chore: expose some methods (#5784)

src/cmd/src/frontend.rs

@@ -61,6 +61,14 @@ impl Instance {
     pub fn new(frontend: Frontend, _guard: Vec<WorkerGuard>) -> Self {
         Self { frontend, _guard }
     }
+
+    pub fn inner(&self) -> &Frontend {
+        &self.frontend
+    }
+
+    pub fn mut_inner(&mut self) -> &mut Frontend {
+        &mut self.frontend
+    }
 }
 
 #[async_trait]

src/cmd/src/standalone.rs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::net::SocketAddr;
 use std::sync::Arc;
 use std::{fs, path};
 
@@ -254,6 +255,13 @@ pub struct Instance {
     _guard: Vec<WorkerGuard>,
 }
 
+impl Instance {
+    /// Find the socket addr of a server by its `name`.
+    pub async fn server_addr(&self, name: &str) -> Option<SocketAddr> {
+        self.frontend.server_handlers().addr(name).await
+    }
+}
+
 #[async_trait]
 impl App for Instance {
     fn name(&self) -> &str {

src/frontend/src/frontend.rs

@@ -131,6 +131,10 @@ impl Frontend {
             .await
             .context(error::ShutdownServerSnafu)
     }
+
+    pub fn server_handlers(&self) -> &ServerHandlers {
+        &self.servers
+    }
 }
 
 #[cfg(test)]