do not export empty defaults for user

rust/agama-lib/src/dbus.rs

@@ -101,6 +101,15 @@ pub fn extract_id_from_path(path: &OwnedObjectPath) -> Result<u32, zvariant::Err
         })
 }
 
+// small helper to convert dbus empty string to None
+pub fn optional_string(value: String) -> Option<String> {
+    if value.is_empty() {
+        None
+    } else {
+        Some(value)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::collections::HashMap;

rust/agama-lib/src/users/settings.rs

@@ -26,8 +26,9 @@ use serde::{Deserialize, Serialize};
 #[derive(Debug, Default, Serialize, Deserialize, PartialEq)]
 #[serde(rename_all = "camelCase")]
 pub struct UserSettings {
-    #[serde(rename = "user")]
+    #[serde(rename = "user", skip_serializing_if = "Option::is_none")]
     pub first_user: Option<FirstUserSettings>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub root: Option<RootUserSettings>,
 }
 
@@ -38,15 +39,34 @@ pub struct UserSettings {
 #[serde(rename_all = "camelCase")]
 pub struct FirstUserSettings {
     /// First user's full name
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub full_name: Option<String>,
     /// First user's username
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub user_name: Option<String>,
     /// First user's password (in clear text)
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub password: Option<String>,
     /// Whether the password is hashed or is plain text
+    #[serde(skip_serializing_if = "Self::skip_hashed")]
     pub hashed_password: Option<bool>,
 }
 
+impl FirstUserSettings {
+    // as dbus provides only boolean it is hard to distinguish
+    // false and not set. So act for false like not set as it is default.
+    fn skip_hashed(value: &Option<bool>) -> bool {
+        *value == Some(false)
+    }
+
+    pub fn skip_export(&self) -> bool {
+        self.full_name.is_none()
+            && self.user_name.is_none()
+            && self.password.is_none()
+            && Self::skip_hashed(&self.hashed_password)
+    }
+}
+
 /// Root user settings
 ///
 /// Holds the settings for the root user.
@@ -63,3 +83,9 @@ pub struct RootUserSettings {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub ssh_public_key: Option<String>,
 }
+
+impl RootUserSettings {
+    pub fn skip_export(&self) -> bool {
+        self.password.is_none() && self.hashed_password.is_none() && self.ssh_public_key.is_none()
+    }
+}

rust/agama-lib/src/users/store.rs

@@ -20,6 +20,7 @@
 
 use super::{FirstUser, FirstUserSettings, RootUserSettings, UserSettings, UsersHTTPClient};
 use crate::base_http_client::BaseHTTPClient;
+use crate::dbus::optional_string;
 use crate::error::ServiceError;
 
 /// Loads and stores the users settings from/to the D-Bus service.
@@ -43,21 +44,32 @@ impl UsersStore {
     pub async fn load(&self) -> Result<UserSettings, ServiceError> {
         let first_user = self.users_client.first_user().await?;
         let first_user = FirstUserSettings {
-            user_name: Some(first_user.user_name),
-            full_name: Some(first_user.full_name),
-            password: Some(first_user.password),
+            user_name: optional_string(first_user.user_name),
+            full_name: optional_string(first_user.full_name),
+            password: optional_string(first_user.password),
+            // sadly for boolean we do not have on dbus way to set it to not_set
             hashed_password: Some(first_user.hashed_password),
         };
+        let first_user = if first_user.skip_export() {
+            None
+        } else {
+            Some(first_user)
+        };
         let root_user = self.users_client.root_user().await?;
         let root_user = RootUserSettings {
             password: root_user.password,
             hashed_password: root_user.hashed_password,
             ssh_public_key: root_user.ssh_public_key,
         };
+        let root_user = if root_user.skip_export() {
+            None
+        } else {
+            Some(root_user)
+        };
 
         Ok(UserSettings {
-            first_user: Some(first_user),
-            root: Some(root_user),
+            first_user: first_user,
+            root: root_user,
         })
     }