**FastAPI** 只执行主应用中的事件处理器，不执行[子应用 - 挂载](sub-applications.md){.internal-link target=_blank}中的事件处理器。

///

## `startup` 事件

使用 `startup` 事件声明 `app` 启动前运行的函数：

```Python hl_lines="8"
{!../../docs_src/events/tutorial001.py!}
```

本例中，`startup` 事件处理器函数为项目数据库（只是**字典**）提供了一些初始值。

**FastAPI** 支持多个事件处理器函数。

只有所有 `startup` 事件处理器运行完毕，**FastAPI** 应用才开始接收请求。

## `shutdown` 事件

使用 `shutdown` 事件声明 `app` 关闭时运行的函数：

# Testing Events: startup - shutdown

When you need your event handlers (`startup` and `shutdown`) to run in your tests, you can use the `TestClient` with a `with` statement:

```Python hl_lines="9-12  20-24"
{!../../docs_src/app_testing/tutorial003.py!}

        }
      };

  /** Constructor for use by subclasses. */
  protected AbstractExecutionThreadService() {}

  /**
   * Start the service. This method is invoked on the execution thread.
   *
   * <p>By default this method does nothing.
   */
  protected void startUp() throws Exception {}

  /**
   * Run the service. This method is invoked on the execution thread. Implementations must respond

    def main() -> Dict[str, str]:
        return {"message": "Hello World"}

    @app.on_event("startup")
    def app_startup() -> None:
        state.app_startup = True

    @app.on_event("shutdown")
    def app_shutdown() -> None:
        state.app_shutdown = True

    router = APIRouter()

    @router.on_event("startup")
    def router_startup() -> None:
        state.router_startup = True

 * Base class for services that can implement {@link #startUp} and {@link #shutDown} but while in
 * the "running" state need to perform a periodic task. Subclasses can implement {@link #startUp},
 * {@link #shutDown} and also a {@link #runOneIteration} method that will be executed periodically.
 *
 * <p>This class uses the {@link ScheduledExecutorService} returned from {@link #executor} to run

### Run Automatically on Startup

In general, you will probably want the server program (e.g. Uvicorn) to be started automatically on server startup, and without needing any **human intervention**, to have a process always running with your API (e.g. Uvicorn running your FastAPI app).

### Separate Program

    final CountDownLatch started = new CountDownLatch(1);
    FakeService service =
        new FakeService() {
          @Override
          protected void startUp() throws Exception {
            super.startUp();
            started.await();
          }
        };
    service.startAsync();
    service.stopAsync();
    started.countDown();
    service.awaitTerminated();

Ztunnel will use this to enter the Pod network namespace and start various listeners (inbound, outbound, etc).

> [!NOTE]
> While Ztunnel runs as a single shared binary on the node, each individual pod gets its own unique set of listeners within its own network namespace.

## Pod Startup

### Pod Startup Requirements

### BEGIN INIT INFO
# Provides:          fess
# Required-Start:    $network $remote_fs $named
# Required-Stop:     $network $remote_fs $named
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Starts fess
# Description:       Starts fess using start-stop-daemon
### END INIT INFO

PATH=/bin:/usr/bin:/sbin:/usr/sbin
NAME=fess
DESC="Fess Server"
DEFAULT=/etc/default/$NAME

if [ `id -u` -ne 0 ]; then

👫 🔢 💪 📣 ⏮️ `async def` ⚖️ 😐 `def`.

### `startup` 🎉

🚮 🔢 👈 🔜 🏃 ⏭ 🈸 ▶️, 📣 ⚫️ ⏮️ 🎉 `"startup"`:

```Python hl_lines="8"
{!../../docs_src/events/tutorial001.py!}
```

👉 💼, `startup` 🎉 🐕‍🦺 🔢 🔜 🔢 🏬 "💽" ( `dict`) ⏮️ 💲.

👆 💪 🚮 🌅 🌘 1️⃣ 🎉 🐕‍🦺 🔢.

& 👆 🈸 🏆 🚫 ▶️ 📨 📨 ⏭ 🌐 `startup` 🎉 🐕‍🦺 ✔️ 🏁.

### `shutdown` 🎉