kylerchin / lacmta-alerts-to-protobuf

(Obsolete) Fetch LA Metro Alerts in Protobuf or Rust Structs, Written in rust

Los Angeles Protobuf Alerts

Los Angeles Metro did not share alerts with the public in the Protobuf format. However, the service alerts page json seems compatible. It is presented in Json format. I was able to convert it to Protobuf using the gtfs_rt crate.

Project was obsolete 63 hours later, LA Metro responded by publishing https://s3.amazonaws.com/la-alerts-prod/alerts.pb 🎉🎉🎉🎉🎉

My version of the feeds are hosted at

https://kactusapi.kylerchin.com/gtfsrt/?feed=f-metro~losangeles~bus~rt&category=alerts

and

https://kactusapi.kylerchin.com/gtfsrt/?feed=f-metro~losangeles~rail~rt&category=alerts

Human Readable json:

https://kactusapi.kylerchin.com/gtfsrtasjson/?feed=f-metro~losangeles~bus~rt&category=alerts https://kactusapi.kylerchin.com/gtfsrtasjson/?feed=f-metro~losangeles~rail~rt&category=alerts

Running the binary

The runtime bin/main.rs is a script that runs req_into_split_feeds_bytes() every 10 seconds and inserts the compressed protobuf bytes into redis keys gtfsrt|f-metro~losangeles~rail~rt|alerts and gtfsrt|f-metro~losangeles~rail~rt|alerts

This is compatible with the kylerchin/kactus-gtfs-rt server. It can be published as a web API using the kactus server.

using the raw functions in your own project

if you want to integrate this into your own project and not use the redis cache, here are the functions in the library.

download_to_structure() puts the entire alert into a single gtfs_rt::FeedMessage

req_into_split_feeds() calls download_to_structure() and splits it into a struct

pub struct SplitFeeds {
    pub bus: gtfs_rt::FeedMessage,
    pub rail: gtfs_rt::FeedMessage,
}

req_into_split_feeds_bytes() calls req_into_split_feeds() but is the compressed protobuf version

pub struct split_feeds_bytes {
    pub bus: Vec<u8>,
    pub rail: Vec<u8>,
}