Overview

This is an example project showing how to handle interactivity from slack. It uses Slack Block Kit to add a button to a message and Slack app interactivity to receive a webhook and post a message back to the user.

Setup

Local machine

You'll need to install ruby 2.6.5 and bundler on your machine. I use rbenv which isn't entirely terrible.

$ rbenv install 2.6.5
$ gem install bundler

Then, install the gems in Gemfile

$ bundle install

Finally, you're ready to start the test server

$ bundle exec ./server.rb

Change slack url

Modify server.rb and change the SLACK_URL to your applcation's webhook url.

Get a development URL

In this example I use localhost.run to expose my local development instance to the internet to that Slack can invoke my app under development. You may have to do some fancy footwork to install ssh if you're running on a windows box:

$ ssh -R 80:localhost:4567 ssh.localhost.run
Connect to http://xxxxx.localhost.run or https://xxxxx.localhost.run

Make note of your localhost.run https url, it'll change every time you start a new tunnel.

Setup slack webooks

Set the Request URL for your app (as described here) to the localhost.run https URL above with /slack-webhook appended. For example, if your localhost.run https URL is https://awesome-123.localhost.run you'll set RequestURL to https://awesome-123.localhost.run/slack-webhook.

Running the example

Finally, test it out:

$ curl -X POST -d '{"name": "Gregg"}' -H 'Content-Type: application/json' http://localhost:4567/hello