About

A simple Slack slash command integration that replies to various messages. It accepts POST requests in the slash command format, verifies the key & domain, and looks for handlers corresponding to the text field, dispatching as appropriate. Otherwise, it throws an error.

Uses async-await and the handy micro framework to provide a minimal interface. Ideal for deploying to now.sh.

Originally designed for Trondheim & Røros, it is easy to extend and customise to your liking. There is no routing to speak of, apart from handling each message.text differently for each command.

Development

• You should have node installed; the 6.9 LTS is known to work well
• Install dependencies with yarn or npm install
• Then yarn run start or npm start, and navigate to localhost:3000
• Send POST requests to the root; see the format below
• Add new handlers in modules or index.js, and link them to the switch in index.js. The demo handlers should give you an idea of what to return.

Deployment

The service is currently deployed using now.sh, which means you just run now at the project root.

Otherwise, the steps would be roughly:

• Install node
• Copy your code to the production server
• Set NODE_ENV=production
• Proxy Port 80 to the server port
• You might want to look into a process manager, or run the server as a service

Slack setup

• Go to your team's Add integrations option
• Select Slash Commands
• Customise Command; users will type /mycommandname message
• Add the URL of your public-facing service
• Set method to POST
• Add the token that you get either directly to index.js or the env variable SLACK_TOKEN
• Customise anything else to your liking

Usage / Slash Command Format

Slack describes it as:

token=xMbiJZV2dFxNSSWvINE5SY9Z
team_id=T0001
team_domain=example
channel_id=C2147483705
channel_name=test
user_id=U2147483697
user_name=Steve
command=/weather
text=94070
response_url=https://hooks.slack.com/commands/1234/5678

Of these, text is important to disambiguate which handler to use, and token to gate access. The other fields are also available under const message; you can combine them however you wish, and pass it on to the handlers.

Response_url is a bit more interesting; read the Slack documentation to learn more about it.

References

Slack slash-command docs: https://api.slack.com/slash-commands

Zeit micro: https://github.com/zeit/micro