howdoi-bot

Ever have an existential question that you need to know the answer to? Howdoi-bot is a serverless Discord bot that queries Yahoo Answers and gives you the best result. Included is the howdoi-bot code, and configuration for packaging/deploying the service via Cloudformation.

Requirements

• AWS SAM CLI
• Docker desktop
• An AWS account

Codebase

• template.yml: defines the project, including a gateway, 2 lambda functions, log groups, and IAM roles.
• bin/register_command.sh: For registering your slash command with Discord the first time you set up the project.
• bin/setup.sh:
  • Creates the /build directory
  • Installs dependencies in Amazon Linux using Docker, and creates a .zip of the dependencies
  • Takes all the code in /src and creates a second .zip
• src/input.py: Contains the lambda handler that Discord talks to.
• src/response.py: Contains the lambda handler that actually fetches your response (as this can take longer than Discord allows slash commands to take).

First Time Setup

1. Create a new Discord application and bot on the Discord developer portal. Note the bot's public key and bot token.

2. Install and zip python package requirements with bash bin/setup.sh.

3. Create a bucket in S3 to store your assets.

4. Run the following to package your template:

   sam package \
       --s3-bucket <YOUR_S3_BUCKET_HERE> \
       --template-file template.yml \
       --output-template-file output.yml

5. Run the following command to deploy your stack via Cloudformation:

   sam deploy \
       --template-file output.yml \
       --stack-name howdoi-bot \
       --capabilities CAPABILITY_IAM \
       --parameter-overrides \
           DiscordPublicKey=<YOUR_PUBLIC_KEY_HERE> \

6. Once your stack has been created, check your API. Copy the Invoke URL.

7. On your Discord application page, paste the invoke URL in the Interractions Endpoint URL box, and press 'Save'.

8. Register your slash command. You can run the curl command in bin/register_command.sh after adding your application ID/bot token (see further reading for more info).

9. Invite your discord bot to your room. Enjoy the shitposts!

Pushing Out Changes

Whenever you update the code, you can do steps 2, 4, and 5 to update your Cloudformation stack. In step 4, You may need to pass in the --force-upload flag for your assets to replace the old ones in S3.

Further Reading

• https://oozio.medium.com/serverless-discord-bot-55f95f26f743 - Medium article detailing a manual setup similar to this one
• https://discord.com/developers/docs/interactions/slash-commands#registering-a-command - Discord API: Registering a slash command