add numa service restart command

Kills the running process and lets launchd/systemd respawn it
with the updated binary. DNS stays configured throughout.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/main.rs

@@ -14,8 +14,8 @@ use numa::override_store::OverrideStore;
 use numa::query_log::QueryLog;
 use numa::stats::ServerStats;
 use numa::system_dns::{
-    discover_system_dns, install_service, install_system_dns, service_status, uninstall_service,
+    discover_system_dns, install_service, install_system_dns, restart_service, service_status,
-    uninstall_system_dns,
+    uninstall_service, uninstall_system_dns,
 };
 
 #[tokio::main]
@@ -41,9 +41,10 @@ async fn main() -> numa::Result<()> {
             return match sub.as_str() {
                 "start" => install_service().map_err(|e| e.into()),
                 "stop" => uninstall_service().map_err(|e| e.into()),
+                "restart" => restart_service().map_err(|e| e.into()),
                 "status" => service_status().map_err(|e| e.into()),
                 _ => {
-                    eprintln!("Usage: numa service <start|stop|status>");
+                    eprintln!("Usage: numa service <start|stop|restart|status>");
                     Ok(())
                 }
             };
@@ -57,6 +58,7 @@ async fn main() -> numa::Result<()> {
             eprintln!("  uninstall       Restore original system DNS settings");
             eprintln!("  service start   Install as system service (auto-start on boot)");
             eprintln!("  service stop    Uninstall the system service");
+            eprintln!("  service restart Restart the service with updated binary");
             eprintln!("  service status  Check if the service is running");
             eprintln!("  help            Show this help");
             eprintln!();

src/system_dns.rs

@@ -416,6 +416,37 @@ pub fn uninstall_service() -> Result<(), String> {
     }
 }
 
+/// Restart the service (kill process, launchd/systemd auto-restarts with new binary).
+pub fn restart_service() -> Result<(), String> {
+    #[cfg(target_os = "macos")]
+    {
+        let output = std::process::Command::new("launchctl")
+            .args(["list", PLIST_LABEL])
+            .output();
+        match output {
+            Ok(o) if o.status.success() => {
+                // Service is loaded — kill the process, launchd restarts it
+                let _ = std::process::Command::new("pkill")
+                    .args(["-f", "/usr/local/bin/numa"])
+                    .status();
+                eprintln!("  Service restarting (launchd will respawn).\n");
+                Ok(())
+            }
+            _ => Err("Service is not installed. Run 'sudo numa service start' first.".to_string()),
+        }
+    }
+    #[cfg(target_os = "linux")]
+    {
+        run_systemctl(&["restart", "numa"])?;
+        eprintln!("  Service restarted.\n");
+        Ok(())
+    }
+    #[cfg(not(any(target_os = "macos", target_os = "linux")))]
+    {
+        Err("service restart not supported on this OS".to_string())
+    }
+}
+
 /// Show the service status.
 pub fn service_status() -> Result<(), String> {
     #[cfg(target_os = "macos")]