service: improve the resuability of create_daemon

service/src/singleton.rs

@@ -19,7 +19,7 @@ use crate::daemon::{
     NydusDaemon,
 };
 use crate::fs_service::FsService;
-use crate::{Error, Result, ServiceArgs};
+use crate::{Error, Result};
 
 #[allow(dead_code)]
 struct ServiceController {
@@ -98,9 +98,10 @@ impl ServiceController {
 
 #[cfg(target_os = "linux")]
 impl ServiceController {
-    fn initialize_fscache_service<T: ServiceArgs>(
+    fn initialize_fscache_service(
         &self,
-        args: &T,
+        tag: Option<&str>,
+        threads: Option<&str>,
         path: &str,
     ) -> std::io::Result<()> {
         // Validate --fscache option value is an existing directory.
@@ -124,9 +125,8 @@ impl ServiceController {
                 return Err(einval!("--fscache option contains invalid characters"));
             }
         };
-        let tag = args.value_of("fscache-tag").map(|s| s.as_str());
 
-        let threads = if let Some(threads_value) = args.value_of("fscache-threads") {
+        let threads = if let Some(threads_value) = threads {
             crate::validate_threads_configuration(threads_value).map_err(|err| einval!(err))?
         } else {
             1usize
@@ -237,26 +237,17 @@ impl DaemonStateMachineSubscriber for ServiceController {
 }
 
 /// Create and start a Nydus daemon to host fscache and fusedev services.
-///
-/// The `args` argument is derived from commandline options and controls services enabled.
-/// The fscache service will be enabled if `args` contains the `--fscache` argument.
-pub fn create_daemon<T: ServiceArgs>(
-    args: &T,
+#[allow(clippy::too_many_arguments)]
+pub fn create_daemon(
+    id: Option<String>,
+    supervisor: Option<String>,
+    fscache: Option<&str>,
+    tag: Option<&str>,
+    threads: Option<&str>,
+    config: Option<serde_json::Value>,
     bti: BuildTimeInfo,
     waker: Arc<Waker>,
 ) -> std::io::Result<Arc<dyn NydusDaemon>> {
-    let id = args.value_of("id").map(|id| id.to_string());
-    let supervisor = args.value_of("supervisor").map(|s| s.to_string());
-    let config = match args.value_of("config") {
-        None => None,
-        Some(path) => {
-            let config = std::fs::read_to_string(path)?;
-            let config: serde_json::Value = serde_json::from_str(&config)
-                .map_err(|_e| einval!("invalid configuration file"))?;
-            Some(config)
-        }
-    };
-
     let (to_sm, from_client) = channel::<DaemonStateMachineInput>();
     let (to_client, from_sm) = channel::<Result<()>>();
     let service_controller = ServiceController {
@@ -277,8 +268,8 @@ pub fn create_daemon<T: ServiceArgs>(
 
     service_controller.initialize_blob_cache(&config)?;
     #[cfg(target_os = "linux")]
-    if let Some(path) = args.value_of("fscache") {
-        service_controller.initialize_fscache_service(args, path)?;
+    if let Some(path) = fscache {
+        service_controller.initialize_fscache_service(tag, threads, path)?;
     }
 
     let daemon = Arc::new(service_controller);

src/bin/nydusd/main.rs

@@ -553,8 +553,32 @@ fn process_singleton_arguments(
     _apisock: Option<&str>,
     bti: BuildTimeInfo,
 ) -> Result<()> {
+    let id = subargs.value_of("id").map(|id| id.to_string());
+    let supervisor = subargs.value_of("supervisor").map(|s| s.to_string());
+    let config = match subargs.value_of("config") {
+        None => None,
+        Some(path) => {
+            let config = std::fs::read_to_string(path)?;
+            let config: serde_json::Value = serde_json::from_str(&config)
+                .map_err(|_e| einval!("invalid configuration file"))?;
+            Some(config)
+        }
+    };
+    let fscache = subargs.value_of("fscache").map(|s| s.as_str());
+    let tag = subargs.value_of("fscache-tag").map(|s| s.as_str());
+    let threads = subargs.value_of("fscache-threads").map(|s| s.as_str());
     info!("Start Nydus daemon in singleton mode!");
-    let daemon = create_daemon(subargs, bti, DAEMON_CONTROLLER.alloc_waker()).map_err(|e| {
+    let daemon = create_daemon(
+        id,
+        supervisor,
+        fscache,
+        tag,
+        threads,
+        config,
+        bti,
+        DAEMON_CONTROLLER.alloc_waker(),
+    )
+    .map_err(|e| {
         error!("Failed to start singleton daemon: {}", e);
         e
     })?;