"transport_api_version": "V3",
      "grpc_services": [
        {
          "google_grpc": {
            "target_uri": "{{ .discovery_address }}",
            "stat_prefix": "googlegrpcxds",
            "channel_credentials": {
              "ssl_credentials": {
                {{ with .xds_root_cert}}"root_certs": {"filename": "{{.}}"}{{ end }}
              }
            },
            "call_credentials": [{
            {{ if .sts }}