envoy_bootstrap_tmpl.json

# cat /var/lib/istio/envoy/envoy_bootstrap_tmpl.json
{
  "node": {
    "id": "{{ .nodeID }}",
    "cluster": "{{ .cluster }}",
{{ if .zone }}
    "locality": {
        "zone": "{{ .zone }}"
    },
{{ end }}
    "metadata": {{ .meta_json_str }}
    },
    "stats_config": {
    "use_all_default_tags": false,
    "stats_tags": [{
        "tag_name": "cluster_name",
        "regex": "^cluster\\.((.+?(\\..+?\\.svc\\.cluster\\.local)?)\\.)"
      },
      {
        "tag_name": "tcp_prefix",
        "regex": "^tcp\\.((.*?)\\.)\\w+?$"
      },
      {
        "tag_name": "response_code",
        "regex": "_rq(_(\\d{3}))$"
      },
      {
        "tag_name": "response_code_class",
        "regex": "_rq(_(\\dxx))$"
      },
      {
        "tag_name": "http_conn_manager_listener_prefix",
        "regex": "^listener(?=\\.).*?\\.http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "http_conn_manager_prefix",
        "regex": "^http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "listener_address",
        "regex": "^listener\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      }
    ]
  },
  "admin": {
    "access_log_path": "/dev/null",
    "address": {
      "socket_address": {
        "address": "127.0.0.1",
        "port_value": 15000
      }
    }
  },
  "dynamic_resources": {
    "lds_config": {
        "ads": {}
    },
    "cds_config": {
        "ads": {}
    },
    "ads_config": {
      "api_type": "GRPC",
      "refresh_delay": "{{ .refresh_delay }}",
      "grpc_services": [
        {
          "envoy_grpc": {
            "cluster_name": "xds-grpc"
          }
        }
      ]
    }
  },
  "static_resources": {
    "clusters": [
    {
      "name": "prometheus_stats",
      "type": "STATIC",
      "connect_timeout": "0.250s",
      "lb_policy": "ROUND_ROBIN",
      "hosts": [{
        "socket_address": {
          "protocol": "TCP",
          "address": "127.0.0.1",
          "port_value": 15000,
        }
      }],
    },
    {
    "name": "xds-grpc",
    "type": "STRICT_DNS",
    "connect_timeout": "{{ .connect_timeout }}",
    "lb_policy": "ROUND_ROBIN",
{{ if eq .config.ControlPlaneAuthPolicy 1 }}
      "tls_context": {
        "common_tls_context": {
          "alpn_protocols": ["h2"],
          "tls_certificates": [{
            "certificate_chain": {
              "filename": "/etc/certs/cert-chain.pem"
            },
            "private_key": {
              "filename": "/etc/certs/key.pem"
            }
          }],
          "validation_context": {
            "trusted_ca": {
              "filename": "/etc/certs/root-cert.pem"
            },
            "verify_subject_alt_name": [
              {{- range $a, $s := .pilot_SAN }}
              "{{$s}}"
              {{- end}}
            ]
          }
        }
      },
{{ end }}
    "hosts": [
    {
    "socket_address": {{ .pilot_grpc_address }}
    }
    ],
    "circuit_breakers": {
        "thresholds": [
      {
        "priority": "DEFAULT",
        "max_connections": 100000,
        "max_pending_requests": 100000,
        "max_requests": 100000
      },
      {
        "priority": "HIGH",
        "max_connections": 100000,
        "max_pending_requests": 100000,
        "max_requests": 100000
      }]
    },
    "upstream_connection_options": {
      "tcp_keepalive": {
        "keepalive_time": 300
      }
    },
    "http2_protocol_options": { }
    }

    {{ if .zipkin }}
    ,
      {
        "name": "zipkin",
        "type": "STRICT_DNS",
        "connect_timeout": "1s",
        "lb_policy": "ROUND_ROBIN",
        "hosts": [
          {
            "socket_address": {{ .zipkin }}
          }
        ]
      }
      {{ end }}
    ],
    "listeners":[
      {
        "address": {
          "socket_address": {
            "protocol": "TCP",
            "address": "0.0.0.0",
            "port_value": 15090,
          }
        },
        "filter_chains": [{
          "filters": [{
            "name": "envoy.http_connection_manager",
            "config": {
              "codec_type": "AUTO",
              "stat_prefix": "stats",
              "route_config": {
                "virtual_hosts": [{
                  "name": "backend",
                  "domains": [
                    "*"
                  ],
                  "routes": [{
                    "match": {
                      "prefix": "/stats/prometheus"
                    },
                    "route": {
                      "cluster": "prometheus_stats"
                    }
                  }]
                }]
              },
              "http_filters": {
                "name": "envoy.router"
              }
            }
          }]
        }],
      },
    ],
  },
  {{ if .zipkin }}
  "tracing": {
    "http": {
      "name": "envoy.zipkin",
      "config": {
        "collector_cluster": "zipkin"
      }
    }
  },
  {{ end }}
  {{ if .statsd }}
  "stats_sinks": [
    {
      "name": "envoy.statsd",
      "config": {
        "address": {
          "socket_address": {{ .statsd }}
        }
      }
    }
  ]
  {{ end }}
}