About

This is a Stepwise "Tech Tuesday" demo app showing how to build a Slackbot with Google Cloud Function.

Bootstrap project (copied from Google Cloud Functions with Typescript)

1. Use gts to configure Typescript.

   npx gts init

2. Install the required packages:

   npm install @google-cloud/functions-framework
   npm install @types/express concurrently nodemon --save-dev

3. Add a start script to package.json, passing in the --source flag to point to the compiled code directory (configured by gts in this example). Also add a watch script to use for development:

     "scripts": {
       "start": "functions-framework --source=build/src/ --target=helloWorld",
       "watch": "concurrently \"tsc -w\" \"nodemon --watch ./build/ --exec npm run start\"",
       ...
     }
   

4. Replace the contents of src/index.ts with:

   import type { HttpFunction } from '@google-cloud/functions-framework/build/src/functions';
   
   export const helloWorld: HttpFunction = (req, res) => {
     res.send('Hello, World');
   };

5. Start the built-in local development server in watch mode:

   npm run watch

   This will continuously watch changes to your TypeScript project and recompile when changes are detected:

   [12:34:56 AM] Starting compilation in watch mode...
   [12:34:57 AM] Found 0 errors. Watching for file changes.
   ...
   Serving function...
   Function: helloWorld
   URL: http://localhost:8080/

Create Slack app

(No coding yet)

1. Open https://api.slack.com/ and Create an app

2. Select "From Scratch" and Fill App Name and workspace

3. Select Slash commands and Create New Command

4. Fill Create New Command form with:
   Command: /stepwise
   Request Url: https://not-valid.yet (we will get url later on and update it)
   Short Description: Tech tuesday demo bot

5. Install the app to your workspace

Start Development

1. Fill index.ts with following code:

import type {HttpFunction} from '@google-cloud/functions-framework/build/src/functions';


export const handleRequest: HttpFunction = (req, res) => {
   const command = req.body.text
   res.send(`Command: '${command}'`);
};

2. Run function locally with:

npm run watch

3. Run ngrok to create tunnel to your local machine:

ngrok http 8080

4. Copy https link from output of ngrok and use it as Slackbot command request url (See Create Slack app section)

5. Try running /stepwise test in your Slack. You should get following in response:

Command: test

Having such setup you can debug app locally.

Deploy it to Google Cloud Function

1. Create project
   gcloud projects create tech-tuesday-cloud-functions --folder=252221710142 --name="Tech Tuesday Cloud Functions" --set-as-default

2. Enable billing
   gcloud alpha billing projects link tech-tuesday-cloud-functions2 --billing-account=<yourBillingAccount>

3. Enable Cloud Build
   gcloud services enable cloudbuild.googleapis.com

4. Deploy Function
   gcloud functions deploy stepwiseBot --runtime nodejs16 --trigger-http --allow-unauthenticated --region=europe-central2

5. Copy https link from output of ngrok and use it as Slackbot command request url (See Create Slack app section) [link text itself]

6. Cleanup :)
   gcloud projects delete tech-tuesday