envoy.yaml

# https://cloudnative.to/envoy/api-v3/config/route/v3/route_components.proto.html#config-route-v3-routeaction-hashpolicy
# https://stackoverflow.com/questions/69033708/how-to-set-hash-key-value-in-envoy-proxy-for-ring-hash-load-balancing
# https://www.redhat.com/en/blog/configuring-envoy-auto-discover-pods-kubernetes

admin:
  address:
    access_log_path: /dev/stdout
    socket_address: { address: 0.0.0.0, port_value: 9901 }

static_resources:
  listeners:
  - name: listener_0
    address:
      socket_address: { address: 0.0.0.0, port_value: 10000 }
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: ingress_http
          codec_type: AUTO
          route_config:
            name: envoy_pgw_route
            virtual_hosts:
            - name: envoy_pgw_service
              domains: ["*"]
              routes:
              - match: { prefix: "/" }
                route:
                  cluster: pgw_service
                  hash_policy:
                    - header:
                        header_name: ":path" # https://datatracker.ietf.org/doc/html/rfc7540#section-8.1.2.3
          http_filters:
          - name: envoy.filters.http.router
            typed_config:
                  "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router
  clusters:
  - name: pgw_service
    connect_timeout: 0.25s
    type: STATIC
    lb_policy: MAGLEV # https://static.googleusercontent.com/media/research.google.com/en//pubs/archive/44824.pdf
    load_assignment:
      cluster_name: pgw_service
      endpoints:
      - lb_endpoints:
        - endpoint:
            address:
              socket_address:
                address: 172.16.123.177
                port_value: 9091
        - endpoint:
            address:
              socket_address:
                address: 172.16.123.177
                port_value: 9092
        - endpoint:
            address:
              socket_address:
                address: 172.16.123.177
                port_value: 9093
  
  layered_runtime:
  layers:
    - name: static_layer_0
      static_layer:
        envoy:
          resource_limits:
            listener:
              example_listener_name:
                connection_limit: 10000
        overload:
          global_downstream_max_connections: 50000