Download the media files with node in Azure serverless

Pre-requisite for Node in Azure Serverless 

1. You have created a function with with name "download-files"
2. You have downloaded ffmpeg files (ffmpeg.exe) in "site -> wwwroot-> bin"
3. You have created a folder with name wav_to_mp3 "site -> wwwroot-> wav_to_mp3"

Source Code

//Download the Required module
const http = require('https');
const fs = require('fs');
//const childProcess = require('child_process');
const path = require('path');

//Define constants
const VIDEO_PATH = 'wav_to_mp3/';
const ffmpegLib='bin/ffmpeg';

module.exports =  function (context, req) {
    ////////////// params declaration
    let bodyData=req.body;
    let tourStreamName=bodyData.tour_stream_name;
    let videoUrls=bodyData.url;
    
    let filename='';
    let filenameSuccessLog={};
    let completedCounter=0;
    if (tourStreamName && videoUrls.length>0) {
        ////////////////////// ALL VIDEOS DOWNLOAD ////////////////////////////
        //const forLoop = async _ => {
         videoUrls.forEach(async (url) => {
              filename=path.basename(url); 
             // let videoDownload=VIDEO_PATH+filename;
                //full video url, filename, force download
                downloadFileAsync(url,filename,0).then(data=>{  
                   filenameSuccessLog[data.filename]=data.success;
                   completedCounter++;
                   if(videoUrls.length==completedCounter){
                       messageData(200,{success:1,'msg':'',result:filenameSuccessLog});
                   }                    
               }); 
          })
        //}    
         //forLoop();
        ////////////////////// ALL VIDEOS DOWNLOAD ////////////////////////////

    } else {
        messageData(200,{success:0,msg:"Parameter missing (tour_stream_name OR url)",'result':{}});
    }
    
    
    
    //for print the message
    function messageData(statusCode,message){
        context.res = {
            status: statusCode,
            body: message,
            headers: {
                'Content-Type': 'application/json'
            }
        };   
         context.done();
               
    } 
    
};



///////////////////////////// Other Functions ////////////////////////////////////
/**
 * @url: url of video
 * @destination: file with name download in wav_to_mp3
 * @forcedownload: 1 means download again even
 */
async function downloadFileAsync(url, destination,forcedownload) {
    return new Promise(function(resolve, reject) {
        let result={success:0,'msg':'',filename:destination};
        if (fs.existsSync(VIDEO_PATH+destination) && forcedownload==0) {
            result.success=1
            resolve(result);            
        }else{
            const file = fs.createWriteStream(VIDEO_PATH+destination);
            const request = http.get(url, (res) => {
              res.pipe(file);
            });
            request.once('error', (error) => 
              {
                  result.msg=error;
                  reject(result);
              }
            );
            file.once('finish', () => 
              {
                result.success=1
                resolve(result);
              }
            );             
        }
       
        
    })
}

///////////////////////////// Other Functions ////////////////////////////////////

URL: https://function-name.azurewebsites.net/api/download-files
Method: POST
Request:

{"tour_stream_name":"arun","url":["https://example.com/video/0_20190821064650782.mp4","https://example.com/video/tq_33038dev-GM-ma9kW-1106-26079.mp4"]}

Response:

{
    "success": 1,
    "msg": "",
    "result": {
        "tq_33038dev-GM-ma9kW-1106-26079.mp4": 1,
        "0_20190821064650782.mp4": 1
    }
}