feat: add @bentoml.on_startup decorator

src/_bentoml_impl/server/app.py

@@ -278,6 +278,19 @@ async def create_instance(self, app: Starlette) -> None:
         self._service_instance = self.service()
         self.service.gradio_app_startup_hook(max_concurrency=self.max_concurrency)
         logger.info("Service %s initialized", self.service.name)
+
+        # Call on_startup hook with optional ctx or context parameter
+        for name, member in vars(self.service.inner).items():
+            if callable(member) and getattr(member, "__bentoml_startup_hook__", False):
+                logger.info("Running startup hook: %s", name)
+                result = getattr(
+                    self._service_instance, name
+                )()  # call the bound method
+                if inspect.isawaitable(result):
+                    await result
+                    logger.info("Completed async startup hook: %s", name)
+                else:
+                    logger.info("Completed startup hook: %s", name)
         if deployment_url := os.getenv("BENTOCLOUD_DEPLOYMENT_URL"):
             proxy = RemoteProxy(
                 deployment_url, service=self.service, media_type="application/json"

src/_bentoml_sdk/decorators.py

@@ -27,6 +27,12 @@ def on_shutdown(func: F) -> F:
     return func
 
 
+def on_startup(func: F) -> F:
+    """Mark a method as a startup hook for the service."""
+    setattr(func, "__bentoml_startup_hook__", True)
+    return func
+
+
 def on_deployment(func: t.Callable[P, R] | staticmethod[P, R]) -> staticmethod[P, R]:
     inner = func.__func__ if isinstance(func, staticmethod) else func
     setattr(inner, "__bentoml_deployment_hook__", True)

src/bentoml/__init__.py

@@ -59,6 +59,7 @@
     "task": "_bentoml_sdk:task",
     "depends": "_bentoml_sdk:depends",
     "on_shutdown": "_bentoml_sdk:on_shutdown",
+    "on_startup": "_bentoml_sdk:on_startup",
     "on_deployment": "_bentoml_sdk:on_deployment",
     "asgi_app": "_bentoml_sdk:asgi_app",
     "mount_asgi_app": "_bentoml_sdk:mount_asgi_app",
@@ -159,6 +160,7 @@
     from _bentoml_sdk import mount_asgi_app
     from _bentoml_sdk import on_deployment
     from _bentoml_sdk import on_shutdown
+    from _bentoml_sdk import on_startup
     from _bentoml_sdk import runner_service
     from _bentoml_sdk import service
     from _bentoml_sdk import task
@@ -373,6 +375,7 @@ def __getattr__(name: str) -> Any:
     "task",
     "images",
     "on_shutdown",
+    "on_startup",
     "on_deployment",
     "depends",
     "IODescriptor",