name

#[subscriber(GooglePubSub)] fixes the kind of subscription, and name at the mount site leaves its name to the deployment.

A handler written with the bare kind has no subscription yet. .name("orders-workers") where it is mounted builds the descriptor, as GooglePubSub::new would. A definition mounted without a name does not compile. The descriptor built this way keeps every default; a subscription with settings of its own is a descriptor in the attribute. The same handler serves several deployments that each read a subscription of their own, such as one per region. The manual form starts from Unnamed::<GooglePubSub>::new() and takes the same .name(..) step.

Example

Each deployment names its subscription in ORDERS_SUBSCRIPTION.

Macros
Manual

examples/pubsub_subscriptions_name.rs
/// A Pub/Sub subscription whose name the deployment decides.
#[subscriber(GooglePubSub)]
async fn place(order: &Order) -> HandlerOutcome {
    tracing::info!(order.id, "order placed");
    HandlerOutcome::ack()
}

/// One service per region, each reading the subscription of its region.
fn service(subscription: String) -> impl App<State = ()> {
    RustStream::new(AppInfo::new("orders", "0.1.0")).with_broker(
        PubSubBroker::new("my-project"),
        |b| {
            b.include(place.name(subscription));
        },
    )
}

examples/manual/pubsub_subscriptions_name.rs
/// A Pub/Sub subscription whose name the deployment decides.
struct Place;

impl Handle<Order> for Place {
    fn handle(
        &self,
        order: &Order,
        _outs: &(),
        _ctx: &mut Context<'_>,
    ) -> impl Future<Output = Result<(), HandlerOutcome>> {
        tracing::info!(order.id, "order placed");
        ready(Ok(()))
    }
}

/// One service per region, each reading the subscription of its region.
fn service(subscription: String) -> impl App<State = ()> {
    RustStream::new(AppInfo::new("orders", "0.1.0")).with_broker(
        PubSubBroker::new("my-project"),
        |b| {
            b.include(
                subscriber(Unnamed::<GooglePubSub>::new(), Place)
                    .name(subscription)
                    .build(),
            );
        },
    )
}

Example​

Example