lambda-discord-webhook

Simple template for setting up a scheduled lambda function that triggers a discord webhook to send a message.

Meant to be a starting point for someone to set up their own webhook triggered on a schedule.

Summary

Use this repository as a starting place to automate discord messages. This package will help you set up the necessary AWS Infratructure to have a lambda triggered on a schedule that will call your code.

Prerequisites

1. Install the AWS CDK Toolkit
   • You will also need Docker installed and running locally
   • Make sure to follow the instructions to get credentials set up
2. Have your choice of npm/yarn installed

Getting started

1. Create a webhook to call in Discord by following these instructions.
2. Fork this repository and pull locally
   • To change the schedule edit the cronRule in bin/src.ts
   • To modify the discord message edit the handler method in src/lambdaHandler.ts
3. Create a .env file (using .env.example as an example). Use the URL from the webhook's "Copy Webhook URL" button on discord for DISCORD_WEBHOOK_URL.
4. Run npm run build to ensure everything works
5. Run npm run test-local to ensure the webhook is sending messages to the discord channel
   • Use this whenever you want to test your lambda code without deploying. Make sure to build first
6. Run cdk deploy to deploy!
   • You'll want to re-run this any time you want to deploy new code to the lambda, or you set a new schedule
   • If you encounter a timeout issue, try modifying the timeout in lib/typescript-lambda-stack.ts

Architecture

This package utilizies AWS CDK, a tool which is used to set up AWS Infrastucture using code.

1. Set up an AWS Lambda defined in TypeScript.
2. Set up an AWS EventBridge rule that is triggered on a schedule. The schedule is defined in cron but other schedules can be used as well. The target of this rule is the Lambda function.

CDK commands

• npm run build compile typescript to js
• npm run watch watch for changes and compile
• npm run test perform the jest unit tests
• cdk deploy deploy this stack to your default AWS account/region
• cdk diff compare deployed stack with current state
• cdk synth emits the synthesized CloudFormation template