zeroconf is a cross-platform library that wraps underlying ZeroConf/mDNS implementations such as Bonjour or Avahi, providing an easy and idiomatic way to both register and browse services.

This crate provides the cross-platform MdnsService and MdnsBrowser available for each supported platform as well as platform-specific modules for lower-level access to the mDNS implementation should that be necessary.

Most users of this crate need only MdnsService and MdnsBrowser.

Examples

Register a service

When registering a service, you may optionally pass a "context" to pass state through the callback. The only requirement is that this context implements the Any trait, which most types will automatically. See MdnsService for more information about contexts.

use std::any::Any;
use std::sync::{Arc, Mutex};
use std::time::Duration;
use zeroconf::prelude::*;
use zeroconf::{MdnsService, ServiceRegistration, ServiceType, TxtRecord};

#[derive(Default, Debug)]
pub struct Context {
service_name: String,
}

fn main() {
let mut service = MdnsService::new(ServiceType::new("http", "tcp").unwrap(), 8080);
let mut txt_record = TxtRecord::new();
let context: Arc<Mutex<Context>> = Arc::default();

txt_record.insert("foo", "bar").unwrap();

service.set_registered_callback(Box::new(on_service_registered));
service.set_context(Box::new(context));
service.set_txt_record(txt_record);

let event_loop = service.register().unwrap();

loop {
// calling `poll()` will keep this service alive
event_loop.poll(Duration::from_secs(0)).unwrap();
}
}

fn on_service_registered(
result: zeroconf::Result<ServiceRegistration>,
context: Option<Arc<dyn Any>>,
) {
let service = result.unwrap();

println!("Service registered: {:?}", service);

let context = context
.as_ref()
.unwrap()
.downcast_ref::<Arc<Mutex<Context>>>()
.unwrap()
.clone();

context.lock().unwrap().service_name = service.name().clone();

println!("Context: {:?}", context);

// ...
}

Browsing services

use std::any::Any;
use std::sync::Arc;
use std::time::Duration;
use zeroconf::prelude::*;
use zeroconf::{MdnsBrowser, ServiceDiscovery, ServiceType};

fn main() {
let mut browser = MdnsBrowser::new(ServiceType::new("http", "tcp").unwrap());

browser.set_service_discovered_callback(Box::new(on_service_discovered));

let event_loop = browser.browse_services().unwrap();

loop {
// calling `poll()` will keep this browser alive
event_loop.poll(Duration::from_secs(0)).unwrap();
}
}

fn on_service_discovered(
result: zeroconf::Result<ServiceDiscovery>,
_context: Option<Arc<dyn Any>>,
) {
println!("Service discovered: {:?}", result.unwrap());

// ...
}