AWS - API Gateway with Lambda

 Step 1: Create a NodeJs Lambda function

•         Select Lambda service and Click on Create function button
•         Select Author From Scracth.
•         Function name : ApiFunc
•         Runtime: Node.js 14.x
•         Permission ---> change default execution role
•         select create new role from AWS policy Template
•         and provide the role name apifuncrole

 Click on Create function button

Step 2: Use the below code for the Lambda function 

'use strict';

const https = require('https');

exports.handler = async (event) => {

    let dataString = '';

    const response = await new Promise((resolve, reject) => {

        const req = https.get("https://jsonplaceholder.typicode.com/todos/1", function(res) {

          res.on('data', chunk => {

            dataString += chunk;

          });

          res.on('end', () => {

            resolve({

                statusCode: 200,

                body: JSON.stringify(

                        {

                            "data": JSON.parse(dataString).title,

                            "timestamp": new Date()

                        }, null, 4

                    )

            });

          });

        });

       

        req.on('error', (e) => {

          reject({

              statusCode: 500,

              body: 'Something went wrong!'

          });

        });

    });

   

    return response;

};

Then Click on  File--->save and Click on Deploy

Step 3: Create Rest API using API Gateway.

•       Select API Gateway Service
•       Click on Create API button
•       Select RestAPI and click on Build button
•       Select New API
•       Api Name: myapi

  Click on Create Api Button.

Step 4: Create a Resource

•           Select Action--> Create Resource
•           Resource Name: what-is-my-title

     Click on Create Resource Button

Step 5: Select resource what-is-my-title and Goto Action---> Create Method from Drop down select Get Method and click on tick mark. 

Step 6: Click on Get Method 

•            Integration Type: Lambda Function
•           Select check box Use Lambda proxy Integration
•           Lambda function: <<Lamda function name>> 

Click on Save button

Step 7: Select GET and Goto Action--->Deploy API

            Deployment Stage : New Stage

            Stage Name: api

Click on the Deploy button.

Step 8: You will find one Invoke URL on the top and open that URL in a new tab and at the end of the URL add what-is-my-title

  You will be able to see the title and current date and time

Step 9: Click on Export tab and select the Swagger and select Export as Swagger and click on json. It will download the json file for api Gateway.

Step 9: Take screen shot and copy IAM Role policy