and scalability of the endpoints.

What are the key benefits of Amazon API Gateway?

The benefits of Amazon API Gateway include allowing developers to build and run APIs without managing servers, handling traffic management, authorization and access control, monitoring, and API version management.

Can you enable caching in Amazon API Gateway?

Yes, API Gateway provides an optional caching capability to cache your endpoint’s responses. With caching, you can reduce the number of calls made to your endpoint and also improve the latency of requests to your API.

What does it mean by API versioning in API Gateway?

API versioning in API Gateway refers to the concept of making changes or updates to an API without impacting the existing client applications that are using the previous version of API.

What are the components of API Gateway?

The key components of API Gateway include resources, methods, integrations, stages, deployment, models, and authorizers.

What is the role of AWS Lambda with API Gateway?

AWS Lambda can be used as an integration backend with API Gateway. This means API Gateway routes the incoming request to the respective AWS Lambda function and returns the function’s response to the requester.

What is a Stage in API Gateway?

A Stage in API Gateway is essentially a named reference to a deployment, a time-point at which an API is deployed.

How can you secure APIs in API Gateway?

APIs in API Gateway can be secured using various methods like AWS IAM roles and policies, Lambda authorizers, Amazon Cognito user pools, client certificate authentication and resource policies.

What are API Gateway resource policies?

Resource policies are JSON policy documents that you attach to an API to control whether a specified principal (user or application) can invoke the API. They provide more granular control over access based on context such as IP address or source VPC.

What are the different types of endpoints offered by API Gateway?

API Gateway offers three types of endpoints: Edge-optimized endpoints for global clients, Regional endpoints for clients in the same geographical region as the API, and Private endpoints for clients accessing from the same Amazon VPC.

What types of APIs does Amazon API Gateway support?

Amazon API Gateway supports RESTful APIs and WebSocket APIs.

Can API Gateway handle multiple versions of a REST API?

Yes, Amazon API Gateway supports multiple versions of the same API through a feature known as API versioning.

How does API Gateway integrate with other AWS services?

API Gateway can integrate directly with several other AWS services, serving as a ‘front door’ to applications running on services like AWS Lambda, Amazon EC2, or Amazon ECS.

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