Londibot

Bot which reports the status of London TFL services.

What is Londibot?

Londibot started as a wrapper around the TFL API so I could get aquainted with Clojure when I first arrived to London (Autumn 2018). As I spent more time in the city, I realized that the public transport services were slightly underwhelming – it's not unusual for any underground line to suffer delays a couple of times a day. That's when I decided that the TFL API wrapper could actually be so much more and help me with that struggle.

Currently, Londibot is a Telegram/Slack bot which allows users to subscribe to any underground/overground line so it notifies them upon any service change, be it a disruption or a recovery. It supports a wide variety of commands, all the way from /status to /subscribe Victoria, Metropolitan. More on this below.

And technically, how is it structured?

Currently Londibot runs as a Phoenix application. It's divided between all the core logic under the londibot directory and all the web stuffs under londibot_web. Furthermore, the core business logic under londibot is presented under the following structure:

• TFL, takes care of connecting via HTTP with the TFL API and adding the logic of which statuses are good, bad, etc.
• Subscriptions, is in charge of handling user subscriptions to lines. It saves and queries them.
• Notifications is one of the bigger blocks. It contains the different wrappers for the Slack/Telegram messaging APIs as well as a worker which polls TFL and discerns when to send a message or not.
• Commands contains the logic to be executed for each command sent to the bot.

Using Londibot

Currently Londibot supports multiple commands, slightly different across services to improve UX.

Telegram

In case you're using the Telegram bot, different slash commands have been provided to make the bot more discoverable.

• /status will respond with a brief summary of all lines' status, like the dashboard you can find in the subway.
• /disruptions will respond just with the current disruptions in all the transport network
• /subscriptions will respond with a list of lines to which you are subscribed
• /subscribe circle, london overground will subscribe to the given lines
• /unsubscribe victoria, northern will unsubscribe to the given lines

Slack

To use Londibot via Slack, a slash command has been set up: /londibot. I have opted for having a single slash command since often Slack installations will have many bots and having too many slash commands ends up in being more confusing.

• /londibot status will respond with a brief summary of all lines' status, like the dashboard you can find in the subway.
• /londibot disruptions will respond just with the current disruptions in all the transport network
• /londibot subscriptions will respond with a list of lines to which you are subscribed
• /londibot subscribe circle, london overground will subscribe to the given lines
• /londibot unsubscribe victoria, northern will unsubscribe to the given lines

Getting started

To start the server:

• Install dependencies with mix deps.get
• Create and migrate your database with mix ecto.setup
• Install Node.js dependencies with cd assets && npm install
• Start the server with mix phx.server

Now you can visit localhost:4000 from your browser or run some sample requests like in sample_requests.http.

To run the tests, run: mix test.

Setting up the DB

To save user subscriptions, I've decided to go with Postgres (PG). Before continuing, make sure you have a running instance in your computer. In case you're running MacOS, I find it very convenient to use homebrew services to start and stop the DB:

Starting PG: brew services start postgresql Stoping PG: brew services stop postgresql

Once you have the PG up and running, to create the DB run: mix ecto.create && mix ecto.migrate (make sure to have a user postgres without password and superuser role).