feat(storage): add HTTP endpoint to get the config model

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

@@ -29,6 +29,7 @@ use super::proxies::{DevicesProxy, ProposalCalculatorProxy, ProposalProxy, Stora
 use super::StorageSettings;
 use crate::dbus::get_property;
 use crate::error::ServiceError;
+use serde_json::value::RawValue;
 use std::collections::HashMap;
 use zbus::fdo::ObjectManagerProxy;
 use zbus::names::{InterfaceName, OwnedInterfaceName};
@@ -160,6 +161,13 @@ impl<'a> StorageClient<'a> {
         Ok(settings)
     }
 
+    /// Get the storage config model according to the JSON schema
+    pub async fn get_config_model(&self) -> Result<Box<RawValue>, ServiceError> {
+        let serialized_config_model = self.storage_proxy.get_config_model().await?;
+        let config_model = serde_json::from_str(serialized_config_model.as_str()).unwrap();
+        Ok(config_model)
+    }
+
     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

@@ -47,6 +47,9 @@ trait Storage1 {
     /// Get the current storage solved config according to the JSON schema
     fn get_solved_config(&self) -> zbus::Result<String>;
 
+    /// Get the storage config model according to the JSON schema
+    fn get_config_model(&self) -> zbus::Result<String>;
+
     /// DeprecatedSystem property
     #[dbus_proxy(property)]
     fn deprecated_system(&self) -> zbus::Result<bool>;

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

@@ -39,6 +39,7 @@ use axum::{
     Json, Router,
 };
 use serde::{Deserialize, Serialize};
+use serde_json::value::RawValue;
 use tokio_stream::{Stream, StreamExt};
 use zfcp::{zfcp_service, zfcp_stream};
 
@@ -114,6 +115,7 @@ pub async fn storage_service(dbus: zbus::Connection) -> Result<Router, ServiceEr
     let router = Router::new()
         .route("/config", put(set_config).get(get_config))
         .route("/solved_config", get(get_solved_config))
+        .route("/config_model", get(get_config_model))
         .route("/probe", post(probe))
         .route("/devices/dirty", get(devices_dirty))
         .route("/devices/system", get(system_devices))
@@ -181,6 +183,30 @@ async fn get_solved_config(
     Ok(Json(settings))
 }
 
+/// Returns the storage config model.
+///
+/// * `state` : service state.
+#[utoipa::path(
+    get,
+    path = "/config_model",
+    context_path = "/api/storage",
+    operation_id = "get_storage_config_model",
+    responses(
+        (status = 200, description = "storage config model", body = Box<RawValue>),
+        (status = 400, description = "The D-Bus service could not perform the action")
+    )
+)]
+async fn get_config_model(
+    State(state): State<StorageState<'_>>,
+) -> Result<Json<Box<RawValue>>, Error> {
+    let config_model = state
+        .client
+        .get_config_model()
+        .await
+        .map_err(Error::Service)?;
+    Ok(Json(config_model))
+}
+
 /// Sets the storage configuration.
 ///
 /// * `state`: service state.