responses_from_routes.append(route.response_field)
            if route.response_fields:
                responses_from_routes.extend(route.response_fields.values())
            if route.callbacks:
                callback_flat_models.extend(get_fields_from_routes(route.callbacks))
            params = get_flat_params(route.dependant)
            request_fields_from_routes.extend(params)

  /** Returns a plan for the first attempt at [route]. This throws if no plan is possible. */
  @Throws(IOException::class)
  internal fun planConnectToRoute(
    route: Route,
    routes: List<Route>? = null,
  ): ConnectPlan {
    if (route.address.sslSocketFactory == null) {
      if (ConnectionSpec.CLEARTEXT !in route.address.connectionSpecs) {
        throw UnknownServiceException("CLEARTEXT communication not enabled for client")

    http2Connection.start()
  }

  /**
   * Returns true if this connection can carry a stream allocation to `address`. If non-null
   * `route` is the resolved route for a connection.
   */
  internal fun isEligible(
    address: Address,
    routes: List<Route>?,
  ): Boolean {
    lock.assertHeld()

    // If this connection is not accepting new exchanges, we're done.

  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)
  }

{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

!!! tip
    Notice that you are not passing the router itself (`invoices_callback_router`) to `callback=`, but the attribute `.routes`, as in `invoices_callback_router.routes`.

### Check the docs

Now you can start your app with Uvicorn and go to <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

      pingIntervalMillis = pingIntervalMillis,
      retryOnConnectionFailure = retryOnConnectionFailure,
      user = user,
      routePlanner = routePlanner,
      route = route,
      routes = routes,
      attempt = attempt,
      tunnelRequest = tunnelRequest,
      connectionSpecIndex = connectionSpecIndex,
      isTlsFallback = isTlsFallback,
    )
  }

   *
   * If [routes] is non-null these are the resolved routes (ie. IP addresses) for the connection.
   * This is used to coalesce related domains to the same HTTP/2 connection, such as `square.com`
   * and `square.ca`.
   */
  fun callAcquirePooledConnection(
    doExtensiveHealthChecks: Boolean,
    address: Address,
    connectionUser: ConnectionUser,
    routes: List<Route>?,

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

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

这个文件把 Traefik 监听端口设置为 `9999`，并设置要使用另一个文件 `routes.toml`。

!!! tip "提示"

    使用端口 9999 代替标准的 HTTP 端口 80，这样就不必使用管理员权限运行（`sudo`）。

接下来，创建 `routes.toml`：

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

    [http.middlewares.api-stripprefix.stripPrefix]

    address = ":9999"

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

This tells Traefik to listen on port 9999 and to use another file `routes.toml`.

!!! tip
    We are using port 9999 instead of the standard HTTP port 80 so that you don't have to run it with admin (`sudo`) privileges.

Now create that other file `routes.toml`:

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

			expectedString:   "unrecognized logger name: xxx",
			wantException:    true,
		},
		{ // routes invalid
			args:           strings.Split("routes invalid", " "),
			expectedString: "unable to retrieve Pod: pods \"invalid\" not found",
			wantException:  true, // "istioctl proxy-config routes invalid" should fail
		},
		{ // bootstrap invalid
			args:           strings.Split("bootstrap invalid", " "),