cf-mongodb-polyfills

This package allows the use of the mongodb npm package in a cloudflare worker. It does this by polyfilling the net and tls modules in the mongodb package to use the cf-mongodb-polyfills package instead.

Description

Currently cloudflare's workerd does not support using mongodb package to connect to mongodb. This is due to the fact that net.createConnection and tls.connect arent implemented in the worker runtime (ref) even with the nodejs_compat or nodejs_compat_v2 compatiblity flags enabled.

However, via the use of the module aliasing feature in wrangler.toml, we can replace the net and tls modules in the mongodb package with polyfills in this package. This package provides polyfills for the net and tls modules which will use cloudflare:sockets npm package to create a tcp connection to the mongodb server.

Installation

To install the package, run:

npm install cf-mongodb-polyfills

Modify wrangler.toml

To use the package in a cloudflare worker app, you must create module aliases in the wrangler.toml to point to the polyfills that are in this package.

# wrangler.toml
# ...

[alias]
"net" = "@jchoi2x/cf-mongodb-polyfills/net"
"dns" = "@jchoi2x/cf-mongodb-polyfills/dns"
"tls" = "@jchoi2x/cf-mongodb-polyfills/tls"

Usage

With these changes in place, you can now use the mongodb package in your cloudflare worker app.

import { MongoClient } from 'mongodb';

export default {
  async fetch(request, env, ctx): Promise<Response> {

    // connect to atlas mongodb
    const tlsClient = new MongoClient('mongodb+srv://sharedddas:[email protected]/?retryWrites=true&w=majority&appName=dev');
    await tlsClient.connect();

    // connect to mongo running locally
    const client = new MongoClient('mongodb://localhost:27017');
    await client.connect();

    const db = tlsClient.db('test');
    const users = await db.collection('users').find({}).toArray().limit(10);

    return Response.json({
      users
    })
  },
} satisfies ExportedHandler<Env>;

Contributing

Contributions are welcome! Please open an issue or submit a pull request.