Te contaré más sobre imágenes de contenedores, Docker, Kubernetes, etc. en un capítulo futuro: [FastAPI en Contenedores - Docker](docker.md){.internal-link target=_blank}.

///

## Pasos Previos Antes de Iniciar { #previous-steps-before-starting }

Hay muchos casos en los que quieres realizar algunos pasos **antes de iniciar** tu aplicación.

Por ejemplo, podrías querer ejecutar **migraciones de base de datos**.

    };
  }

  /**
   * Shuts down the given executor service gradually, first disabling new submissions and later, if
   * necessary, cancelling remaining tasks.
   *
   * <p>The method takes the following steps:
   *
   * <ol>
   *   <li>calls {@link ExecutorService#shutdown()}, disabling acceptance of new submitted tasks.
   *   <li>awaits executor service termination for half of the specified timeout.

The TensorFlow project strives to abide by generally accepted best practices in
open-source software development.

## Patching guidelines

Follow these steps to patch a specific version of TensorFlow, for example, to
apply fixes to bugs or security vulnerabilities:

*   Clone the TensorFlow repository and switch to the appropriate branch for

 with its <<<DefaultModelBuilder>>> implementation
 ({{{./apidocs/org/apache/maven/model/building/DefaultModelBuilder.html}javadoc}},
 {{{./xref/org/apache/maven/model/building/DefaultModelBuilder.html}source}})
 that manages the steps sequence.

 The sequence is divided into 2 phases:

 * phase 1

   ** profile activation: see {{{./apidocs/org/apache/maven/model/profile/activation/package-summary.html}available activators}}.

* Aplicar regras de segurança, autenticação, papéis de usuários, etc.
* E muitas outras coisas...

Tudo isso, enquanto minimizamos a repetição de código.

## Primeiros passos { #first-steps }

Vamos ver um exemplo simples. Tão simples que não será muito útil, por enquanto.

Mas dessa forma podemos focar em como o sistema de **Injeção de Dependência** funciona.

* 📝 Update `security/first-steps.md`. PR [#11674](https://github.com/tiangolo/fastapi/pull/11674) by [@alejsdev](https://github.com/alejsdev).
* 📝 Update `security/first-steps.md`. PR [#11673](https://github.com/tiangolo/fastapi/pull/11673) by [@alejsdev](https://github.com/alejsdev).

* Compartir conexiones a bases de datos.
* Imponer seguridad, autenticación, requisitos de roles, etc.
* Y muchas otras cosas...

Todo esto, mientras minimizas la repetición de código.

## Primeros Pasos { #first-steps }

Veamos un ejemplo muy simple. Será tan simple que no es muy útil, por ahora.

Pero de esta manera podemos enfocarnos en cómo funciona el sistema de **Inyección de Dependencias**.

{* ../../docs_src/security/tutorial005_an_py310.py hl[5,9,13,47,65,106,108:116,122:126,130:136,141,157] *}

Now let's review those changes step by step.

## OAuth2 Security scheme { #oauth2-security-scheme }

The first change is that now we are declaring the OAuth2 security scheme with two available scopes, `me` and `items`.

The steps below show how to use this notification target in `namespace` format. The other format is very similar and is omitted for brevity.

### Step 1: Ensure Elasticsearch minimum requirements are met

    assertEquals(68, (int) mmHeap.peek());
    assertEquals(0, (int) mmHeap.peekLast());
  }

  private <T extends Comparable<T>> void runIterator(List<T> values, int steps) throws Exception {
    IteratorTester<T> tester =
        new IteratorTester<T>(
            steps,
            IteratorFeature.MODIFIABLE,
            new LinkedList<>(values),
            IteratorTester.KnownOrder.UNKNOWN_ORDER) {