Fn Slack Bot

Fn functions to implement a simple Slack Bot

step 0

• git clone https://github.com/abhirockzz/fn-slack-bot-sample
• make sure you have Fn installed on an infra which can be accessed from public internet (e.g. VM), or use ngrok on your local machine

Handle slack verification challenge function

Start Fn server - fn start

From a different terminal, configure Docker

• docker login (use your docker registry credentials)
• export FN_REGISTRY=<docker repository>

deploy the function to respond to slack verification challenge

• cd slack-verification-challenge-handler
• fn -v deploy --app fnbot

the public URL for the function should be http://your_ip:port/r/fnbot/service (fnbot is the app name which service is the path)

Slack config

Sign into your Slack workspace - if you don't have one, please create it

Before you start, you'll need a Slack App - click here to get started

To use your Slack App as a bot, first you'll need to create a Bot User for it - refer to section 1. Creating a bot user on this page

Setup the Events API for your bot. Refer to section 2. Setting up the Events API on this page

• In the Request URL, enter your function endpoint (as mentioned above)

• Subscribe to the app_mention Bot Event (the Fn bot function is designed to handle this event)

For the next steps, refer section 3. Installing the bot to a workspace on this page

• Install the bot to your workspace

• Store the Bot User OAuth Access Token for later use

• from the Basic Information section in your app settings page, scroll down and make a note of the verification token

Deploy the bot function

• cd slack-app-mention-event-handler
• update the SLACK_VERIFICATION_TOKEN and SLACK_BOT_OAUTH_TOKEN in the config section in func.yaml with the values you saved in the previous step
• deploy the function - fn -v deploy --app fnbot. Note that this will override the challenge verification function because
  • challenge verification is a one-time process and
  • once you configure the request URL, Slack will send all your subscribed events to the same endpoint/URL i.e. you cannot change it

Have fun with Fn Bot !

The bot itself is super simple (a.k.a dumb). It responds to your mention by returning a message with the current date - not ground breaking, but it works!

Head over to your Slack workspace and simple mention your bot (by its name) e.g. @testbot

I told you, it's dumb.. no matter what you throw at it !

Fn Concepts

TODO details

• uses async function
• simple JSON to POJO data bindings