cross-node connection use L7 policy, envoy based cilium strategy.

[wkhno]

Proposal / RFE

Is your feature request related to a problem?

Describe the solution you'd like

restful-api based Network Policy program examples and related youtube video I have read, I wonder if the CiliumEnvoyConfig can be more easy to use. In the example it seems to difficult to apply and restart a new one.

here is the L7 traffic management example in the code base.

apiVersion: cilium.io/v2alpha1
kind: CiliumEnvoyConfig
metadata:
  name: envoy-lb-listener
spec:
  services:
    - name: echo-other-node
      namespace: cilium-test
    - name: echo-same-node
      namespace: cilium-test
  resources:
    - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
      name: envoy-lb-listener
      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: envoy-lb-listener
                rds:
                  route_config_name: lb_route
                http_filters:
                  - name: envoy.filters.http.router
    - "@type": type.googleapis.com/envoy.config.route.v3.RouteConfiguration
      name: lb_route
      virtual_hosts:
        - name: "lb_route"
          domains: ["*"]
          routes:
            - match:
                prefix: "/"
              route:
                weighted_clusters:
                  clusters:
                    - name: "cilium-test/echo-same-node"
                      weight: 50
                    - name: "cilium-test/echo-other-node"
                      weight: 50
                retry_policy:
                  retry_on: 5xx
                  num_retries: 3
                  per_try_timeout: 1s
                regex_rewrite:
                  pattern:
                    google_re2: {}
                    regex: "^/foo.*$"
                  substitution: "/"
    - "@type": type.googleapis.com/envoy.config.cluster.v3.Cluster
      name: "cilium-test/echo-same-node"
      connect_timeout: 5s
      lb_policy: ROUND_ROBIN
      type: EDS
      outlier_detection:
        split_external_local_origin_errors: true
        consecutive_local_origin_failure: 2
    - "@type": type.googleapis.com/envoy.config.cluster.v3.Cluster
      name: "cilium-test/echo-other-node"
      connect_timeout: 3s
      lb_policy: ROUND_ROBIN
      type: EDS
      outlier_detection:
        split_external_local_origin_errors: true
        consecutive_local_origin_failure: 2