emulator

emulator(address) points every client of the broker at a local Pub/Sub emulator, with anonymous credentials.

The address is either a host:port, which the broker dials over plaintext, or a URL such as http://localhost:8085, which it dials as written. The Google client libraries for Rust do not read PUBSUB_EMULATOR_HOST, so the address is a setting of the broker. With an emulator set, the endpoint and the credentials steps have no effect.

The emulator accepts any project id and starts empty. A subscription that creates itself with create_with_topic is the usual form against it. The emulator keeps its topics and subscriptions until it stops, so a second run finds what the first one created. The repository's stand is docker-compose.test.yml, which just brokers-up starts on port 8085.

Example

The service runs against the emulator at localhost:8085. Its test runs the same service in process, and against the emulator when PUBSUB_TEST_HOST names one.

Macros

examples/pubsub_broker_emulator.rs

/// The emulator at `host`, a `host:port` without a scheme.
fn broker(host: &str) -> PubSubBroker {
    PubSubBroker::new("my-project").emulator(host)
}

#[ruststream::app]
fn app() -> impl App<State = ()> {
    service(broker("localhost:8085"))
}

Manual

examples/manual/pubsub_broker_emulator.rs

/// The emulator at `host`, a `host:port` without a scheme.
fn broker(host: &str) -> PubSubBroker {
    PubSubBroker::new("my-project").emulator(host)
}

fn app() -> impl App<State = ()> {
    service(broker("localhost:8085"))
}