以及如何[使用 `CORSMiddleware` 处理 CORS](../tutorial/cors.md){.internal-link target=_blank}。

本章学习如何使用其它中间件。

## 添加 ASGI 中间件

因为 **FastAPI** 基于 Starlette，且执行 <abbr title="Asynchronous Server Gateway Interface，异步服务器网关界面">ASGI</abbr> 规范，所以可以使用任意 ASGI 中间件。

中间件不必是专为 FastAPI 或 Starlette 定制的，只要遵循 ASGI 规范即可。

总之，ASGI 中间件是类，并把 ASGI 应用作为第一个参数。

因此，有些第三方 ASGI 中间件的文档推荐以如下方式使用中间件：

```Python

  optional int64 observedGeneration = 1;

  // DisruptedPods contains information about pods whose eviction was
  // processed by the API server eviction subresource handler but has not
  // yet been observed by the PodDisruptionBudget controller.
  // A pod will be in this map from the time when the API server processed the
  // eviction request to the time when the pod is seen by PDB controller

	s.RestartIAMSuite(c)
}

func (s *TestSuiteIAM) SetUpSuite(c *check) {
	// If etcd backend is specified and etcd server is not present, the test
	// is skipped.
	etcdServer := env.Get(EnvTestEtcdBackend, "")
	if s.withEtcdBackend && etcdServer == "" {
		c.Skip("Skipping etcd backend IAM test as no etcd server is configured.")
	}

	s.TestSuiteCommon.SetUpSuite(c)

	s.iamSetup(c)

	if s.withEtcdBackend {

            if (!result.isEmpty()) {
                delete(userDN, adminEnv);
            } else {
                logger.info("{} does not exist in LDAP server.", user.getName());
            }
        });

    }

    public void insert(final Role role) {
        if (!fessConfig.isLdapAdminEnabled()) {
            return;
        }

Dieses können Sie dann mit dem Befehl `serve` bereitstellen:

<div class="termy">

```console
// Verwenden Sie das Kommando „serve“ nachdem Sie „build-all“ ausgeführt haben.
$ python ./scripts/docs.py serve

Warning: this is a very simple server. For development, use mkdocs serve instead.
This is here only to preview a site with translations already built.

utilize a versão com `Annotated` se possível.

///

```Python hl_lines="13-14"
{!> ../../docs_src/dependencies/tutorial008c.py!}
```

////

Neste caso, o cliente irá ver uma resposta *HTTP 500 Internal Server Error* como deveria acontecer, já que não estamos levantando nenhuma `HTTPException` ou coisa parecida, mas o servidor **não terá nenhum log** ou qualquer outra indicação de qual foi o erro. 😱

     * hashes (meaning negotiated via NTLM HTTP Authentication) and the other does not they will not be equal. This is
     * technically not correct however the server 8 byte challenge would be required to compute and compare the password
     * hashes but that it not available with this method.
     */
    @Override
    public boolean equals ( Object obj ) {

	}

	if err := target.send(eventData); err != nil {
		return err
	}

	// Delete the event from store.
	return target.store.Del(key)
}

// Close - closes underneath connections to NSQD server.
func (target *NSQTarget) Close() (err error) {
	close(target.quitCh)
	if target.producer != nil {
		// this blocks until complete:
		target.producer.Stop()
	}
	return nil
}

                    so it's an error from the API developer. So, FastAPI will raise an
                    error and return a 500 error code (Internal Server Error).

                Read more about it in the
                [FastAPI docs for Response Model](https://fastapi.tiangolo.com/tutorial/response-model/).
                """
            ),

<font color="#4E9A06">INFO</font>:     Started reloader process [<font color="#34E2E2"><b>2265862</b></font>] using <font color="#34E2E2"><b>WatchFiles</b></font>
<font color="#4E9A06">INFO</font>:     Started server process [<font color="#06989A">2265873</font>]
<font color="#4E9A06">INFO</font>:     Waiting for application startup.
<font color="#4E9A06">INFO</font>:     Application startup complete.
```

</div>