Overview

A module for AWS API gateway client based on auto-generated JavaScript SDK. This module can be used not only for Node.js but for front-end. In addition, it generalizes original SDK's endpoint specific methods.

Reference:
https://docs.aws.amazon.com/apigateway/latest/developerguide/how-to-generate-sdk.html

Prerequisites

For the JavaScript SDK to work your APIs need to support CORS. The Amazon API Gateway developer guide explains how to setup CORS for an endpoint.

Install

``
npm install aws-api-gateway-client
`

Use the SDK in your project

Require module
`
var apigClientFactory = require('aws-api-gateway-client').default;
`

Set invokeUrl to config and create a client. For authorization, additional information is required as explained below.
`
config = {invokeUrl:'https://xxxxx.execute-api.us-east-1.amazonaws.com'}
var apigClient = apigClientFactory.newClient(config);
`

Calls to an API take the form outlined below. Each API call returns a promise, that invokes either a success and failure callback

`
var pathParams = {
//This is where path request params go.
userId: '1234',
};
// Template syntax follows url-template https://www.npmjs.com/package/url-template
var pathTemplate = '/users/{userID}/profile'
var method = 'GET';
var additionalParams = {
//If there are query parameters or headers that need to be sent with the request you can add them here
headers: {
param0: '',
param1: ''
},
queryParams: {
param0: '',
param1: ''
}
};
var body = {
//This is where you define the body of the request
};

apigClient.invokeApi(pathParams, pathTemplate, method, additionalParams, body)
.then(function(result){
//This is where you would put a success callback
}).catch( function(result){
//This is where you would put an error callback
});
`

Using AWS IAM for authorization

To initialize the SDK with AWS Credentials use the code below. Note, if you use credentials all requests to the API will be signed. This means you will have to set the appropriate CORS accept-* headers for each request.

`
var apigClient = apigClientFactory.newClient({
invokeUrl:'https://xxxxx.execute-api.us-east-1.amazonaws.com', // REQUIRED

region: 'eu-west-1', // REQUIRED: The region where the API is deployed.

accessKey: 'ACCESS_KEY', // REQUIRED

secretKey: 'SECRET_KEY', // REQUIRED

sessionToken: 'SESSION_TOKEN', // OPTIONAL: If you are using temporary credentials
you must include the session token.

systemClockOffset: 0, // OPTIONAL: An offset value in milliseconds to apply to signing time

retries: 4, // OPTIONAL: Number of times to retry before failing. Uses axios-retry plugin.

retryCondition: (err) => { // OPTIONAL: Callback to further control if request should be retried.
return err.response && err.response.status === 500; // Uses axios-retry plugin.
},

retryDelay: 100 || 'exponential' || (retryCount, error) => { // OPTIONAL: Define delay (in ms) as a number, a callback, or
return retryCount * 100 // 'exponential' to use the in-built exponential backoff
}, // function. Uses axios-retry plugin. Default is no delay.

shouldResetTimeout: false // OPTIONAL: Defines if the timeout should be reset between retries. Unless
// shouldResetTimeout is set to true, the request timeout is
// interpreted as a global value, so it is not used for each retry,
// but for the whole request lifecycle.
});
`

Using API Keys

To use an API Key with the client SDK you can pass the key as a parameter to the Factory object. Note, if you use an apiKey it will be attached as the header 'x-api-key' to all requests to the API will be signed. This means you will have to set the appropriate CORS accept-* headers for each request.

`
var apigClient = apigClientFactory.newClient({
invokeUrl:'https://xxxxx.execute-api.us-east-1.amazonaws.com', // REQUIRED
apiKey: 'API_KEY', // REQUIRED
region: 'eu-west-1' // REQUIRED
});
``