```

The following arguments are supported:

* `allowed_hosts` - A list of domain names that should be allowed as hostnames. Wildcard domains such as `*.example.com` are supported for matching subdomains. To allow any hostname either use `allowed_hosts=["*"]` or omit the middleware.

If an incoming request does not validate correctly then a `400` response will be sent.

## `GZipMiddleware`

Flask is a "microframework", it doesn't include database integrations nor many of the things that come by default in Django.

This simplicity and flexibility allow doing things like using NoSQL databases as the main data storage system.

As it is very simple, it's relatively intuitive to learn, although the documentation gets somewhat technical at some points.

Вполне вероятно, что вы увидите несколько процессов с одним и тем же названием браузерной программы (Firefox, Chrome, Edge и т. Д.). Обычно браузеры запускают один процесс на вкладку и вдобавок некоторые дополнительные процессы.

<img class="shadow" src="/img/deployment/concepts/image01.png">

---

Теперь, когда нам известна разница между **процессом** и **программой**, давайте продолжим обсуждение развёртывания.

## Настройки запуска приложения

OSの「タスク・マネージャー」や「システム・モニター」（または同様のツール）を確認すれば、これらのプロセスの多くが実行されているの見ることができるでしょう。

例えば、同じブラウザプログラム（Firefox、Chrome、Edgeなど）を実行しているプロセスが複数あることがわかります。通常、1つのタブにつき1つのプロセスが実行され、さらに他のプロセスも実行されます。

<img class="shadow" src="/img/deployment/concepts/image01.png">

---

さて、**プロセス**と**プログラム**という用語の違いを確認したところで、デプロイメントについて話を続けます。

## 起動時の実行

    */
  content: "\00A0[↪]";
}

a.internal-link::after {
  /* \00A0 is a non-breaking space
        to make the mark be on the same line as the link
    */
  content: "\00A0↪";
}

.shadow {
  box-shadow: 5px 5px 10px #999;
}

/* Give space to lower icons so Gitter chat doesn't get on top of them */
.md-footer-meta {
  padding-bottom: 2em;
}

.user-list {
  display: flex;
  flex-wrap: wrap;

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

    github_sponsors_old_content = github_sponsors_path.read_text(encoding="utf-8")
    new_people_content = yaml.dump(
        people, sort_keys=False, width=200, allow_unicode=True
    )
    new_github_sponsors_content = yaml.dump(
        github_sponsors, sort_keys=False, width=200, allow_unicode=True
    )
    if (
        people_old_content == new_people_content
        and github_sponsors_old_content == new_github_sponsors_content

### Fixes

* 🐛 Allow exit code for dependencies with `yield` to always execute, by removing capacity limiter for them, to e.g. allow closing DB connections without deadlocks. PR [#5122](https://github.com/tiangolo/fastapi/pull/5122) by [@adriangb](https://github.com/adriangb).

And, for example, you will probably see that there are multiple processes running the same browser program (Firefox, Chrome, Edge, etc). They normally run one process per tab, plus some other extra processes.

<img class="shadow" src="/img/deployment/concepts/image01.png">

---

Now that we know the difference between the terms **process** and **program**, let's continue talking about deployments.

## Running on Startup

Create a PassLib "context". This is what will be used to hash and verify passwords.

!!! tip
    The PassLib context also has functionality to use different hashing algorithms, including deprecated old ones only to allow verifying them, etc.

    For example, you could use it to read and verify passwords generated by another system (like Django) but hash any new passwords with a different algorithm like Bcrypt.