if (writerTask != null) {
      taskQueue.schedule(writerTask)
    }
  }

  /**
   * Attempts to remove a single frame from a queue and send it. This prefers to write urgent pongs
   * before less urgent messages and close frames. For example it's possible that a caller will
   * enqueue messages followed by pongs, but this sends pongs followed by messages. Pongs are always
   * written in the order they were enqueued.

    - [Contextual Logging in Alpha](#contextual-logging-in-alpha)
    - [Avoiding Collisions in IP allocation to Services](#avoiding-collisions-in-ip-allocation-to-services)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
  - [Changes by Kind](#changes-by-kind-17)
    - [Deprecation](#deprecation)

  - [Known Issues](#known-issues)
    - [LocalStorageCapacityIsolationFSQuotaMonitoring ConfigMap rendering failure](#localstoragecapacityisolationfsquotamonitoring-configmap-rendering-failure)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
  - [Changes by Kind](#changes-by-kind-15)
    - [Deprecation](#deprecation)

    - [Server Binaries](#server-binaries-9)
    - [Node Binaries](#node-binaries-9)
    - [Container Images](#container-images-9)
  - [Changelog since v1.27.0](#changelog-since-v1270)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
  - [Changes by Kind](#changes-by-kind-9)
    - [Deprecation](#deprecation)

    - [Server Binaries](#server-binaries-4)
    - [Node Binaries](#node-binaries-4)
    - [Container Images](#container-images-4)
  - [Changelog since v1.28.0](#changelog-since-v1280)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
  - [Changes by Kind](#changes-by-kind-4)
    - [Deprecation](#deprecation)

  - [Known Issues](#known-issues)
    - [The PreEnqueue extension point doesn't work for Pods going to activeQ through backoffQ](#the-preenqueue-extension-point-doesnt-work-for-pods-going-to-activeq-through-backoffq)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
  - [Changes by Kind](#changes-by-kind-13)
    - [Deprecation](#deprecation)

    - [Server Binaries](#server-binaries-15)
    - [Node Binaries](#node-binaries-15)
    - [Container Images](#container-images-15)
  - [Changelog since v1.25.0](#changelog-since-v1250)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
  - [Changes by Kind](#changes-by-kind-15)
    - [Deprecation](#deprecation)

# Istio Agent

This document describes the internal architecture of Istio agent.

## High Level overview

![High Level overview](docs/overview.svg)

At a high level, the Istio agent acts as an intermediate proxy between Istiod and Envoy. This is done
at two levels. For distributing workload certificates, Envoy will send [SDS](https://www.envoyproxy.io/docs/envoy/latest/configuration/security/secret)

    ```Python hl_lines="5  12-16"
    {!> ../../../docs_src/security/tutorial002.py!}
    ```

## Eine `get_current_user`-Abhängigkeit erstellen

Erstellen wir eine Abhängigkeit `get_current_user`.

Erinnern Sie sich, dass Abhängigkeiten Unterabhängigkeiten haben können?

`get_current_user` wird seinerseits von `oauth2_scheme` abhängen, das wir zuvor erstellt haben.

```Python hl_lines="5  12-16"
{!../../../docs_src/security/tutorial002.py!}
```

## 依存関係 `get_current_user` を作成

依存関係 `get_current_user` を作ってみましょう。

依存関係はサブ依存関係を持つことができるのを覚えていますか？

`get_current_user` は前に作成した `oauth2_scheme` と同じ依存関係を持ちます。

以前直接 *path operation* の中でしていたのと同じように、新しい依存関係である `get_current_user` は `str` として `token` を受け取るようになります:

```Python hl_lines="25"
{!../../../docs_src/security/tutorial002.py!}
```