REST API with a Cloudflare Worker and a MongoDB Atlas Cluster

This project explains how to build a REST API in a Cloudflare worker using MongoDB Realm Web SDK and a MongoDB Atlas cluster to store the data.

How it Works

• The MongoDB Atlas cluster stores the data in the cloudflare.todos collection.
• A MongoDB Realm App manages the authentication and the collection access rules.
• A Cloudflare worker uses the Realm Web SDK to authenticate and retrieve the data that is then exposed with a REST API.

Prerequisites

• MongoDB Cloud account.
• MongoDB Atlas Cluster (M0 is fine).
• MongoDB Realm Application created & deployed.
  • with Authentication API Keys turned on + an API key created.
  • with a rule on the collection cloudflare.todos with a role "owner" with read and write access on all the fields, applied when {"owner": "%%user.id"}.
• Cloudflare account (free plan is fine) with a *.workers.dev subdomain.

To deploy & test the API we need:

• The Realm Application ID (top left corner).
• The Realm authentication API key (in Authentication tab > API Keys).
• The Cloudflare account login/password.
• The Cloudflare account ID (in Workers tab > Overview).
• The Cloudflare *.workers.dev subdomain (in Workers tab > Overview).

Build and Deploy

Clone this repository

git clone git@github.com:mongodb-developer/cloudflare-worker-rest-api-realm-atlas.git
cd cloudflare-worker-rest-api-realm-atlas

Edit the file wrangler.toml

• replace CLOUDFLARE_ACCOUNT_ID by your real Cloudflare account ID.
• replace MONGODB_REALM_APPID by your real MongoDB Realm App ID.

If you want to use the bash files to test the REST API, edit the file api_tests/variables.sh:

• replace YOUR_SUBDOMAIN so the final worker URL matches yours.
• replace YOUR_REALM_AUTH_API_KEY with your Realm auth API key.

Run the following commands:

$ npm i @cloudflare/wrangler -g
$ wrangler login
$ wrangler publish
$ cd api_tests
$ ./post.sh "Write a good README.md for Github"
$ ./post.sh "Commit and push"
$ ./findAll.sh
$ ./findOne.sh <OBJECT_ID> # replace with an _id from the previous command
$ ./patch.sh <OBJECT_ID> true
$ ./findAll.sh # note that done=true now on your todo
$ ./deleteOne.sh <OBJECT_ID>
$ ./findAll.sh # only one left

You can also navigate to your MongoDB Atlas Cluster and browse your collection cloudflare.todos to confirm the above tests.

Authors

• Luke Edwards ledwards@cloudflare.com
• Maxime Beugnet maxime@mongodb.com