CanteenBot

Accessing the canteen menu for The News Building is hard. This repo contains a scraper and various service integrations to make life a little easier.

CanteenBot is built as a series of Serverless functions and hosted on AWS Lambda. Each function has at minimum a handler.js file, which is Serverless’ entry point.

Core

The core server accepts requests from service integrations in the format http://[coreURL]?message_type=TYPE&message_param=PARAM and returns data accordingly.

Valid message types are:

• MENU for requesting a given day’s menu
• INGREDIENT for requesting a list of days on which a given ingredient is being served

Menus

Valid message parameters for the MENU type are:

today | tomorrow | monday | tuesday | wednesday | thursday | friday | saturday | sunday

For example:

http://[coreURL]?message_type=MENU&message_param=monday

The response will be JSON in the following format:

{
  "data": {
    "url": "http://5438cpa251hgt.co.uk/canteen-thursday",
    "timestamp": "Thu Feb  2 11:00:01 2017",
    "day": "Thursday",
    "locations": [
      {
        "menu": "Malayasian market lamb kurma malaysian indian lamb curry with nasi biriyani and asian slaw add on: roti canai\n",
        "location": "Global Kitchen"
      },
      ...
    ]
  }
}

It contains the following fields:

• url: the relevant page of the canteen’s website
• timestamp: the timestamp at which the menu was scraped
• day: the day of the week the menu is for
• locations: an array of menu and location, which represent the different options available in the canteen that day

Ingredients

The message parameter for the INGREDIENT type must not be blank. If multiple words are passed, only the first will be considered.

For example:

http://[coreURL]?message_type=INGREDIENT&message_param=potato

The current version of CanteenBot does a simple string match, so for example burgers may return no results if the menu actually says burger.

The response will be JSON in the following format:

{
  "data": [
    "Tuesday"
  ]
}

The data field will be an array of all the days on which the given ingredient appears in a menu.

Errors

Error messages will be JSON in the following format:

{
  "error": "Both message_type and message_param must be provided."
}

Scraper

The scraper function scrapes the canteen’s website on a regular basis, converts the results to JSON and places the resulting files on S3.

Slack

The slack function powers a Slackbot that can be installed into any number of Slack teams.

The Slackbot can be installed for your team by clicking here.

During the installation process the function handles Slack's OAuth flow and then stores a record of the authenticated Slack team in DynamoDB. The function expects the canteenbot DyanmoDB table to already exist and to be accessible to the slack Lambda function.

Slash commands

The Slackbot listens for slash commands via POST. It will then query the core server for data accordingly, and return a message formatted for Slack.

All commands must begin with /canteen.

Valid menu commands are:

/canteen today | /canteen tomorrow | /canteen monday | /canteen tuesday | /canteen wednesday | /canteen thursday | /canteen friday | /canteen saturday | /canteen sunday

Running /canteen alone will default to /canteen today.

Valid ingredient commands look like /canteen ingredient burger.

You can also run /canteen help. The implementation of help commands is delegated to the service integrations rather than being handled by the core server.

Slack notifier

The Slackbot will also post the current day’s menu to a Slack channel on a schedule via an incoming webhook. The channel is configured during the installation process.

Alexa

The alexa function makes CanteenBot available via an Amazon Alexa skill, available here on the skill store.

The name of the skill is TNB Canteen and you can invoke it with news canteen. For example:

• "Alexa, open news canteen"
• "Alexa, ask news canteen what's for lunch today"
• "Alexa, ask news canteen what's on the menu tomorrow"

The Alexa skill does not currently support ingredient queries.

Serverless

The Serverless configuration is stored in serverless.yml.

Environment variables are stored in env.yml, which should not be committed to version control. A sample version of this file is included as env-sample.yml.

Development

Testing:

yarn test

Deployment:

serverless deploy

Contributing

Issues and pull requests are welcome!