/**
   * Invoked as soon as a call causes a connection to be started.
   */
  open fun connectStart(
    route: Route,
    call: Call,
  ) {}

  /**
   * Invoked when a connection fails to be established.
   */
  open fun connectFailed(
    route: Route,
    call: Call,
    failure: IOException,
  ) {}

  /**
   * Invoked as soon as a connection is successfully established.
   */

    dns.assertRequests(uriHost)
    val routes = selection.routes
    assertRoute(routes[0], address, Proxy.NO_PROXY, dns.lookup(uriHost, 0), uriPort)
    assertRoute(routes[1], address, Proxy.NO_PROXY, dns.lookup(uriHost, 1), uriPort)
    assertThat(selection.next()).isSameInstanceAs(routes[0])
    assertThat(selection.next()).isSameInstanceAs(routes[1])
    assertThat(selection.hasNext()).isFalse()

    override val timestampNs: Long,
    val route: Route,
    val call: Call,
  ) : ConnectionEvent()

  data class ConnectFailed(
    override val timestampNs: Long,
    val route: Route,
    val call: Call,
    val exception: IOException,
  ) : ConnectionEvent() {
    override fun closes(event: ConnectionEvent): Boolean = event is ConnectStart && call == event.call && route == event.route
  }

  data class ConnectEnd(

* `summary`: A short summary of the API.
* `description`: The description of your API, this can include markdown and will be shown in the docs.
* `routes`: A list of routes, these are each of the registered *path operations*. They are taken from `app.routes`.

/// info

The parameter `summary` is available in OpenAPI 3.1.0 and above, supported by FastAPI 0.99.0 and above.

///

[entryPoints]
  [entryPoints.http]
    address = ":9999"

[providers]
  [providers.file]
    filename = "routes.toml"
```

これは Traefik にポート 9999 で待ち受け、別のファイル `routes.toml` を使用するよう指示します。

/// tip | 豆知識

標準の HTTP ポート 80 ではなく 9999 を使うのは、管理者（`sudo`）権限で実行する必要をなくすためです。

///

次に、その `routes.toml` ファイルを作成します:

```TOML hl_lines="5  12  20"
[http]
  [http.middlewares]

) : okhttp3.Authenticator {
  @Throws(IOException::class)
  override fun authenticate(
    route: Route?,
    response: Response,
  ): Request? {
    val challenges = response.challenges()
    val request = response.request
    val url = request.url
    val proxyAuthorization = response.code == 407
    val proxy = route?.proxy ?: Proxy.NO_PROXY

    for (challenge in challenges) {

    }
  }

  override fun connectStart(
    route: Route,
    call: Call,
  ) = logEvent(ConnectionEvent.ConnectStart(System.nanoTime(), route, call))

  override fun connectFailed(
    route: Route,
    call: Call,
    failure: IOException,
  ) = logEvent(
    ConnectionEvent.ConnectFailed(System.nanoTime(), route, call, failure),
  )

  override fun connectEnd(

class JavaNetAuthenticator : Authenticator {
  @Throws(IOException::class)
  override fun authenticate(
    route: Route?,
    response: Response,
  ): Request? = JAVA_NET_AUTHENTICATOR.authenticate(route, response)

   *
   * The route is best effort, it currently may not always be provided even when logically
   * available. It may also not be provided when an authenticator is re-used manually in an
   * application interceptor, such as when implementing client-specific retries.
   */
  @Throws(IOException::class)
  fun authenticate(
    route: Route?,
    response: Response,
  ): Request?

  val failedRoutes: Set<Route>
    @Synchronized get() = _failedRoutes.toSet()

  /** Records a failure connecting to [failedRoute]. */
  @Synchronized fun failed(failedRoute: Route) {
    _failedRoutes.add(failedRoute)
  }

  /** Records success connecting to [route]. */
  @Synchronized fun connected(route: Route) {
    _failedRoutes.remove(route)
  }