Running node-maxmind in browser

README.md

node-maxmind in browser

Spoiler: it's possible.

An experiment of trying to run node-maxmind Node.js library in a browser.

See https://ilin.dk/weblog/maxmind-in-browser for more details about the files below.

See the live version running on https://nilfalse.com/labs/geoip/

index.js

import { Buffer } from 'buffer';

import * as maxmind from 'maxmind';

export async function load() {
  const response = await fetch('./data/GeoLite2-Country.mmdb');

  const buf = Buffer.from(await response.arrayBuffer());
  buf.utf8Slice = function (start, end) {
    return this.toString('utf8', start, end);
  };

  return new maxmind.Reader(buf);
}

webpack.config.js

const path = require('path');

module.exports = {
  node: {
    net: 'empty',
  },

  module: {
    rules: [
      {
        test: path.resolve(__dirname, './node_modules/maxmind/lib/fs.js'),
        use: 'null-loader',
      },
    ],
  },
};