COTA Google Maps Mashup

A Google Maps mashup with real-time bus information from COTA.

Visit https://joeshaw.org/cota-bus to see it in action.

This draws heavily from my MBTA mashup from 2009. The MBTA provides a JSON API which removes the need for any server side components, but COTA’s real-time data is only available via GTFS-realtime, a protobuf-based API. A Go server takes the (static, occasionally updated) GTFS data for COTA and updates it with periodic fetches of the GTFS-realtime data.

This module is pulled into my blog via git submodules.

Running the server

To build:

go build .

To run:

./cota-bus`

Configuration Options

The server supports the following command-line flags:

• -listen: HTTP listen address (default: :18080)
• -gtfs-url: URL to GTFS static feed (default: https://www.cota.com/data/cota.gtfs.zip)
• -trip-updates-url: URL to GTFS-realtime trip updates feed (default: https://gtfs-rt.cota.vontascloud.com/TMGTFSRealTimeWebService/TripUpdate/TripUpdates.pb)
• -vehicles-url: URL to GTFS-realtime vehicle positions feed (default: https://gtfs-rt.cota.vontascloud.com/TMGTFSRealTimeWebService/Vehicle/VehiclePositions.pb)

Development

If you need to regenerate code for an updated GTFS-realtime protobuf file, you can do so with:

go generate ./internal/realtime

This requires the protoc compiler and proto-gen-go plugin to be installed.

Run the tests with:

go test ./...