feat: Improve the mdns support

- Do not try to instantiate it if the thing is listening on localhost.
- Do not pass again unspec if that's the ip selected (e.g. 0.0.0.0 on
  ipv4)
- Make the example take the address as argument to make simpler to test
  it.

Cargo.toml

@@ -9,10 +9,10 @@ keywords = ["wot", "WebofThings"]
 
 [dependencies]
 wot-td = "0.3.1"
-mdns-sd = "0.10.1"
+mdns-sd = "0.11.0"
 thiserror = "1.0"
 if-addrs = "0.11.0"
-hostname = "0.3"
+hostname = "0.4"
 axum = "0.7.2"
 serde = "1.0.141"
 serde_json = "1.0.83"

examples/thing.rs

@@ -24,10 +24,14 @@ impl ExtendableThing for A {
 
 #[tokio::main]
 async fn main() {
+    let addr = std::env::args()
+        .nth(1)
+        .unwrap_or_else(|| "0.0.0.0:8080".into());
+
     let servient = Servient::builder("TestThing")
         .ext(A {})
         .finish_extend()
-        .http_bind("127.0.0.1:8080".parse().unwrap())
+        .http_bind(addr.parse().unwrap())
         .property("hello", |b| {
             b.ext(())
                 .ext_interaction(())
@@ -66,7 +70,7 @@ async fn main() {
         .build_servient()
         .unwrap();
 
-    eprintln!("Listening to 127.0.0.1:8080");
+    eprintln!("Listening to {addr}");
     dbg!(&servient.router);
 
     println!("Running the servient for 10 seconds.");

src/advertise.rs

@@ -81,6 +81,16 @@ pub struct ServiceBuilder<'a> {
     name: String,
 }
 
+fn normalize_hostname(mut hostname: String) -> String {
+    if !hostname.ends_with(".local") {
+        hostname.push_str(".local");
+    }
+    if !hostname.ends_with('.') {
+        hostname.push('.')
+    }
+    hostname
+}
+
 impl<'a> ServiceBuilder<'a> {
     fn new(ad: &'a Advertiser, name: impl Into<String>) -> ServiceBuilder<'a> {
         Self {
@@ -121,7 +131,7 @@ impl<'a> ServiceBuilder<'a> {
 
     /// The hostname used by the MDNS daemon.
     pub fn hostname(mut self, host: impl Into<String>) -> Self {
-        self.hostname = host.into();
+        self.hostname = normalize_hostname(host.into());
 
         self
     }
@@ -175,10 +185,7 @@ impl Advertiser {
     pub fn new() -> Result<Self> {
         let mdns = ServiceDaemon::new()?;
 
-        let mut hostname = hostname::get()?.to_string_lossy().to_string();
-        if !hostname.ends_with(".local") {
-            hostname.push_str(".local");
-        }
+        let hostname = normalize_hostname(hostname::get()?.to_string_lossy().to_string());
 
         let ips = if_addrs::get_if_addrs()?
             .iter()
@@ -224,7 +231,7 @@ mod test {
                 let props = info.get_properties();
                 assert_eq!(props.get_property_val_str("td"), Some(WELL_KNOWN));
                 assert_eq!(props.get_property_val_str("type"), Some("Thing"));
-                assert_eq!(info.get_hostname(), "testhost.");
+                assert_eq!(info.get_hostname(), "testhost.local.");
             },
         );
     }

src/servient.rs

@@ -113,11 +113,20 @@ impl Servient<Nil> {
 impl<O: ExtendableThing> Servient<O> {
     /// Start a listening server and advertise for it.
     pub async fn serve(&self) -> Result<(), Error> {
-        self.sd
-            .add_service(&self.name)
-            .thing_type(self.thing_type)
-            .port(self.http_addr.port())
-            .build()?;
+        let ip = self.http_addr.ip();
+
+        if !ip.is_loopback() {
+            let mut ad = self
+                .sd
+                .add_service(&self.name)
+                .thing_type(self.thing_type)
+                .port(self.http_addr.port());
+
+            if !ip.is_unspecified() {
+                ad = ad.ips([ip]);
+            }
+            ad.build()?;
+        }
 
         let listener = tokio::net::TcpListener::bind(&self.http_addr)
             .await