extension: cluster router

[AntonKanug]

https://github.com/AntonKanug/built-on-envoy/blob/f3bede6bc6bb1aa1cba67c4d27a091b96f3c9624/extensions/composer/cluster-router/manifest.yaml

[AntonKanug]

Test:

envoy 1 -> envoy 2 -> envoy 3

envoy 1:

10001 listener
  {
                            "envoy_id": "envoy1",
                            "envoy_admin_url": "http://127.0.0.1:9911",
                            "advertise_listen": "0.0.0.0:7001",
                            "peers": [
                              {
                                "id": "envoy2",
                                "endpoint": "http://127.0.0.1:7002",
                                "local_cluster": "peer_envoy2",
                                "weight": 10
                              }
                            ],
                            "poll_interval": "2s",
                            "stale_after": "30s"
}

envoy 2:

envoy 1 connects via 10002 of envoy2
{
                            "envoy_id": "envoy2",
                            "envoy_admin_url": "http://127.0.0.1:9912",
                            "advertise_listen": "0.0.0.0:7002",
                            "peers": [
                              {
                                "id": "envoy3",
                                "endpoint": "http://127.0.0.1:7003",
                                "local_cluster": "peer_envoy3",
                                "weight": 10
                              }
                            ],
                            "poll_interval": "2s",
                            "stale_after": "30s"
}

envoy 3:

envoy 2 connects via 10003 of envoy3
 {
                            "envoy_id": "envoy3",
                            "envoy_admin_url": "http://127.0.0.1:9913",
                            "advertise_listen": "0.0.0.0:7003",
                            "peers": [],
                            "poll_interval": "2s",
                            "stale_after": "30s"
}

has cluster:
    - name: remote_svc
      connect_timeout: 1s
      type: STATIC
      lb_policy: ROUND_ROBIN
      metadata:
        filter_metadata:
          boe.cluster_router:
            role: terminal
      load_assignment:
        cluster_name: remote_svc
        endpoints:
          - lb_endpoints:
              - endpoint:
                  address:
                    socket_address: { address: 127.0.0.1, port_value: 8080 }

test:

curl -i -H 'x-target-cluster: remote_svc' http://127.0.0.1:10001/get
HTTP/1.1 200 OK
server: envoy
date: Fri, 22 May 2026 00:07:30 GMT
content-type: application/json
content-length: 315
access-control-allow-origin: *
access-control-allow-credentials: true
x-envoy-upstream-service-time: 6

{
  "args": {}, 
  "headers": {
    "Accept": "*/*", 
    "Host": "127.0.0.1:10001", 
    "User-Agent": "curl/8.7.1", 
    "X-Boe-Next-Hop": "remote_svc", 
    "X-Envoy-Expected-Rq-Timeout-Ms": "5000", 
    "X-Target-Cluster": "remote_svc"
  }, 
  "origin": "192.168.65.1", 
  "url": "http://127.0.0.1:10001/get"
}

antonk@antonk881-mac cluster-router-test % curl -s 'http://127.0.0.1:7001/advertisements?peer=tester' | jq .
{
  "envoy_id": "envoy1",
  "routes": [
    {
      "target_cluster": "remote_svc",
      "next_hop_local_cluster": "peer_envoy2",
      "distance": 20,
      "as_path": [
        "envoy2",
        "envoy3"
      ]
    }
  ]
}
antonk@antonk881-mac cluster-router-test %  curl -s 'http://127.0.0.1:7002/advertisements?peer=tester' | jq .
{
  "envoy_id": "envoy2",
  "routes": [
    {
      "target_cluster": "remote_svc",
      "next_hop_local_cluster": "peer_envoy3",
      "distance": 10,
      "as_path": [
        "envoy3"
      ]
    }
  ]
}
antonk@antonk881-mac cluster-router-test % curl -s 'http://127.0.0.1:7003/advertisements?peer=tester' | jq .
{
  "envoy_id": "envoy3",
  "routes": [
    {
      "target_cluster": "remote_svc",
      "next_hop_local_cluster": "remote_svc",
      "distance": 0,
      "as_path": null
    }
  ]
}
antonk@antonk881-mac cluster-router-test %