How to configure stats_sinks correctly

Hi guys, i am trying to configure “stats_sinks” so that envoy can send metrics to statsd_exporter which is already deployed in same pod with my service.

I’ve tried to customize envoy boostrap configuration according to this article(https://github.com/istio/istio/tree/master/samples/custom-bootstrap) to achieve this, but things not going right.

I applied below configmap first:

apiVersion: v1
kind: ConfigMap
metadata:
  name: istio-custom-bootstrap-config
  namespace: default
data:
  custom_bootstrap.json: |
    {
      "stats_sinks": [
        {
          "name": "envoy.stat_sinks.statsd",
          "typed_config": {
            "address": {
              "socket_address": {
                "address": "127.0.0.1",
                "port_value": "9125"
              }
            },
            "tcp_cluster_name": "statsd-exporter",
            "prefix": "productpage"
          }
        }
      ]
    }

And then add an annotation to deployment:

sidecar.istio.io/bootstrapOverride: istio-custom-bootstrap-config

Then restart pod, and run kubectl exec MyPodName -c istio-proxy -- curl 127.0.0.1:15000/config_dump to check the configuration. and there is nothing about “stats_sinks” in the configuration. I’ve also checked the log of envoy container, and i think there is no obviously errors or exceptions.

Is it something wrong in my operation? Appreciate your help, Thanks!

BTW: My istio version is 1.5.1