Connect with Rust
Below is an example using the paho.mqtt.rust crate with the TOKEN authentication mode configured on a Broker.
The example below creates a simple subscriber, sends a message to the configured topic, and waits until the message is received before exiting.
Make sure to set the BROKER_URI (e.g. mqtts://YOUR-BROKER.YOUR-NAMESPACE.cloudflarepubsub.com), BROKER_TOKEN (a valid auth token), and BROKER_TOPIC environmental variables before running the example program.
# in your Cargo.toml
paho-mqtt = "0.11.1"
Create a file called example.rs with the following content, and use cargo run to build and run the example:
use paho_mqtt::*;
use std::thread; fn main() { // Specify MQTT broker hostname: <broker name>.<namespace>.cloudflarepubsub.com let uri = std::env::var("BROKER_URI").expect("URI must be set"); // Your JWT token let jwt = std::env::var("BROKER_TOKEN").expect("JWT must be set"); // Specify a topic name let topic = std::env::var("BROKER_TOPIC").expect("Topic must be set"); // Configure the MQTT client let client_opts = CreateOptionsBuilder::new() .mqtt_version(MQTT_VERSION_5) .server_uri(uri) .finalize(); // Connect options let options = ConnectOptionsBuilder::new() .ssl_options(SslOptions::default()) .clean_start(true) .password(jwt) .finalize(); // Create the MQTT client let cli = Client::new(client_opts).expect("Error creating client"); // Connect to your broker cli.connect(options).expect("Error connecting to broker"); // Message receiver let rx = cli.start_consuming(); // Subscribe to a topic cli.subscribe(&topic, 0) .expect("Error subscribing to topic"); // Start waiting for messages let reader = thread::spawn(move || match rx.recv().expect("Error receiving message") { Some(message) => { println!("{:?}", message); } None => {} }); // Publish a message! cli.publish(Message::new(topic, "My first MQTT message", 0)) .expect("Error publishing"); // Wait until we have received our message let _ = reader.join(); // Good-Bye cli.disconnect(DisconnectOptions::default()) .expect("Error disconnecting");
}