Gateway API HttpRoute with URLRewrite of type: ReplacePrefixMatch ignores other matches conditions like method or headers

[tporeba]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

I noticed that Gateway API HTTPRoutes that use URLRewrite filter with type: ReplacePrefixMatch is silently ignoring matches conditions other than path, for example method or headers, maybe others too.

When I change the type of URLRewrite to ReplaceFullPath then everything is OK.
Here is affected config example:

http_route-prefix_rewrite.yml.txt

apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  creationTimestamp: '2024-10-21T10:41:54Z'
  generation: 14
  labels:
    app.kubernetes.io/instance: kong
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/name: config
    app.kubernetes.io/version: 1.0.0
    argocd.argoproj.io/instance: kong
    helm.sh/chart: config-6.0.0
  name: kong-config-route
  namespace: kong
  resourceVersion: '49961261'
  uid: 5cc9d3ea-7b36-480d-8f60-1ff6461790e4
spec:
  parentRefs:
    - group: gateway.networking.k8s.io
      kind: Gateway
      name: kong
      namespace: kong
  rules:
    - backendRefs:
        - group: ''
          kind: Service
          name: some-service
          namespace: some-namespace
          port: 8904
          weight: 1
      filters:
        - type: URLRewrite
          urlRewrite:
            path:
              replaceFullPath: /some/path/replacement
              type: ReplaceFullPath
      matches:
        - method: POST
          path:
            type: PathPrefix
            value: /some/path/prefix

and json fragment of configuration dumps from KIC obtained by

curl -sv localhost:10256/debug/config/successful

as described in https://docs.konghq.com/kubernetes-ingress-controller/latest/reference/troubleshooting/#dumping-generated-kong-configuration

dump_prefix_rewrite.json

      {
        "connect_timeout": 60000,
        "host": "httproute.kong.kong-config-route._.0",
        "id": "1638e369-7332-5a42-992c-d5dd48183c8f",
        "name": "httproute.kong.kong-config-route._.0",
        "port": 8904,
        "protocol": "http",
        "read_timeout": 1210000,
        "retries": 5,
        "write_timeout": 1210000,
        "tags": [
          "k8s-name:some-service",
          "k8s-namespace:some-namespace",
          "k8s-kind:Service",
          "k8s-uid:d79a6634-9ce2-4c74-a024-c92348f91b2e",
          "k8s-version:v1"
        ],
        "routes": [
          {
            "expression": "(http.path == \"/some/path/prefix\") || (http.path ~ \"^/some/path/prefix(/.*)\")",
            "id": "398f29d3-3965-5c1b-a37d-4174eebcca3c",
            "name": "httproute.kong.kong-config-route._.0.0",
            "preserve_host": true,
            "priority": 35184510504959,
            "strip_path": false,
            "tags": [
              "k8s-name:kong-config-route",
              "k8s-namespace:kong",
              "k8s-kind:HTTPRoute",
              "k8s-uid:5cc9d3ea-7b36-480d-8f60-1ff6461790e4",
              "k8s-group:gateway.networking.k8s.io",
              "k8s-version:v1"
            ],
            "https_redirect_status_code": 426,
            "plugins": [
              {
                "name": "request-transformer",
                "config": {
                  "add": {
                    "body": [],
                    "headers": [],
                    "querystring": []
                  },
                  "append": {
                    "body": [],
                    "headers": [],
                    "querystring": []
                  },
                  "http_method": null,
                  "remove": {
                    "body": [],
                    "headers": [],
                    "querystring": []
                  },
                  "rename": {
                    "body": [],
                    "headers": [],
                    "querystring": []
                  },
                  "replace": {
                    "body": [],
                    "headers": [],
                    "querystring": [],
                    "uri": "/some/path/prefixReplacement$(uri_captures[1])"
                  }
                },
                "enabled": true,
                "protocols": [
                  "grpc",
                  "grpcs",
                  "http",
                  "https"
                ]
              }
            ]
          }
        ]
      }

Notice, that expression does not contain any condition related to the method match.
Same happens with headers and maybe others too.

Expected Behavior

For comparison see the correct behaviour for URLRewrite type ReplaceFullPath:

• http_route-full_rewrite.yml.txt
• dump_full_rewrite.json

The crucial difference is in the expression, where method condition is included, as expected.

"expression": "((http.path == \"/some/path/prefix\") || (http.path ^= \"/some/path/prefix/\")) && (http.method == \"POST\")",

Steps To Reproduce

1. Configure your KIC as described in https://docs.konghq.com/kubernetes-ingress-controller/latest/reference/troubleshooting/#dumping-generated-kong-configuration
2. Install the HTTPRoute from one of objects from attached files to a running cluster with KIC
3. Dump the config of KIC
4. Review the rules and compare the result you get from those two `HTTPRoute` yamls.

You will notice that `(http.method == \"POST\")` condition is not present in one version. 

This can be also confirmed by comparing a `curl -X POST` vs `curl -X GET` on some live configuration - you will see that when `ReplacePrefixMatch` is used, the `GET` requests are also matched by the rule, which is unexpected.

Kong Ingress Controller version

v3.3.1

Kubernetes version

{
  "clientVersion": {
    "major": "1",
    "minor": "29",
    "gitVersion": "v1.29.5",
    "gitCommit": "59755ff595fa4526236b0cc03aa2242d941a5171",
    "gitTreeState": "clean",
    "buildDate": "2024-05-14T10:46:12Z",
    "goVersion": "go1.21.9",
    "compiler": "gc",
    "platform": "linux/amd64"
  },
  "kustomizeVersion": "v5.0.4-0.20230601165947-6ce0bf390ce3",
  "serverVersion": {
    "major": "1",
    "minor": "29",
    "gitVersion": "v1.29.5",
    "gitCommit": "59755ff595fa4526236b0cc03aa2242d941a5171",
    "gitTreeState": "clean",
    "buildDate": "2024-05-14T10:39:39Z",
    "goVersion": "go1.21.9",
    "compiler": "gc",
    "platform": "linux/amd64"
  }
}

Anything else?

No response