<dependencies>
    <dependency>
      <groupId>maven-test</groupId>
      <artifactId>t07-d</artifactId>
      <version>1.1</version>
      <type>jar</type>
      <scope>compile</scope>
      <optional>true</optional>
    </dependency>
  </dependencies>

### 2. Run MinIO in federated mode

Bucket lookup from DNS federation requires two dependencies

- etcd (for bucket DNS service records)
- CoreDNS (for DNS management based on populated bucket DNS service records, optional)

## Architecture

![bucket-lookup](https://github.com/minio/minio/blob/master/docs/federation/lookup/bucket-lookup.png?raw=true)

### Environment variables

#### MINIO_ETCD_ENDPOINTS

    </dependency>
    <dependency>
      <groupId>maven-test</groupId>
      <artifactId>t08-d</artifactId>
      <version>1.1</version>
      <type>jar</type>
      <scope>compile</scope>
      <optional>false</optional>
    </dependency>
  </dependencies>

    </dependency>
    <dependency>
      <groupId>maven-test</groupId>
      <artifactId>t08-d</artifactId>
      <version>1.1</version>
      <type>jar</type>
      <scope>compile</scope>
      <optional>false</optional>
    </dependency>
  </dependencies>

* パラメータが **Pydantic モデル**型で宣言された場合、リクエスト**ボディ**として解釈されます。

!!! note "備考"
    FastAPIは、`= None`があるおかげで、`q`がオプショナルだとわかります。

    `Optional[str]` の`Optional` はFastAPIでは使用されていません（FastAPIは`str`の部分のみ使用します）。しかし、`Optional[str]` はエディタがコードのエラーを見つけるのを助けてくれます。

## Pydanticを使わない方法

    ) : Closeable by body

    internal companion object {
      /** These options follow the boundary. */
      val afterBoundaryOptions =
        Options.of(
          // 0.  "\r\n"  More parts.
          "\r\n".encodeUtf8(),
          // 1.  "--"    No more parts.
          "--".encodeUtf8(),
          // 2.  " "     Optional whitespace. Only used if there are more parts.
          " ".encodeUtf8(),

```

Ici, le paramètre `q` sera optionnel, et aura `None` comme valeur par défaut.

!!! check "Remarque"
    On peut voir que **FastAPI** est capable de détecter que le paramètre de chemin `item_id` est un paramètre de chemin et que `q` n'en est pas un, c'est donc un paramètre de requête.

!!! note
    **FastAPI** saura que `q` est optionnel grâce au `=None`.

    </dependency>
    <dependency>
      <groupId>maven-test</groupId>
      <artifactId>t05-d</artifactId>
      <version>1.1</version>
      <type>jar</type>
      <scope>compile</scope>
      <optional>false</optional>
    </dependency>
  </dependencies>

    ```

`OAuth2PasswordRequestForm` is a class dependency that declares a form body with:

* The `username`.
* The `password`.
* An optional `scope` field as a big string, composed of strings separated by spaces.
* An optional `grant_type`.

!!! tip
    The OAuth2 spec actually *requires* a field `grant_type` with a fixed value of `password`, but `OAuth2PasswordRequestForm` doesn't enforce it.

import org.gradle.api.provider.ValueSourceParameters
import org.gradle.api.tasks.Optional


abstract class BuildTimestampFromBuildReceiptValueSource : ValueSource<String, BuildTimestampFromBuildReceiptValueSource.Parameters>, Describable {

    interface Parameters : ValueSourceParameters {

        val ignoreIncomingBuildReceipt: Property<Boolean>

        @get:Optional
        val buildReceiptFileContents: Property<String>
    }