Я розповім більше про образи контейнерів, Docker, Kubernetes тощо в майбутньому розділі: [FastAPI у контейнерах - Docker](docker.md).

///

## Попередні кроки перед стартом { #previous-steps-before-starting }

Є багато випадків, коли потрібно виконати деякі кроки **перед стартом** вашого застосунку.

Наприклад, ви можете захотіти запустити **міграції бази даних**.

若你需要在 Pydantic v1 模型上使用 FastAPI 的參數工具（例如 `Body`、`Query`、`Form` 等），在完成遷移到 Pydantic v2 之前，可以從 `fastapi.temp_pydantic_v1_params` 匯入：

{* ../../docs_src/pydantic_v1_in_v2/tutorial004_an_py310.py hl[4,18] *}

### 分步遷移 { #migrate-in-steps }

/// tip

先嘗試使用 `bump-pydantic`，如果測試通過且一切正常，你就能用一條指令完成遷移。✨

///

若 `bump-pydantic` 不適用於你的情境，可以利用在同一應用同時支援 Pydantic v1 與 v2 的能力，逐步完成遷移。

你可以先升級 Pydantic 到最新 v2，並將所有模型的匯入改為使用 `pydantic.v1`。

labels: [question]
body:
  - type: markdown
    attributes:
      value: |
        Thanks for your interest in FastAPI! 🚀

        Please follow these instructions, fill every question, and do every step. 🙏

        I'm asking this because answering questions and solving problems in GitHub is what consumes most of the time.

* Security - HTTPS
* Running on startup
* Restarts
* Replication (the number of processes running)
* Memory
* Previous steps before starting

 * an existing external tool is required.
 *
 * See https://stackoverflow.com/questions/61929216/how-to-log-tlsv1-3-keys-in-jsse-for-wireshark-to-decode-traffic
 *
 * Steps to run in your own code
 *
 * 1. In your main method `WireSharkListenerFactory.register()`
 * 2. Create Listener factory `val eventListenerFactory = WireSharkListenerFactory(

따라서, 아래는 모두 상이한 출처입니다:

* `http://localhost`
* `https://localhost`
* `http://localhost:8080`

모두 `localhost`에 있더라도, 서로 다른 프로토콜이나 포트를 사용하므로 서로 다른 "출처"입니다.

## 단계 { #steps }

그러면 브라우저에서 `http://localhost:8080`으로 실행되는 프론트엔드가 있고, 그 JavaScript가 `http://localhost`에서 실행되는 백엔드와 통신하려고 한다고 해봅시다(포트를 명시하지 않았기 때문에, 브라우저는 기본 포트 `80`을 가정합니다).

  }

  public void testPeekingIteratorBehavesLikeIteratorOnSingletonIterable() {
    actsLikeIteratorHelper(singletonList(new Object()));
  }

  // TODO(cpovirk): instead of skipping, use a smaller number of steps
  @GwtIncompatible // works but takes 5 minutes to run
  public void testPeekingIteratorBehavesLikeIteratorOnThreeElementIterable() {
    actsLikeIteratorHelper(Lists.newArrayList("A", "B", "C"));
  }

 4. If it's a new route, it connects by building either a direct socket connection, a TLS tunnel (for HTTPS over an HTTP proxy), or a direct TLS connection. It does TLS handshakes as necessary. This step may be retried for tunnel challenges and TLS handshake failures.
 5. It sends the HTTP request and reads the response.

### 1. Fetch the root identity

As the initial step, fetch the private key and certificate of the root identity:

```sh
curl -sSL --tlsv1.2 \
     -O 'https://raw.githubusercontent.com/minio/kes/master/root.key' \

We’ve included deprecated APIs in OkHttp 4.0 because they make migration easy. We will remove them
in a future release! If you’re skipping releases, it’ll be much easier if you upgrade to OkHttp 4.0
as an intermediate step.

#### Vars and Vals

Java doesn’t have language support for properties so developers make do with getters and setters.
Kotlin does have properties and we take advantage of them in OkHttp.