client: Add IoTHubClientBuilder::pnp_model_id()

The idea with PNP is that connecting devices can announce a model ID which should be a valid DTMI when connecting. This functionality is only really supported for MQTT. The IoTHubClientBuilder accepts a str that it attempts to turn into a Dtmi instance which can only be constructed if it passes validation.
damienpontifex · Oct 6, 2021 · f9d3f5d · f9d3f5d
1 parent 05226a6
commit f9d3f5d
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Showing 2 changed files with 31 additions and 4 deletions.
diff --git a/src/client.rs b/src/client.rs
@@ -1,3 +1,4 @@
+use crate::dtmi::Dtmi;
 use crate::message::Message;
 #[cfg(feature = "direct-methods")]
 use crate::DirectMethodResponse;
@@ -91,6 +92,7 @@ impl IoTHubClient {
             device_id,
             token_source,
             root_ca: None,
+            pnp_model_id: None,
         }
     }
 
@@ -207,6 +209,7 @@ pub struct IoTHubClientBuilder<TS> {
     device_id: String,
     token_source: TS,
     root_ca: Option<native_tls::Certificate>,
+    pnp_model_id: Option<Dtmi>,
 }
 
 impl<TS: TokenSource + Send + Sync + Clone + 'static> IoTHubClientBuilder<TS> {
@@ -219,12 +222,18 @@ impl<TS: TokenSource + Send + Sync + Clone + 'static> IoTHubClientBuilder<TS> {
             device_id,
             token_source,
             root_ca,
+            pnp_model_id,
         } = self;
 
         #[cfg(not(feature = "https-transport"))]
-        let transport =
-            ClientTransport::new(&hub_name, device_id.clone(), token_source.clone(), root_ca)
-                .await?;
+        let transport = ClientTransport::new(
+            &hub_name,
+            device_id.clone(),
+            token_source.clone(),
+            root_ca,
+            pnp_model_id,
+        )
+        .await?;
         #[cfg(feature = "https-transport")]
         let transport =
             ClientTransport::new(&hub_name, device_id.clone(), token_source.clone()).await?;
@@ -243,4 +252,13 @@ impl<TS: TokenSource + Send + Sync + Clone + 'static> IoTHubClientBuilder<TS> {
         self.root_ca = Some(root_ca);
         Ok(self)
     }
+
+    /// Provide a PNP model ID
+    ///
+    /// Is only use with MQTT transport
+    pub fn pnp_model_id(mut self, pnp_model_id: impl AsRef<str>) -> crate::Result<Self> {
+        let dtmi = pnp_model_id.as_ref().parse()?;
+        self.pnp_model_id = Some(dtmi);
+        Ok(self)
+    }
 }
diff --git a/src/mqtt_transport.rs b/src/mqtt_transport.rs
@@ -24,6 +24,7 @@ use tokio_native_tls::{TlsConnector, TlsStream};
 
 use async_trait::async_trait;
 
+use crate::dtmi::Dtmi;
 use crate::message::Message;
 #[cfg(any(
     feature = "direct-methods",
@@ -204,11 +205,19 @@ impl MqttTransport {
         device_id: String,
         token_source: TS,
         root_ca: Option<native_tls::Certificate>,
+        pnp_model_id: Option<Dtmi>,
     ) -> crate::Result<Self>
     where
         TS: TokenSource + Send + Sync + 'static,
     {
-        let user_name = format!("{}/{}/?api-version=2018-06-30", hub_name, device_id);
+        let user_name = if let Some(Dtmi(model_id)) = pnp_model_id {
+            format!(
+                "{}/{}/?api-version=2020-09-30&model-id={}",
+                hub_name, device_id, model_id
+            )
+        } else {
+            format!("{}/{}/?api-version=2018-06-30", hub_name, device_id)
+        };
 
         let expiry = Utc::now() + Duration::days(1);
         trace!("Generating token that will expire at {}", expiry);