tod server

A server that schedules trips so that a notification can be sent when it's time to leave. This was designed to be used with the tod app. The server tracks trip duration in real-time using Google Maps so that transit information is updated and users are alerted so that they never miss their bus. Tod is short for 'time of departure'.

Google Maps does not offer real-time updates for all transit systems but the code is extensible so that additional systems can be added. See the Development section. Don't rely on this server for transit updates unless you're sure that Google Maps Directions offers regular updates to schedules in your city.

WARNING: This is a personal side project that is still in alpha development, you are responsible for your own appointments and this server will not be held accountable for any tardiness.

Dependencies

• Docker
• docker-compose

Usage

The tod server is made up of:

• Trip watcher (tripwatcher in docker-compose) - this watches trips to ensure that notifications are sent based on real-time data.
• Web server (todserver in docker-compose) - this schedules trips and returns search results to the client

These can be started by calling:

docker-compose build && docker-compose up

from the base directory. A Google Maps Directions API key as well as push notification configuration is required, see the Configuration section below.

Configuration

Before calling docker-compose up you will need to enter API keys into the command keys for each docker container in the docker-compose file. Like so:

  todserver:
    build:
      context: .
      dockerfile: Dockerfile
    ports: ["80:80"]
    links: ['postgres']
    command: todserver XXXXXXXXXXXXXXXXX

  tripwatcher:
    build:
      context: .
      dockerfile: tripwatcher/Dockerfile
    links: ['postgres']
    command: tripwatcher XXXXXXXXXXXXXXXXX

Where XXXXXXXXXXXXXXXXX is your Google Maps Directions API key. If you don't have a key see Directions API for more details.

You will also need to need to set up a config.yml in tripwatcher/. Here you'll configure the apikey key from Firebase for android and key_path for ios to point to a .p12 certificate for APNS.

You may also be required to specify a topic for APNS if setting the server up with a production certificate. The topic will be your bundle identifier. This should be set in tripwatcher/main.go in the sendNotification function.

Development

Tripwatcher works by regularly searching Google Maps for routes that match the user's query, if the trip duration suddenly takes a lot longer (due to traffic, for example) then the notification will be sent early. As another example, if the bus is running late, the notification will be delayed accordingly.

api/routes.go lists the basic API for routes and how the server will search for them using the RouteFinder interface. This is currently implemented in googlemaps.go using the GoogleMapsFinder implementation. This is then used in main.go and in tripwatcher/main.go but could easily be replaced for another data source.

Testing

All tests can be run using the command go test ./...

Database

The database is a Postgres database, this is configured via the init.sql file. All queries and commands run to the database are in api/postgres.go.

TODO

This is a list of features or issues I'd like to work on in the future.

• Setup APNS feedback service checks and Firebase Cloud Messaging uninstall check
• Add in an optional warning notification ten minutes before it's time to leave