feat: make frontend heartbeat extensible and lifecycle-safe (#8726)

* feat: make frontend heartbeat extensible and lifecycle-safe

Signed-off-by: jeremyhi <fengjiachun@gmail.com>

* fix: isolate heartbeat extension response handlers

Signed-off-by: jeremyhi <fengjiachun@gmail.com>

* fix: cancel in-flight heartbeat response handling

Signed-off-by: jeremyhi <fengjiachun@gmail.com>

* test: cover heartbeat wire compatibility

Signed-off-by: jeremyhi <fengjiachun@gmail.com>

* fix: clean up failed heartbeat startup

Signed-off-by: jeremyhi <fengjiachun@gmail.com>

* fix: address frontend heartbeat review feedback

Signed-off-by: jeremyhi <fengjiachun@gmail.com>

---------

Signed-off-by: jeremyhi <fengjiachun@gmail.com>
(cherry picked from commit 6ffa27bc8e78b5e11b2db3d2a898438446b298be)

src/plugins/src/frontend.rs

@@ -12,11 +12,14 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::sync::Arc;
+
 use auth::{DefaultPermissionChecker, PermissionCheckerRef, UserProviderRef};
 use common_base::Plugins;
 use common_meta::cache::CacheRegistryBuilder;
 use frontend::error::{IllegalAuthConfigSnafu, Result};
 use frontend::frontend::FrontendOptions;
+use frontend::heartbeat::FrontendHeartbeatExtensions;
 use frontend::instance::Instance;
 use frontend::instance::builder::FrontendBuilder;
 use snafu::ResultExt;
@@ -64,6 +67,20 @@ pub async fn setup_frontend_plugins_post_build(
     Ok(())
 }
 
+/// Sets up heartbeat extensions after the frontend [`Instance`] is available.
+///
+/// Implementations may use the instance to construct extensions and register them in the
+/// [`FrontendHeartbeatExtensions`] stored in `plugins`. Registrations must be idempotent because
+/// plugin setup can be invoked more than once.
+pub async fn setup_frontend_heartbeat_extensions(
+    plugins: &mut Plugins,
+    _plugin_options: &[PluginOptions],
+    _instance: &Arc<Instance>,
+) -> Result<()> {
+    plugins.get_or_insert(FrontendHeartbeatExtensions::default);
+    Ok(())
+}
+
 pub async fn start_frontend_plugins(_instance: &Instance) -> Result<()> {
     Ok(())
 }

src/plugins/src/lib.rs

@@ -28,7 +28,8 @@ pub use flownode::{
     setup_flownode_plugins_post_build, setup_flownode_plugins_pre_build, start_flownode_plugins,
 };
 pub use frontend::{
-    setup_frontend_plugins_post_build, setup_frontend_plugins_pre_build, start_frontend_plugins,
+    setup_frontend_heartbeat_extensions, setup_frontend_plugins_post_build,
+    setup_frontend_plugins_pre_build, start_frontend_plugins,
 };
 pub use meta_srv::{
     setup_metasrv_plugins_post_build, setup_metasrv_plugins_pre_build, start_metasrv_plugins,