Cloudflare worker example app

awwbot is an example app that brings the cuteness of r/aww straight to your Discord server, hosted on Cloudflare workers. Cloudflare Workers are a convenient way to host Discord bots due to the free tier, simple development model, and automatically managed environment (no VMs!).

The tutorial for building awwbot is in the developer documentation

Resources used

• Discord Interactions API
• Cloudflare Workers for hosting
• Reddit API to send messages back to the user

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Project structure

Below is a basic overview of the project structure:

├── .github/workflows/ci.yaml -> Github Action configuration
├── src
│   ├── commands.js           -> JSON payloads for commands
│   ├── reddit.js             -> Interactions with the Reddit API
│   ├── register.js           -> Sets up commands with the Discord API
│   ├── server.js             -> Discord app logic and routing
├── test
|   ├── test.js               -> Tests for app
├── wrangler.toml             -> Configuration for Cloudflare workers
├── package.json
├── README.md
├── .eslintrc.json
├── .prettierignore
├── .prettierrc.json
└── .gitignore

Configuring project

Before starting, you'll need a Discord app with the following permissions:

• bot with the Send Messages and Use Slash Command permissions
• applications.commands scope

⚙️ Permissions can be configured by clicking on the OAuth2 tab and using the URL Generator. After a URL is generated, you can install the app by pasting that URL into your browser and following the installation flow.

Creating your Cloudflare worker

Next, you'll need to create a Cloudflare Worker.

• Visit the Cloudflare dashboard
• Click on the Workers tab, and create a new service using the same name as your Discord bot

Running locally

First clone the project:

git clone https://github.com/discord/cloudflare-sample-app.git

Then navigate to its directory and install dependencies:

cd cloudflare-sample-app
npm install

⚙️ The dependencies in this project require at least v18 of Node.js

Local configuration

💡 More information about generating and fetching credentials can be found in the tutorial

Rename example.dev.vars to .dev.vars, and make sure to set each variable.

.dev.vars contains sensitive data so make sure it does not get checked into git.

Register commands

The following command only needs to be run once:

$ npm run register

Run app

Now you should be ready to start your server:

$ npm start

Setting up ngrok

When a user types a slash command, Discord will send an HTTP request to a given endpoint. During local development this can be a little challenging, so we're going to use a tool called ngrok to create an HTTP tunnel.

$ npm run ngrok

This is going to bounce requests off of an external endpoint, and forward them to your machine. Copy the HTTPS link provided by the tool. It should look something like https://8098-24-22-245-250.ngrok.io. Now head back to the Discord Developer Dashboard, and update the "Interactions Endpoint URL" for your bot:

This is the process we'll use for local testing and development. When you've published your bot to Cloudflare, you will want to update this field to use your Cloudflare Worker URL.

Deploying app

This repository is set up to automatically deploy to Cloudflare Workers when new changes land on the main branch. To deploy manually, run npm run publish, which uses the wrangler publish command under the hood. Publishing via a GitHub Action requires obtaining an API Token and your Account ID from Cloudflare. These are stored as secrets in the GitHub repository, making them available to GitHub Actions. The following configuration in .github/workflows/ci.yaml demonstrates how to tie it all together:

release:
  if: github.ref == 'refs/heads/main'
  runs-on: ubuntu-latest
  needs: [test, lint]
  steps:
    - uses: actions/checkout@v3
    - uses: actions/setup-node@v3
      with:
        node-version: 18
    - run: npm install
    - run: npm run publish
      env:
        CF_API_TOKEN: ${{ secrets.CF_API_TOKEN }}
        CF_ACCOUNT_ID: ${{ secrets.CF_ACCOUNT_ID }}

Storing secrets

The credentials in .dev.vars are only applied locally. The production service needs access to credentials from your app:

$ wrangler secret put DISCORD_TOKEN
$ wrangler secret put DISCORD_PUBLIC_KEY
$ wrangler secret put DISCORD_APPLICATION_ID

Questions?

Feel free to post an issue here, or reach out to @justinbeckwith!