app.js

import express from "express";
import request from "request";
import async from "async";
import archiver from "archiver";

const app = express();
const port = 3003;

app.get("/", async (req, res) => {
  console.time("zip");
  const urls = [
    "https://picsum.photos/800?random=1",
    "https://picsum.photos/800?random=2",
    "https://picsum.photos/800?random=3",
    "https://picsum.photos/800?random=4",
    "https://picsum.photos/800?random=5",
    "https://picsum.photos/800?random=6",
    "https://picsum.photos/800?random=7",
    "https://picsum.photos/800?random=8",
    "https://picsum.photos/800?random=9",
    "https://picsum.photos/800?random=10",
    "https://picsum.photos/800?random=11",
    "https://picsum.photos/800?random=12",
    "https://picsum.photos/800?random=13",
    "https://picsum.photos/800?random=14",
    "https://picsum.photos/800?random=15",
    "https://picsum.photos/800?random=16",
    "https://picsum.photos/800?random=17",
    "https://picsum.photos/800?random=18",
    "https://picsum.photos/800?random=19",
    "https://picsum.photos/800?random=20",
    "https://picsum.photos/800?random=21",
    "https://picsum.photos/800?random=22",
    "https://picsum.photos/800?random=23",
    "https://picsum.photos/800?random=24",
    "https://picsum.photos/800?random=25",
    "https://picsum.photos/800?random=26",
  ];
  res.attachment("example.zip");
  await zipMaterials(res, urls);
});

async function zipMaterials(res, urls) {
  const zipArchive = archiver("zip");
  zipArchive.pipe(res);

  async.eachLimit(
    urls,
    25,
    function (url, done) {
      var stream = request.get(url);

      stream
        .on("error", function (err) {
          return done(err);
        })
        .on("end", function () {
          return done();
        });

      zipArchive.append(stream, { name: `${url.replace(/^.*\//, "")}.png` });
    },
    function (err) {
      if (err) throw err;
      zipArchive.finalize();
      console.timeEnd("zip");
    }
  );
}

app.listen(port, () =>
  console.log(`Example app listening at http://localhost:${port}`)
);