我们将在主 `FastAPI` 应用中包含该 `APIRouter`，但首先，让我们来看看依赖项和另一个 `APIRouter`。

## 依赖项

我们了解到我们将需要一些在应用程序的好几个地方所使用的依赖项。

因此，我们将它们放在它们自己的 `dependencies` 模块（`app/dependencies.py`）中。

现在我们将使用一个简单的依赖项来读取一个自定义的 `X-Token` 请求首部：

```Python hl_lines="1  4-6" title="app/dependencies.py"
{!../../docs_src/bigger_applications/app/dependencies.py!}
```

/// tip

我们正在使用虚构的请求首部来简化此示例。

pkg go/build, type Directive struct #56986
pkg go/build, type Directive struct, Pos token.Position #56986
pkg go/build, type Directive struct, Text string #56986
pkg go/build, type Package struct, Directives []Directive #56986
pkg go/build, type Package struct, TestDirectives []Directive #56986
pkg go/build, type Package struct, XTestDirectives []Directive #56986
pkg go/token, method (*File) Lines() []int #57708

 *
 * <p>A high-quality hash function strives for some subset of the following virtues:
 *
 * <ul>
 *   <li><b>collision-resistant:</b> while the definition above requires making at least <i>some</i>
 *       token attempt, one measure of the quality of a hash function is <i>how well</i> it succeeds
 *       at this goal. Important note: it may be easy to achieve the theoretical minimum collision

 *
 * <p>A high-quality hash function strives for some subset of the following virtues:
 *
 * <ul>
 *   <li><b>collision-resistant:</b> while the definition above requires making at least <i>some</i>
 *       token attempt, one measure of the quality of a hash function is <i>how well</i> it succeeds
 *       at this goal. Important note: it may be easy to achieve the theoretical minimum collision

def get_graphql_response(
    *,
    settings: Settings,
    query: str,
    after: Union[str, None] = None,
    category_id: Union[str, None] = None,
) -> Dict[str, Any]:
    headers = {"Authorization": f"token {settings.input_token.get_secret_value()}"}
    # category_id is only used by one query, but GraphQL allows unused variables, so
    # keep it here for simplicity
    variables = {"after": after, "category_id": category_id}

pkg encoding/base32, method (Encoding) WithPadding(int32) *Encoding
pkg encoding/csv, type Reader struct, ReuseRecord bool
pkg encoding/json, func Valid([]uint8) bool
pkg go/ast, type TypeSpec struct, Assign token.Pos
pkg go/types, func SizesFor(string, string) Sizes
pkg go/types, method (*TypeName) IsAlias() bool
pkg hash/fnv, func New128() hash.Hash
pkg hash/fnv, func New128a() hash.Hash

					"initContainers": [
						"istio-init"
					],
					"containers": [
						"istio-proxy"
					],
					"volumes": [
						"istio-envoy",
						"istio-data",
						"istio-podinfo",
						"istio-token",
						"istiod-ca-cert"
					],
					"imagePullSecrets": null,
					"revision": "1-13-2"
				}`,
			},
			expected: "1-13-2",
		},
	}

	for _, tc := range cases {

  - This changes the tokens provided to containers at `/var/run/secrets/kubernetes.io/serviceaccount/token` to be time-limited, auto-refreshed, and invalidated when the containing pod is deleted.
  - Clients should reload the token from disk periodically (once per minute is recommended) to ensure they continue to use a valid token. `k8s.io/client-go` version v11.0.0+ and v0.15.0+ reload tokens automatically.

		return xml.UnmarshalError(fmt.Sprintf("expected element type <LegalHold>/<ObjectLockLegalHold> but have <%s>",
			start.Name.Local))
	}
	for {
		// Read tokens from the XML document in a stream.
		t, err := d.Token()
		if err != nil {
			if err == io.EOF {
				break
			}
			return err
		}

		if se, ok := t.(xml.StartElement); ok {
			switch se.Name.Local {
			case "Status":
				var st LegalHoldStatus

  * All communication is now over TLS
  * Authorization plugins can be installed by kubeadm, including the new default of RBAC
  * The bootstrap token system now allows token management and expiration
* The [`kubefed` federation bootstrap tool](https://kubernetes.io/docs/tutorials/federation/set-up-cluster-federation-kubefed/) has also graduated to beta.