Lambda to export twilio recordings to S3

index.js

'use strict';
const axios = require('axios');
const AWS = require('aws-sdk');
const S3UploadStream = require('s3-upload-stream');
const Twilio = require('twilio');

const ACCOUNT_SID = "AC2xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
const AUTH_TOKEN = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
const S3_BUCKET = "BUCKET-NAME";
const S3_PREFIX = "Recordings";

function add_leading_zero(number) {
    let n = number.toString();
    if (n.length < 2) { n = '0' + n; }
    return n;
}

function get_download_url(recording) {
    const apiVersion = recording.apiVersion;
    const recordingSID = recording.sid;
    return `https://api.twilio.com/${apiVersion}/Accounts/${ACCOUNT_SID}/Recordings/${recordingSID}.mp3`
}

function get_upload_path(recording, from_number, to_number) {
    const recordingDate = new Date(recording.dateCreated);
    const year = recordingDate.getFullYear();
    const month = add_leading_zero(recordingDate.getMonth() + 1);
    const day = add_leading_zero(recordingDate.getDate());
    const hour = add_leading_zero(recordingDate.getHours());
    const minute = add_leading_zero(recordingDate.getMinutes());
    const second = add_leading_zero(recordingDate.getSeconds());
    const duration = add_leading_zero(recording.duration);
    return `${S3_PREFIX}/${year}/${month}/${year}.${month}.${day}-${hour}.${minute}.${second}_${from_number}_${to_number}_${duration}s.mp3`
}

async function transfer_recording(download_url, upload_stream) {
    const response = await axios({method: 'GET', url: download_url, responseType: 'stream'});
    response.data.pipe(upload_stream);
    return new Promise((resolve, reject) => {
        upload_stream.on('uploaded', resolve)
        upload_stream.on('error', reject)
    });
}

module.exports.handler = async function(event, context, callback) {
    const client = Twilio(ACCOUNT_SID, AUTH_TOKEN);

    // Retrieving and deleting all recordings
    const recordings = await client.recordings.list();
    for (const recording of recordings) {
        if (recording.status !== "completed") { continue; }

        // Getting the upload and download paths
        const call = await client.calls(recording.callSid).fetch();
        const download_url = get_download_url(recording);
        const upload_path = get_upload_path(recording, call.from, call.to);
        let s3Stream = S3UploadStream(new AWS.S3());

        // Alternatively, one could download a ".wav" by using ".wav" in the in the download_url and a ContentType of "audio/x-wav"
        let upload_stream = s3Stream.upload({Bucket: S3_BUCKET, Key: upload_path, ContentType: 'audio/mpeg'});

        // Transferring to S3
        console.log(`Transferring ${recording.callSid} to ${upload_path}`);
        await transfer_recording(download_url, upload_stream);

        // Deleting recording
        await client.recordings(recording.sid).remove();
    }
    callback();
};

I deployed this code to my local and throw this error. Do you know why?

Yes. It is a credentials issue. You need to load an access key and secret key in your local environment variables so the script can upload to s3.

sorry, I don't know how to pass it. how to make aws upload request carry accesskey and secret key?

You need to login to the console, create a user, assign him a policy that allows uploading to s3 and then you will get the access key and secret key.

then set it with something like

export AWS_ACCESS_KEY_ID=AKIAIOSFODNN7EXAMPLE
export AWS_SECRET_ACCESS_KEY=wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
export AWS_DEFAULT_REGION=us-west-2

Now the recording can be upload to S3, but it's throw this warning, do you know why? and sometimes it's will run a long time(more than 1h) in here:"let upload_stream = s3Stream.upload({Bucket: S3_BUCKET, Key: upload_path, ContentType: 'audio/mpeg'});"
FYI, I pass credentialData like this:
let credentialsData={ accessKeyId: 'AKIASXXXXXXUXHFPU', secretAccessKey: 'TAuXXXXXXXXXXXXXLe4mN8jOfrUemvIJfb7fe6swK' };
let s3Stream = S3UploadStream(new AWS.S3(credentialsData));

When It's very slow on code:"let upload_stream = s3Stream.upload({Bucket: S3_BUCKET, Key: upload_path, ContentType: 'audio/mpeg'});"
it's throw warning like this.