storage: extend HTTP API to allow getting the solved config

- /api/storage/solved_config

rust/agama-lib/src/storage/client.rs

@@ -147,6 +147,13 @@ impl<'a> StorageClient<'a> {
         Ok(settings)
     }
 
+    /// Get the storage solved config according to the JSON schema
+    pub async fn get_solved_config(&self) -> Result<StorageSettings, ServiceError> {
+        let serialized_settings = self.storage_proxy.get_solved_config().await?;
+        let settings = serde_json::from_str(serialized_settings.as_str()).unwrap();
+        Ok(settings)
+    }
+
     pub async fn calculate(&self, settings: ProposalSettingsPatch) -> Result<u32, ServiceError> {
         Ok(self.calculator_proxy.calculate(settings.into()).await?)
     }

rust/agama-lib/src/storage/proxies.rs

@@ -44,6 +44,9 @@ trait Storage1 {
     /// Get the current storage config according to the JSON schema
     fn get_config(&self) -> zbus::Result<String>;
 
+    /// Get the current storage solved config according to the JSON schema
+    fn get_solved_config(&self) -> zbus::Result<String>;
+
     /// DeprecatedSystem property
     #[dbus_proxy(property)]
     fn deprecated_system(&self) -> zbus::Result<bool>;

rust/agama-server/src/storage/web.rs

@@ -113,6 +113,7 @@ pub async fn storage_service(dbus: zbus::Connection) -> Result<Router, ServiceEr
     let state = StorageState { client };
     let router = Router::new()
         .route("/config", put(set_config).get(get_config))
+        .route("/solved_config", get(get_solved_config))
         .route("/probe", post(probe))
         .route("/devices/dirty", get(devices_dirty))
         .route("/devices/system", get(system_devices))
@@ -155,6 +156,31 @@ async fn get_config(State(state): State<StorageState<'_>>) -> Result<Json<Storag
     Ok(Json(settings))
 }
 
+/// Returns the solved storage configuration.
+///
+/// * `state` : service state.
+#[utoipa::path(
+    get,
+    path = "/solved_config",
+    context_path = "/api/storage",
+    operation_id = "get_storage_solved_config",
+    responses(
+        (status = 200, description = "storage solved configuration", body = StorageSettings),
+        (status = 400, description = "The D-Bus service could not perform the action")
+    )
+)]
+async fn get_solved_config(
+    State(state): State<StorageState<'_>>,
+) -> Result<Json<StorageSettings>, Error> {
+    // StorageSettings is just a wrapper over serde_json::value::RawValue
+    let settings = state
+        .client
+        .get_solved_config()
+        .await
+        .map_err(Error::Service)?;
+    Ok(Json(settings))
+}
+
 /// Sets the storage configuration.
 ///
 /// * `state`: service state.