index.js

require('dotenv').config()
const express = require("express");
const AWS = require('aws-sdk');

const app = express();
const PORT = 3000;

app.get("/:bucket/(*/:key|:key)", (req, res) => {
    try{
        let {bucket, key} = req.params;

        let s3 = new AWS.S3({
            accessKeyId: process.env.S3_KEY,
            secretAccessKey: process.env.S3_SECRET,
            // endpoint: process.env.HOST ,
            // s3ForcePathStyle: true, // needed with minio?
            signatureVersion: 'v4'
        });
        s3.getObject({Bucket: bucket, Key: key, Range: "bytes=0-"}, function(err, data) {
            if (err) res.status(404).send(); // an error occurred
            else{
                if (data.ContentType.includes("gzip")){
                    res.set('Content-Encoding', 'gzip');
                }
                res.send(data.Body);
            }
        });
    }
    catch (e) {
        console.error(e);
        res.status(500).send();
    }

});

app.listen(PORT, () => {
    console.log("The server is running on port:", PORT);
});