Create a signed Cloudfront URL for an object in S3 on AWS

getImage.js

const AWS = require("aws-sdk");
var fs = require('fs');

exports.GetImage = async(event) => {

    try {
        let image = event['pathParameters']['img']
        let ImageKey = `${process.env.IMAGE_FOLDER}/${image}`;

        const cloudfrontAccessKeyId = process.env.CLOUDFRONT_KEY_ID;
        const cloudFrontPrivateKey = fs.readFileSync('cloudfront-pk.pem', 'utf8');
        const signer = new AWS.CloudFront.Signer(
            cloudfrontAccessKeyId,
            cloudFrontPrivateKey
        );

        const signedUrl = signer.getSignedUrl({
            url: `https://${process.env.CLOUDFRONT_DOMAIN_NAME}/${ImageKey}`,
            expires: Math.floor((Date.now() + process.env.URL_EXPIRE) / 1000),
        });

        let body = {
            signed_image_url: decodeURI(signedUrl)
        };

        return {
            statusCode: 200,
            body: JSON.stringify(body),
        };

    } catch (err) {
        console.log(err)
        return {
            statusCode: err.statusCode || 400,
            body: err.message || JSON.stringify(err.message),
        };
    }
};