## Use `CORSMiddleware`

You can configure it in your **FastAPI** application using the `CORSMiddleware`.

* Import `CORSMiddleware`.
* Create a list of allowed origins (as strings).
* Add it as a "middleware" to your **FastAPI** application.

You can also specify whether your backend allows:

* Credentials (Authorization headers, Cookies, etc).

```console
// Don't run this now, it's just an example 🤓
$ pip install "fastapi[standard]"
---> 100%
```

</div>

That will download a compressed file with the FastAPI code, normally from <a href="https://pypi.org/project/fastapi/" class="external-link" target="_blank">PyPI</a>.

It will also **download** files for other packages that FastAPI depends on.

DockerやKubernetesなどのコンテナを使用している場合は、次の章で詳しく説明します： [コンテナ内のFastAPI - Docker](docker.md){.internal-link target=_blank}

特に**Kubernetes**上で実行する場合は、おそらく**Gunicornを使用せず**、**コンテナごとに単一のUvicornプロセス**を実行することになりますが、それについてはこの章の後半で説明します。

///

## GunicornによるUvicornのワーカー・プロセスの管理

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient


@pytest.fixture(name="client")
def get_client():
    from docs_src.body_multiple_params.tutorial003 import app

    client = TestClient(app)
    return client


def test_post_body_valid(client: TestClient):
    response = client.put(
        "/items/5",
        json={
            "importance": 2,

/// 정보

`OAuth2PasswordRequestForm`은 `OAuth2PasswordBearer`와 같이 **FastAPI**에 대한 특수 클래스가 아닙니다.

`OAuth2PasswordBearer`는 **FastAPI**가 보안 체계임을 알도록 합니다. 그래서 OpenAPI에 그렇게 추가됩니다.

그러나 `OAuth2PasswordRequestForm`은 직접 작성하거나 `Form` 매개변수를 직접 선언할 수 있는 클래스 의존성일 뿐입니다.

그러나 일반적인 사용 사례이므로 더 쉽게 하기 위해 **FastAPI**에서 직접 제공합니다.

///

### 폼 데이터 사용하기

/// 팁

///

```Python hl_lines="9"
{!> ../../docs_src/header_params/tutorial001.py!}
```

////

/// note | "技术细节"

`Header` 是 `Path`、`Query`、`Cookie` 的**兄弟类**，都继承自共用的 `Param` 类。

注意，从 `fastapi` 导入的 `Query`、`Path`、`Header` 等对象，实际上是返回特殊类的函数。

///

/// info | "说明"

必须使用 `Header` 声明 header 参数，否则该参数会被解释为查询参数。

///

## 自动转换

`Header` 比 `Path`、`Query` 和 `Cookie` 提供了更多功能。

# Deployment

Das Deployment einer **FastAPI**-Anwendung ist relativ einfach.

## Was bedeutet Deployment?

**Deployment** (Deutsch etwa: **Bereitstellen der Anwendung**) bedeutet, die notwendigen Schritte durchzuführen, um die Anwendung **für die Endbenutzer verfügbar** zu machen.

from fastapi.testclient import TestClient

from docs_src.path_params.tutorial004 import app

client = TestClient(app)


def test_file_path():
    response = client.get("/files/home/johndoe/myfile.txt")
    print(response.content)
    assert response.status_code == 200, response.text
    assert response.json() == {"file_path": "home/johndoe/myfile.txt"}


def test_root_file_path():
    response = client.get("/files//home/johndoe/myfile.txt")

import pytest
from fastapi.testclient import TestClient

from ...utils import needs_py39


@pytest.fixture(name="client")
def get_client():
    from docs_src.query_params_str_validations.tutorial013_an_py39 import app

    client = TestClient(app)
    return client


@needs_py39
def test_multi_query_values(client: TestClient):
    url = "/items/?q=foo&q=bar"
    response = client.get(url)

In unserem obigen Codebeispiel verwenden wir ihn nicht direkt, sondern übergeben ihn an FastAPI, damit es ihn verwenden kann.

Der Parameter `lifespan` der `FastAPI`-App benötigt einen **asynchronen Kontextmanager**, wir können ihm also unseren neuen asynchronen Kontextmanager `lifespan` übergeben.

```Python hl_lines="22"