Generating route fails for wildcard hosts due to invalid name

[robinmanuelthiel]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

The following ingress

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: wildcard-domain
  annotations:
    konghq.com/strip-path: 'true'
    konghq.com/preserve-host: 'true'
spec:
  ingressClassName: 'kong'
  rules:
  - host: '*.foo.com'
    http:
      paths:
      - path: /
        pathType: ImplementationSpecific
        backend:
          service:
            name: foo-service
            port:
              number: 80

tries to generate a route object that looks like this

{
  "protocols": [
    "http",
    "https"
  ],
  "paths": [
    "/"
  ],
  "methods": null,
  "sources": null,
  "hosts": [
    "*.foo.com"
  ],
  "name": "sbc-dev.wildcard-domain.foo-service.*.foo.com.80", // <-- invalid due to the asterisk (*)
  "created_at": 1672412759,
  "updated_at": 1672412759,
  "headers": null,
  "request_buffering": true,
  "response_buffering": true,
  "https_redirect_status_code": 426,
  "tags": null,
  "destinations": null,
  "preserve_host": true,
  "regex_priority": 0,
  "strip_path": true,
  "snis": null,
  "service": {
    "id": "cf59b775-dcf7-52e1-add6-ce91f55acba9"
  },
  "path_handling": "v0",
  "id": "f37b8676-2de6-567b-9cf6-90d9d1bcb5cb"
}

This won't be accepted by the Admin API giving the following error (from the kong-proxy logs):

time="2022-12-30T15:26:23Z" level=error msg="could not update kong admin" error="posting new config to /config: HTTP status 400 (message: \"declarative config is invalid: {services={{routes={[2]={name=\\\"invalid value 'sbc-dev.subscriptions-ingress.subscriptions-spaceblocks-subscriptions-main.*.subscriptions.eu1.dev.spaceblocks.cloud.80': the only accepted ascii characters are alphanumerics or ., -, _, and ~\\\"}}}}}\")" subsystem=dataplane-synchronizer

Expected Behavior

The route should be generated successfully.

Steps To Reproduce

See above. Pls note, that the service and ingress resource are in the same namespace, which is different from the kong namespace

Kong Ingress Controller version

v3.1

Kubernetes version

No response

Anything else?

1.23

[robinmanuelthiel]

It might have worked in the past, as this user here reported a successful route generation of a similar Ingress object: https://discuss.konghq.com/t/workaround-kubernetes-ingress-to-allow-wildcard-hosts/5015

[robinmanuelthiel]

Looks like the new combined routes feature is root of this problem.

My current solution is to downgrade to version 2.7 (Helm Chart Version 2.13.1), which does not have the CombinedRoutes feature flag enabled.

[randmonkey]

Looks like the new combined routes feature is root of this problem.

My current solution is to downgrade to version 2.7 (Helm Chart Version 2.13.1), which does not have the CombinedRoutes feature flag enabled.

You can also turn off CombinedRoutes by setting CONTROLLER_FEATURE_GATES=CombinedRoutes=false in 2.8.0. It is verified OK to use wildcard hosts.

[robinmanuelthiel]

You can also turn off CombinedRoutes by setting CONTROLLER_FEATURE_GATES=CombinedRoutes=false in 2.8.0. It is verified OK to use wildcard hosts.

Thanks, is there a straight-forward way to set this via Helm?

[randmonkey]

You can also turn off CombinedRoutes by setting CONTROLLER_FEATURE_GATES=CombinedRoutes=false in 2.8.0. It is verified OK to use wildcard hosts.

Thanks, is there a straight-forward way to set this via Helm?

It could be configured by ingressController.env.feature_gates.
Add such section in values.yaml:

ingressController:
  env:
    feature_gates: "CombinedRoutes=false"