fix: c8y mapper config should use the value of c8y.mqtt as mqtt endpoint

When C8yMapperConfig is constructed from tedge config, by mistake, the
http endpoint was used as the mqtt endpoint.

Signed-off-by: Rina Fujino <rina.fujino.23@gmail.com>

Author: rina23q

crates/extensions/c8y_mapper_ext/src/config.rs

@@ -171,6 +171,7 @@ impl C8yMapperConfig {
         let device_topic_id = EntityTopicId::from_str(&tedge_config.mqtt.device_topic_id)?;
         let service = tedge_config.service.clone();
         let c8y_host = c8y_config.http.or_config_not_set()?.to_string();
+        let c8y_mqtt = c8y_config.mqtt.or_config_not_set()?.to_string();
         let tedge_http_address = tedge_config.http.client.host.clone();
         let tedge_http_port = tedge_config.http.client.port;
         let mqtt_schema = MqttSchema::with_root(tedge_config.mqtt.topic_root.clone());
@@ -237,8 +238,8 @@ impl C8yMapperConfig {
             device_topic_id,
             device_type,
             service,
-            c8y_host.clone(),
             c8y_host,
+            c8y_mqtt,
             tedge_http_host,
             topics,
             capabilities,

crates/extensions/c8y_mapper_ext/src/operations/handlers/config_update.rs

@@ -138,6 +138,54 @@ mod tests {
         .await;
     }
 
+    #[tokio::test]
+    async fn mapper_replaces_remote_url_with_proxy_url_3545() {
+        let ttd = TempTedgeDir::new();
+        let config = C8yMapperConfig {
+            c8y_host: "my.custom.domain.com:443".into(),
+            c8y_mqtt: "t12345.cumulocity.com:8883".into(),
+            ..test_mapper_config(&ttd)
+        };
+        let test_handle = spawn_c8y_mapper_actor_with_config(&ttd, config, true).await;
+        let TestHandle { mqtt, .. } = test_handle;
+        let mut mqtt = mqtt.with_timeout(TEST_TIMEOUT_MS);
+
+        skip_init_messages(&mut mqtt).await;
+
+        // Simulate c8y_DownloadConfigFile operation delivered via JSON over MQTT
+        mqtt.send(MqttMessage::new(
+            &C8yDeviceControlTopic::topic(&"c8y".try_into().unwrap()),
+            json!({
+                "id": "123456",
+                "c8y_DownloadConfigFile": {
+                    "type": "path/config/A",
+                    "url": "https://t12345.cumulocity.com/inventory/binaries/654321"
+                },
+                "externalSource": {
+                    "externalId": "test-device",
+                    "type": "c8y_Serial"
+                }
+            })
+            .to_string(),
+        ))
+        .await
+        .expect("Send failed");
+
+        assert_received_includes_json(
+            &mut mqtt,
+            [(
+                "te/device/main///cmd/config_update/c8y-mapper-123456",
+                json!({
+                    "status": "init",
+                    "remoteUrl": "http://127.0.0.1:8001/c8y/inventory/binaries/654321",
+                    "serverUrl": "https://t12345.cumulocity.com/inventory/binaries/654321",
+                    "type": "path/config/A",
+                }),
+            )],
+        )
+        .await;
+    }
+
     #[tokio::test]
     async fn mapper_converts_config_download_op_for_child_device() {
         let ttd = TempTedgeDir::new();