Mobile Services | Amazon API Gateway Flashcards
What is Amazon API Gateway?
General
Amazon API Gateway | Mobile Services
Amazon API Gateway is a fully managed service that makes it easy for developers to publish, maintain, monitor, and secure APIs at any scale. With a few clicks in the AWS Management Console, you can create an API that acts as a “front door” for applications to access data, business logic, or functionality from your back-end services, such as applications running on Amazon Elastic Compute Cloud (Amazon EC2), code running on AWS Lambda, or any web application. Amazon API Gateway handles all of the tasks involved in accepting and processing up to hundreds of thousands of concurrent API calls, including traffic management, authorization and access control, monitoring, and API version management. Amazon API Gateway has no minimum fees or startup costs. You pay only for the API calls you receive and the amount of data transferred out.
Why use Amazon API Gateway?
General
Amazon API Gateway | Mobile Services
Amazon API Gateway provides developers with a simple, flexible, fully managed, pay-as-you-go service that handles all aspects of creating and operating robust APIs for application back ends. With Amazon API Gateway, you can launch new services faster and with reduced investment so you can focus on building your core business services. Amazon API Gateway was built to help you with several aspects of creating and managing APIs:
1) Metering. API Gateway helps you define plans that meter and restrict third-party developer access to your APIs. You can define a set of plans, configure throttling, and quota limits on a per API key basis. API Gateway automatically meters traffic to your APIs and lets you extract utilization data for each API key.
2) Security. API Gateway provides you with multiple tools to authorize access to your APIs and control service operation access. Amazon API Gateway allows you to leverage AWS administration and security tools, such as AWS Identity and Access Management (IAM) and Amazon Cognito, to authorize access to your APIs. Amazon API Gateway can verify signed API calls on your behalf using the same methodology AWS uses for its own APIs. Using custom authorizers written as AWS Lambda functions, API Gateway can also help you verify incoming bearer tokens, removing authorization concerns from your backend code.
3) Resiliency. Amazon API Gateway helps you manage traffic with throttling so that backend operations can withstand traffic spikes. Amazon API Gateway also helps you improve the performance of your APIs and the latency your end users experience by caching the output of API calls to avoid calling your backend every time.
4) Operations Monitoring. After an API is published and in use, API Gateway provides you with a metrics dashboard to monitor calls to your services. The Amazon API Gateway dashboard, through integration with Amazon CloudWatch, provides you with backend performance metrics covering API calls, latency data and error rates. You can enable detailed metrics for each method in your APIs and also receive error, access or debug logs in CloudWatch Logs.
5) Lifecycle Management. After an API has been published, you often need to build and test new versions that enhance or add new functionality. Amazon API Gateway lets you operate multiple API versions and multiple stages for each version simultaneously so that existing applications can continue to call previous versions after new API versions are published.
6) Designed for Developers. Amazon API Gateway allows you to quickly create APIs and assign static content for their responses to reduce cross-team development effort and time-to-market for your applications. Teams who depend on your APIs can begin development while you build your backend processes.
How do I get started with Amazon API Gateway?
General
Amazon API Gateway | Mobile Services
You can quickly and easily create a custom API using Amazon API Gateway. For a simple “Hello World” example, follow these steps:
- Go to the Amazon API Gateway console.
- Select an existing REST API or create a new one by entering a name for the API.
- On the REST API tree view, click “Create Resource”.
- Choose a name for your resource, such as “cars”.
- With the new resource selected, click the button to create a new method and select the HTTP verb associated with the method (for example, GET).
- Select the integration type (for example, HTTP Proxy), and enter the URL the Amazon API Gateway should call.
- Define how requests and responses are transformed using a mapping template, or accept the default settings to pass all of the request and response data through without applying any transformation.
- Configure the method’s security settings.
- Deploy your new API to a stage.
- From the Stage management page, set up caching and throttling.
- On the Client Platforms tab in the Amazon API Gateway console, click the button to download the Android, iOS SDK, or JavaScript library that contains helper methods to call your sayHello operation. The SDK library makes calling your APIs similar to calling a local method. The client SDK automatically handles retries, informing the developer of network or other fault conditions. The SDK library includes the logic necessary to authenticate the client application to your APIs.
- Integrate the downloaded SDK into your mobile application. Write the code to invoke your custom API. For example, to invoke the getCar(int carId) API in an iOS application:
–(void)getSampleCar
{
NSString *response = [MyServiceClient getCar:1323];
NSLog( @”Response was [%@]”, response );
}
- Run your application.
Can I create HTTPS endpoints?
General
Amazon API Gateway | Mobile Services
Yes, all of the APIs created with Amazon API Gateway expose HTTPS endpoints only. Amazon API Gateway does not support unencrypted (HTTP) endpoints. By default, Amazon API Gateway assigns an internal domain to the API that automatically uses the Amazon API Gateway certificate. When configuring your APIs to run under a custom domain name, you can provide your own certificate for the domain.
What data types can I use with Amazon API Gateway?
General
Amazon API Gateway | Mobile Services
APIs built on Amazon API Gateway can accept any payloads sent over HTTP. Typical data formats include JSON, XML, query string parameters, and request headers. You can declare any content type for your API’s responses, and then use the transform templates to change the back-end response into your desired format.
With what backends can Amazon API Gateway communicate?
General
Amazon API Gateway | Mobile Services
Amazon API Gateway can execute AWS Lambda functions in your account, start AWS Step Functions state machines, or call HTTP endpoints hosted on AWS Elastic Beanstalk, Amazon EC2, and also non-AWS hosted HTTP based operations that are accessible via the public Internet. API Gateway also allows you to specify a mapping template to generate static content to be returned, helping you mock your APIs before the backend is ready. You can also integrate API Gateway with other AWS services directly – for example, you could expose an API method in API Gateway that sends data directly to Amazon Kinesis.
For which client platforms can Amazon API Gateway generate SDKs?
General
Amazon API Gateway | Mobile Services
API Gateway generates custom SDKs for mobile app development with Android and iOS, and for web app development with JavaScript. Once an API and its models are defined in API Gateway, you can use the AWS console or the API Gateway APIs to generate and download a client SDK.
In which AWS regions is Amazon API Gateway available?
General
Amazon API Gateway | Mobile Services
Please refer to Regional Products and Services for details of Amazon API Gateway service availability by region.
What can I manage through the Amazon API Gateway console?
General
Amazon API Gateway | Mobile Services
Through the Amazon API Gateway console, you can define the REST API and its associated resources and methods, manage the API lifecycle, generate client SDKs and view API metrics. You can also use the API Gateway console to define your APIs’ usage plans, manage developers’ API keys, and configure throttling and quota limits. All of the same actions are available through the API Gateway APIs.
What is a REST API?
General
Amazon API Gateway | Mobile Services
In Amazon API Gateway, a REST API is a group of resources and methods, or endpoints. REST APIs can be deployed to different stages and cloned to new versions.
What is a resource?
General
Amazon API Gateway | Mobile Services
A resource is a typed object that is part of your API’s domain. Each resource may have associated a data model, relationships to other resources, and can respond to different methods.You can also define resources as variables to intercept requests to multiple child resources.
What is a method?
General
Amazon API Gateway | Mobile Services
Each resource within a REST API can support one or more of the standard HTTP methods. You define which verbs should be supported for each resource (GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS) and their implementation. For example, a GET to the cars resource should return a list of cars. To connect all methods within a resource to a single backend endpoint, API Gateway also supports a special “ANY” method.
What is an usage plan?
General
Amazon API Gateway | Mobile Services
Usage plans help you declare plans for third-party developers that restrict access only to certain APIs, define throttling and request quota limits, and associate them with API keys. You can also extract utilization data on an per-API key basis to analyze API usage and generate billing documents. For example, you can create a basic, professional, and enterprise plans – you can configure the basic usage plan to only allow 1,000 requests per day and a maximum of 5 requests per second (RPS).
What is the Amazon API Gateway API lifecycle?
General
Amazon API Gateway | Mobile Services
With Amazon API Gateway, each REST API can have multiple stages. Stages are meant to help with the development lifecycle of an API – for example, after you’ve built your APIs and you deploy them to a development stage, or when you are ready for production, you can deploy them to a production stage.
What is a stage?
General
Amazon API Gateway | Mobile Services
In Amazon API Gateway, stages are similar to tags. They define the path through which the deployment is accessible. For example, you can define a development stage and deploy your cars API to it. The resource will be accessible at https://www.myapi.com/dev/cars. You can also set up custom domain names to point directly to a stage, so that you don’t have to use the additional path parameter. For example, if you pointed myapi.com directly to the development stage, you could access your cars resource at https://www.myapi.com/cars. Stages can be configured using variables that can be accessed from your API configuration or mapping templates.
What are stage variables?
General
Amazon API Gateway | Mobile Services
Stage variables let you define key/value pairs of configuration values associated with a stage. These values, similarly to environment variables, can be used in your API configuration. For example, you could define the HTTP endpoint for your method integration as a stage variable, and use the variable in your API configuration instead of hardcoding the endpoint – this allows you to use a different endpoint for each stage (e.g. dev, beta, prod) with the same API configuration. Stage variables are also accessible in the mapping templates and can be used to pass configuration parameters to your Lambda or HTTP backend.
What if I mistakenly deployed to a stage?
General
Amazon API Gateway | Mobile Services
Amazon API Gateway saves the history of your deployments. At any point, using the Amazon API Gateway APIs or the console, you can roll back a stage to a previous deployment.
Can I run multiple versions of the same REST API?
General
Amazon API Gateway | Mobile Services
Yes. Amazon API Gateway gives you the ability to clone an existing API. When you are ready to start working on the next major version of your API, you will be able to keep working on your version 1 and version 2 APIs simultaneously.
