// +optional
  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;

  // API version of the referent
  // +optional
  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.

{{- end }}
  volumes:
  - emptyDir:
    name: workload-socket
  {{- if eq .Values.global.caName "GkeWorkloadCertificate" }}
  - name: gke-workload-certificate
    csi:
      driver: workloadcertificates.security.cloud.google.com
  {{- else }}
  - emptyDir:
    name: workload-certs
  {{- end }}
  {{- if (isset .ObjectMeta.Annotations `sidecar.istio.io/bootstrapOverride`) }}
  - name: custom-bootstrap-volume
    configMap:

      - emptyDir: {}
        name: credential-socket
      {{- if eq .Values.global.caName "GkeWorkloadCertificate" }}
      - name: gke-workload-certificate
        csi:
          driver: workloadcertificates.security.cloud.google.com
      {{- else}}
      - emptyDir: {}
        name: workload-certs
      {{- end }}
      # SDS channel between istioagent and Envoy
      - emptyDir:
          medium: Memory

the project's [log viewer](https://cloud.google.com/logging/docs/view/overview) and/or the `gcloud logging read`
capability.

The following example grabs the last 10 `kubelet` logs containing the string "cmdAdd" in the log message.

```console

  // The format of the error shall comply with the following rules:
  // - built-in error values shall be specified in this file and those shall use
  //   CamelCase names
  // - cloud provider specific error values must have names that comply with the
  //   format foo.example.com/CamelCase.
  // ---
  // The regex it matches is (dns1123SubdomainFmt/)?(qualifiedNameFmt)
  // +optional

  // The format of the error shall comply with the following rules:
  // - built-in error values shall be specified in this file and those shall use
  //   CamelCase names
  // - cloud provider specific error values must have names that comply with the
  //   format foo.example.com/CamelCase.
  // ---
  // The regex it matches is (dns1123SubdomainFmt/)?(qualifiedNameFmt)
  // +optional

  - emptyDir:
    name: credential-socket
  {{- if eq .Values.global.caName "GkeWorkloadCertificate" }}
  - name: gke-workload-certificate
    csi:
      driver: workloadcertificates.security.cloud.google.com
  {{- else }}
  - emptyDir:
    name: workload-certs
  {{- end }}
  {{- if (isset .ObjectMeta.Annotations `sidecar.istio.io/bootstrapOverride`) }}
  - name: custom-bootstrap-volume
    configMap:

  - emptyDir:
    name: credential-socket
  {{- if eq .Values.global.caName "GkeWorkloadCertificate" }}
  - name: gke-workload-certificate
    csi:
      driver: workloadcertificates.security.cloud.google.com
  {{- else }}
  - emptyDir:
    name: workload-certs
  {{- end }}
  {{- if (isset .ObjectMeta.Annotations `sidecar.istio.io/bootstrapOverride`) }}
  - name: custom-bootstrap-volume
    configMap:

      ipFamilyPolicy: ""
      ipFamilies: []

      # To generate an internal load balancer:
      # --set serviceAnnotations.cloud.google.com/load-balancer-type=internal
      #serviceAnnotations:
      #    cloud.google.com/load-balancer-type: "internal"

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

      ##############