Implement a new configuration merging logic

rust/agama-files/src/service.rs

@@ -183,7 +183,11 @@ impl MessageHandler<message::SetConfig> for Service {
             self.add_scripts(scripts.clone()).await?;
         }
 
-        self.files = config.files;
+        if let Some(files) = config.files {
+            self.files = files;
+        } else {
+            self.files.clear();
+        }
 
         Ok(())
     }

rust/agama-lib/src/questions/http_client.rs

@@ -112,7 +112,7 @@ impl HTTPClient {
         answers: Vec<AnswerRule>,
     ) -> Result<(), QuestionsHTTPClientError> {
         let questions = QuestionsConfig {
-            answers,
+            answers: Some(answers),
             ..Default::default()
         };
         let config = Config {

rust/agama-manager/Cargo.toml

@@ -15,12 +15,12 @@ thiserror = "2.0.12"
 tokio = { version = "1.40.0", features = ["macros", "rt-multi-thread", "sync"] }
 async-trait = "0.1.83"
 zbus = { version = "5", default-features = false, features = ["tokio"] }
-merge-struct = "0.1.0"
 serde_json = "1.0.140"
 tracing = "0.1.41"
 serde = { version = "1.0.228", features = ["derive"] }
 serde_with = "3.16.1"
 gettext-rs = { version = "0.7.7", features = ["gettext-system"] }
+merge = "0.2.0"
 
 [dev-dependencies]
 test-context = "0.4.1"

rust/agama-manager/src/service.rs

@@ -34,7 +34,7 @@ use agama_utils::{
 };
 use async_trait::async_trait;
 use gettextrs::gettext;
-use merge_struct::merge;
+use merge::Merge;
 use network::NetworkSystemClient;
 use serde_json::Value;
 use std::sync::Arc;
@@ -44,8 +44,6 @@ use tokio::sync::{broadcast, RwLock};
 pub enum Error {
     #[error("Missing product")]
     MissingProduct,
-    #[error("Cannot merge the configuration")]
-    MergeConfig,
     #[error(transparent)]
     Event(#[from] broadcast::error::SendError<Event>),
     #[error(transparent)]
@@ -543,18 +541,6 @@ impl MessageHandler<message::SetConfig> for Service {
     }
 }
 
-fn merge_network(mut config: Config, update_config: Config) -> Config {
-    if let Some(network) = &update_config.network {
-        if let Some(connections) = &network.connections {
-            if let Some(ref mut config_network) = config.network {
-                config_network.connections = Some(connections.clone());
-            }
-        }
-    }
-
-    config
-}
-
 #[async_trait]
 impl MessageHandler<message::UpdateConfig> for Service {
     /// Patches the config.
@@ -563,9 +549,9 @@ impl MessageHandler<message::UpdateConfig> for Service {
     /// config, then it keeps the values from the current config.
     async fn handle(&mut self, message: message::UpdateConfig) -> Result<(), Error> {
         self.check_stage(Stage::Configuring).await?;
-        let config = merge(&self.config, &message.config).map_err(|_| Error::MergeConfig)?;
-        let config = merge_network(config, message.config);
-        self.update_config(config).await
+        let mut new_config = message.config;
+        new_config.merge(self.config.clone());
+        self.update_config(new_config).await
     }
 }
 

rust/agama-software/tests/zypp_server.rs

@@ -97,7 +97,7 @@ async fn test_start_zypp_server() {
     };
     let config = Config {
         policy: None,
-        answers: vec![rule],
+        answers: Some(vec![rule]),
     };
     question_handler
         .call(question::message::SetConfig::new(Some(config)))

rust/agama-utils/Cargo.toml

@@ -28,6 +28,7 @@ macaddr = { version = "1.0.1", features = ["serde_std"] }
 fs-err = "3.2.0"
 fluent-uri = { version = "0.4.1", features = ["serde"] }
 tempfile = "3.23.0"
+merge = "0.2.0"
 
 [dev-dependencies]
 test-context = "0.4.1"

rust/agama-utils/src/api/config.rs

@@ -23,10 +23,12 @@ use crate::api::{
     software::{self, ProductConfig},
     storage,
 };
+use merge::Merge;
 use serde::{Deserialize, Serialize};
 
-#[derive(Clone, Debug, Default, Deserialize, Serialize, utoipa::ToSchema)]
+#[derive(Clone, Debug, Default, Deserialize, Serialize, Merge, utoipa::ToSchema)]
 #[serde(rename_all = "camelCase")]
+#[merge(strategy = merge::option::recurse)]
 pub struct Config {
     #[serde(skip_serializing_if = "Option::is_none")]
     #[serde(alias = "localization")]

rust/agama-utils/src/api/files/config.rs

@@ -19,6 +19,7 @@
 // find current contact information at www.suse.com.
 
 use fluent_uri::Uri;
+use merge::Merge;
 use serde::{Deserialize, Serialize};
 
 use crate::api::files::{
@@ -27,16 +28,19 @@ use crate::api::files::{
     FileSourceError, WithFileSource,
 };
 
-#[derive(Clone, Debug, Default, Serialize, Deserialize, utoipa::ToSchema)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, Merge, utoipa::ToSchema)]
 pub struct Config {
-    #[serde(default, skip_serializing_if = "Vec::is_empty")]
-    pub files: Vec<UserFile>,
     #[serde(skip_serializing_if = "Option::is_none")]
+    #[merge(strategy = merge::option::overwrite_none)]
+    pub files: Option<Vec<UserFile>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    #[merge(strategy = merge::option::overwrite_none)]
     pub scripts: Option<ScriptsConfig>,
 }
 
-#[derive(Clone, Debug, Default, Serialize, Deserialize, utoipa::ToSchema)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, Merge, utoipa::ToSchema, PartialEq)]
 #[serde(rename_all = "camelCase")]
+#[merge(strategy = merge::option::overwrite_none)]
 pub struct ScriptsConfig {
     /// User-defined pre-installation scripts
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -88,3 +92,95 @@ impl ScriptsConfig {
         Ok(())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::api::files::{BaseScript, FileSource};
+
+    use super::*;
+
+    fn base_script(name: &str) -> BaseScript {
+        BaseScript {
+            name: name.to_string(),
+            source: FileSource::Text {
+                content: "".to_string(),
+            },
+        }
+    }
+
+    fn build_pre_script(name: &str) -> PreScript {
+        PreScript {
+            base: base_script(name),
+        }
+    }
+
+    #[test]
+    fn test_merge_with_default_scripts() {
+        let mut new_config = ScriptsConfig {
+            pre: Some(vec![build_pre_script("test")]),
+            ..Default::default()
+        };
+        new_config.merge(Default::default());
+
+        let pre_scripts = new_config.pre.unwrap();
+        assert_eq!(pre_scripts.len(), 1);
+    }
+
+    #[test]
+    fn test_merge_scripts() {
+        let original = ScriptsConfig {
+            pre: Some(vec![build_pre_script("test")]),
+            ..Default::default()
+        };
+
+        let mut updated = ScriptsConfig {
+            pre: Some(vec![build_pre_script("updated")]),
+            ..Default::default()
+        };
+
+        updated.merge(original);
+        let pre_scripts = updated.pre.unwrap();
+        assert_eq!(pre_scripts.len(), 1);
+        let script = pre_scripts.get(0).unwrap();
+        assert_eq!(&script.base.name, "updated");
+    }
+
+    #[test]
+    fn test_merge_files_config() {
+        let mut updated = Config {
+            files: Some(vec![UserFile {
+                destination: "/foo".to_string(),
+                ..Default::default()
+            }]),
+            scripts: Some(ScriptsConfig {
+                pre: Some(vec![build_pre_script("updated_pre")]),
+                ..Default::default()
+            }),
+        };
+
+        let original = Config {
+            files: Some(vec![UserFile {
+                destination: "/bar".to_string(),
+                ..Default::default()
+            }]),
+            scripts: Some(ScriptsConfig {
+                pre: Some(vec![build_pre_script("original_pre")]),
+                post: Some(vec![]),
+                ..Default::default()
+            }),
+        };
+
+        let updated_clone = updated.clone();
+        updated.merge(original);
+
+        // Assert for files (overwrite_none)
+        // `updated.files` is Some, so it is not overwritten.
+        assert_eq!(updated.files, updated_clone.files);
+
+        // Assert for scripts (overwrite_none on Option<ScriptsConfig>)
+        // `updated.scripts` is Some, so it is not overwritten.
+        assert_eq!(updated.scripts, updated_clone.scripts);
+        // The inner fields of `updated.scripts` should not have changed.
+        assert!(updated.scripts.as_ref().unwrap().post.is_none());
+    }
+}

rust/agama-utils/src/api/files/file_source.rs

@@ -33,7 +33,7 @@ pub enum FileSourceError {
     IO(#[from] std::io::Error),
 }
 
-#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema)]
+#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema, PartialEq)]
 #[serde(untagged)]
 /// Text or URL Reference of a config file or a script
 pub enum FileSource {

rust/agama-utils/src/api/files/scripts.rs

@@ -78,7 +78,7 @@ pub enum ScriptsGroup {
     Init,
 }
 
-#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema)]
+#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema, PartialEq)]
 pub struct BaseScript {
     pub name: String,
     #[serde(flatten)]
@@ -153,7 +153,7 @@ impl Script {
 }
 
 /// Represents a script that runs before the installation starts.
-#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema)]
+#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema, PartialEq)]
 pub struct PreScript {
     #[serde(flatten)]
     pub base: BaseScript,
@@ -179,7 +179,7 @@ impl TryFrom<Script> for PreScript {
 impl_with_file_source!(PreScript);
 
 /// Represents a script that runs after partitioning.
-#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema)]
+#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema, PartialEq)]
 pub struct PostPartitioningScript {
     #[serde(flatten)]
     pub base: BaseScript,
@@ -205,7 +205,7 @@ impl TryFrom<Script> for PostPartitioningScript {
 impl_with_file_source!(PostPartitioningScript);
 
 /// Represents a script that runs after the installation finishes.
-#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema)]
+#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema, PartialEq)]
 pub struct PostScript {
     #[serde(flatten)]
     pub base: BaseScript,
@@ -235,7 +235,7 @@ impl_with_file_source!(PostScript);
 
 /// Represents a script that runs during the first boot of the target system,
 /// once the installation is finished.
-#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema)]
+#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema, PartialEq)]
 pub struct InitScript {
     #[serde(flatten)]
     pub base: BaseScript,

rust/agama-utils/src/api/files/user_file.rs

@@ -43,7 +43,7 @@ pub enum Error {
 }
 
 /// Represents individual settings for single file deployment
-#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema)]
+#[derive(Clone, Debug, Serialize, Deserialize, utoipa::ToSchema, PartialEq)]
 #[serde(rename_all = "camelCase")]
 pub struct UserFile {
     /// File content or URL.