#serviceAnnotations:
      #    cloud.google.com/load-balancer-type: "internal"

      podAnnotations: {}
      type: LoadBalancer #change to NodePort, ClusterIP or LoadBalancer if need be

      ##############
      secretVolumes:
      - name: ingressgateway-certs
        secretName: istio-ingressgateway-certs
        mountPath: /etc/istio/ingressgateway-certs

  optional string apiVersion = 3;
}

// ExternalMetricSource indicates how to scale on a metric not associated with
// any Kubernetes object (for example length of queue in cloud
// messaging service, or QPS from loadbalancer running outside of cluster).
message ExternalMetricSource {
  // metric identifies the target metric by name and selector
  optional MetricIdentifier metric = 1;

  // target specifies the target value for the given metric

  optional string apiVersion = 3;
}

// ExternalMetricSource indicates how to scale on a metric not associated with
// any Kubernetes object (for example length of queue in cloud
// messaging service, or QPS from loadbalancer running outside of cluster).
// Exactly one "target" type should be set.
message ExternalMetricSource {
  // metricName is the name of the metric in question.
  optional string metricName = 1;

                format: int32
                type: integer
              nodeSelectors:
                description: NodeSelectors allows to limit the nodes to announce as
                  next hops for the LoadBalancer IP. When empty, all the nodes having  are
                  announced as next hops.
                items:
                  description: A label selector is a label query over a set of resources.

  optional string apiVersion = 3;
}

// ExternalMetricSource indicates how to scale on a metric not associated with
// any Kubernetes object (for example length of queue in cloud
// messaging service, or QPS from loadbalancer running outside of cluster).
message ExternalMetricSource {
  // metric identifies the target metric by name and selector
  optional MetricIdentifier metric = 1;

  // target specifies the target value for the given metric

    port: {{ $val.Port }}
    protocol: TCP
    appProtocol: {{ $val.AppProtocol }}
  {{- end }}
  selector:
    "{{.GatewayNameLabel}}": "{{.Name}}"
  {{- if and (.Spec.Addresses) (eq .ServiceType "LoadBalancer") }}
  loadBalancerIP: {{ (index .Spec.Addresses 0).Value | quote}}
  {{- end }}
  type: {{ .ServiceType | quote }}

}} {{- end }} {{- if or (eq .Values.service.type "LoadBalancer") (eq .Values.service.type "NodePort") }} externalTrafficPolic: {{ .Values.service.externalTrafficPolic | quote }} {{- end }} {{- if and (eq .Values.service.type "LoadBalancer") .Values.service.loadBalancerSourceRa }} loadBalancerSourceRa: {{ .Values.service.loadBalancerSourceRa }} {{ end }} {{- if and (eq .Values.service.type "LoadBalancer") (not (empty .Values.service.loadBalancerIP)) }} loadBalancerIP: {{ default "" .Values.service.loadBalancerIP...

      service = "app"
      rule = "PathPrefix(`/api/v1`)"
      middlewares = ["api-stripprefix"]

  [http.services]

    [http.services.app]
      [http.services.app.loadBalancer]
        [[http.services.app.loadBalancer.servers]]
          url = "http://127.0.0.1:8000"
```

这个文件配置 Traefik 使用路径前缀 `/api/v1`。

然后，它把请求重定位到运行在 `http://127.0.0.1:8000` 上的 Uvicorn。

现在，启动 Traefik：

  optional string apiVersion = 3;
}

// ExternalMetricSource indicates how to scale on a metric not associated with
// any Kubernetes object (for example length of queue in cloud
// messaging service, or QPS from loadbalancer running outside of cluster).
message ExternalMetricSource {
  // metricName is the name of the metric in question.
  optional string metricName = 1;

  // metricSelector is used to identify a specific time series

      service = "app"
      rule = "PathPrefix(`/api/v1`)"
      middlewares = ["api-stripprefix"]

  [http.services]

    [http.services.app]
      [http.services.app.loadBalancer]
        [[http.services.app.loadBalancer.servers]]
          url = "http://127.0.0.1:8000"
```

This file configures Traefik to use the path prefix `/api/v1`.