A CDK Construct for creating a serverless Discord bot. All you need to do is supply your code to handle the commands!
This is the architecture for how this project is laid out server-side. The tools used to create these diagrams are:
The bot has a fairly straightforward setup:
The biggest confusion likely stems from the use of two Lambda functions instead of one. This is to ensure that the initial request can respond within Discord's 3 second time limit and return a proper response to the user.
The usage is split into two parts: The AWS CDK stack that will be used, and a "commands" script that actually handles responding. It's recommended that you are familiar with CDK first before diving into using this.
For handling commands, you just need to provide a Lambda function for sending response to Discord's Web APIs. As an example of how this can be done:
import {Context, Callback} from 'aws-lambda'; import { IDiscordEventRequest, IDiscordResponseData, getDiscordSecrets, sendFollowupMessage } from 'discord-bot-cdk-construct'; export async function handler(event: IDiscordEventRequest, context: Context, callback: Callback): Promise<string> { const discordSecret = await getDiscordSecrets(); const endpointInfo = { authToken: discordSecret?.authToken, applicationId: discordSecret?.applicationId }; const response = { tts: false, content: 'Hello world!', embeds: [], allowedMentions: [], }; if (event.jsonBody.token && await sendFollowupMessage(endpointInfo, event.jsonBody.token, response)) { console.log('Responded successfully!'); } else { console.log('Failed to send response!'); } return '200'; }To create a stack to make use of the above script, you can create a stack like so:
import {Duration, Stack} from 'aws-cdk-lib'; import {Runtime} from 'aws-cdk-lib/aws-lambda'; import {NodejsFunction} from 'aws-cdk-lib/aws-lambda-nodejs'; import {DiscordBotConstruct} from 'discord-bot-cdk-construct'; import {Construct} from 'constructs'; import * as path from 'path'; /** * Creates a sample Discord bot endpoint that can be used. */ export class SampleDiscordBotStack extends Stack { /** * The constructor for building the stack. * @param {Construct} scope The Construct scope to create the stack in. * @param {string} id The ID of the stack to use. */ constructor(scope: Construct, id: string) { super(scope, id); // Create the Commands Lambda. const discordCommandsLambda = new NodejsFunction(this, 'discord-commands-lambda', { runtime: Runtime.NODEJS_18_X, entry: path.join(__dirname, '../functions/DiscordCommands.ts'), handler: 'handler', timeout: Duration.seconds(60), }); const discordBot = new DiscordBotConstruct(this, 'discord-bot-endpoint', { commandsLambdaFunction: discordCommandsLambda, }); } }This can of course then be used in your CDK application like so:
import { App } from 'aws-cdk-lib'; import { SampleDiscordBotStack } from './stacks/sample-discord-bot-stack'; const app = new App(); const startAPIStack = new SampleDiscordBotStack(app, 'SampleDiscordBotStack');A full example project utilzing this construct can be found here. Specifically, the start-api-stack.ts file uses the construct, with DiscordCommands.ts being the commands file (like shown above).
In order to package everything with JSII, ensure you have the following installed:
- Python3
- Open JDK
- Maven
See JSII's Prerequisites Documentation for more information.
npm run buildcompile typescript to jsnpm run watchwatch for changes and compilenpm run testperform the jest unit testsnpm run lintperform a lint check across the codenpm run fix-lintfix any lint issues automatically where possiblenpm run packagepackage all of the bindings for distribution