bessersmith

Transform the custom MONO JSON feed (mono/# at mqtt.hsl.fi) into GTFS Realtime TripUpdates.

Instructions

To install:

git clone https://github.com/hsldevcom/bessersmith
cd bessersmith
yarn install

To test:

yarn test

To run:

# Some configuration must be given, see below.
yarn start

Configuration

The included configuration file template contains all of the intended configuration options. The absolute minimum fields that must be provided are marked with a comment # Required above the name of the field. They may be provided as environment variables, as well.

Configuration priority, higher overrides lower:

1. A configuration file whose path is given as a command line option.
2. Environment variables except for CONFIG_PATH.
3. A configuration file whose path is given by the environment variable CONFIG_PATH. If a configuration file has been specified via a command line option, CONFIG_PATH is ignored.

E.g. yarn start -c config.yaml excludes any bessersmith-specific environment variables from being used.

Some configuration must be given, none is hardcoded. A configuration file is not strictly necessary.

A handy configuration pattern for deployment:

1. Copy config.yaml and replace the dummy values, especially the secrets like ClientIds, usernames and passwords.
2. Deliver the new configuration file into Docker Swarm as a secret.
3. Point CONFIG_PATH to the secret. Do not use the command line option -c.
4. Override the non-secret values with the other environment variables as usual in the CI/CD pipeline.

The list of environment variables used by bessersmith:

• CONFIG_PATH: The path to the configuration file.
• BUNYAN_NAME: The value for the field name in bunyan log messages.
• BUNYAN_LEVEL: The logging level used by bunyan. Currently one of fatal, error, warn, info, debug or trace.
• MQTT_SUB_URL: The URL of the MQTT broker used for subscribing. The string is given to the connect function in MQTT.js. Currently one of the following protocols must be used: mqtt, mqtts, tcp, tls, ws or wss.
• MQTT_SUB_PORT: The port for the MQTT broker used for subscribing.
• MQTT_SUB_CLIENT_ID: The ClientId for the subscribing connection. Make sure this differs from all other ClientIds, e.g. by using a random suffix.
• MQTT_SUB_CLEAN: A boolean on whether to use a clean session for subscribing. With false bessersmith asks for a persistent session.
• MQTT_SUB_RECONNECT_PERIOD: The interval in milliseconds between consecutive reconnection attempts for the subscribing connection.
• MQTT_SUB_USERNAME: The username for the subscribing connection.
• MQTT_SUB_PASSWORD: The password for the subscribing connection.
• MQTT_SUB_QOS: The Quality of Service level that bessersmith should subscribe with.
• MQTT_SUB_TOPIC: The topic that bessersmith should subscribe to to get the custom MONO JSON messages.
• MQTT_PUB_URL: The URL of the MQTT broker used for publishing. Running a broker on localhost may get useful.
• MQTT_PUB_PORT: The port for the MQTT broker used for publishing.
• MQTT_PUB_CLIENT_ID: The ClientId for the publishing connection. Make sure this differs from all other ClientIds, as well.
• MQTT_PUB_CLEAN: A boolean on whether to use a clean session for publishing.
• MQTT_PUB_RECONNECT_PERIOD: The interval in milliseconds between consecutive reconnection attempts for the publishing connection.
• MQTT_PUB_USERNAME: The username for the publishing connection.
• MQTT_PUB_PASSWORD: The password for the publishing connection.
• MQTT_PUB_QOS: The Quality of Service level that bessersmith should publish with.
• MQTT_PUB_TOPIC: The topic into which bessersmith should publish GTFS Realtime TripUpdates.
• MQTT_PUB_LOG_INTERVAL_IN_SECONDS: The interval for logging the amount of sent MQTT packets over the publishing connection.
• CACHE_TTL_IN_SECONDS: The time to live in seconds for any entry in the trip cache.
• PROTO_PATH: The path to the GTFS Realtime protocol buffer schema file.