Kubernetes Ingress `pathType` should be configurable without an additonal `quarkus.kubernetes.ingress.rules` rule

[ThoSap]

Describe the bug

@Sgitario @geoand @iocanel as a continuation of #26747 and with the Kubernetes NGINX Ingress versions >= 1.8.0 warning networking.k8s.io.ingress Creation Warning -> 299 - path /something(/|$)(.*) cannot be used with pathType Prefix when a rewrite is used, it is important that the pathType of the default generated ingress is configurable.

# One of Prefix (default), Exact or ImplementationSpecific
quarkus.kubernetes.ports.http.path-type

https://github.com/kubernetes/ingress-nginx/releases/tag/controller-v1.8.0
https://kubernetes.github.io/ingress-nginx/faq/#validation-of-path
kubernetes/ingress-nginx#11819
https://kubernetes.github.io/ingress-nginx/user-guide/nginx-configuration/configmap/#strict-validate-path-type

I know the following example rewrite does not make sense to you as one could use quarkus.http.root-path, quarkus.http.non-application-root-path, and quarkus.rest.path, but I have a valid use case for a legacy application where I need this rewrite.
The warning will not appear by correctly setting the pathType to ImplementationSpecific using Kubernetes NGINX Ingress versions >= 1.8.0.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /api/$2
  name: my-api
  namespace: my-namespace
spec:
  ingressClassName: nginx
  rules:
    - host: app.example.com
      http:
        paths:
          - backend:
              service:
                name: my-api
                port:
                  number: 8080
            path: /something(/|$)(.*)
            pathType: ImplementationSpecific
  tls:
    - hosts:
        - app.example.com
      secretName: my-certificate

Expected behavior

The developer should be able to configure the default generated ingress pathType using the new configuration property quarkus.kubernetes.ports.http.path-type.

Actual behavior

Currently, it is not possible to configure the generated pathType for the default generated ingress.
It is only possible using an additional rule where one would need to create a dummy path for the default generated ingress rule, and then we need to duplicate configuration option values.

quarkus.kubernetes.ingress.expose=true
# To change the Ingress host. By default, it's empty.
quarkus.kubernetes.ingress.host=prod.svc.url
# Kuberntes NGINX Ingress rewrite annotation
quarkus.kubernetes.ingress.annotations."nginx.ingress.kubernetes.io/rewrite-target"=/api/$2
# To change the Ingress path of the generated Ingress rule. By default, it's "/".
# We must use a dummy here so we don't duplicate the path in the additional rule
quarkus.kubernetes.ports.http.path=/_dummy

quarkus.kubernetes.ingress.rules.1.host=prod.svc.url
quarkus.kubernetes.ingress.rules.1.path=/something(/|$)(.*)
quarkus.kubernetes.ingress.rules.1.path-type=ImplementationSpecific

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    app.kubernetes.io/version: 2.12.9
    app.quarkus.io/quarkus-version: 3.15.1
    app.quarkus.io/build-timestamp: 2024-10-09 - 12:26:48 +0000
    nginx.ingress.kubernetes.io/rewrite-target: /api/$2
  labels:
    app.kubernetes.io/name: my-api
    app.kubernetes.io/version: 2.12.9
    app.kubernetes.io/managed-by: quarkus
  name: my-api
  namespace: my-namespace
spec:
  rules:
    - host: app.example.com
      http:
        paths:
          - backend:
              service:
                name: my-api
                port:
                  name: http
            path: /something(/|$)(.*)
            pathType: ImplementationSpecific
          - backend:
              service:
                name: my-api
                port:
                  name: http
            path: /_dummy
            pathType: Prefix
  tls:
    - hosts:
        - app.example.com
      secretName: my-certificate

How to Reproduce?

No response

Output of uname -a or ver

No response

Output of java -version

Java(TM) SE Runtime Environment Oracle GraalVM 21.0.4+8.1 (build 21.0.4+8-LTS-jvmci-23.1-b41)

Quarkus version or git rev

3.15.1

Build tool (ie. output of mvnw --version or gradlew --version)

8.10.2

Additional information

No response

[quarkus-bot]

/cc @geoand (kubernetes), @iocanel (kubernetes), @radcortez (config)

[ThoSap]

We need the dummy rule as shown above in the actual behavior section, as updating the existing rule does not work when we set the additional rule with the same path and host but a different path-type value than Prefix.

See the integrations test (path-type was left out here):
https://github.com/quarkusio/quarkus/blob/3.15.1/integration-tests/kubernetes/quarkus-standard-way/src/test/java/io/quarkus/it/kubernetes/KubernetesWithIngressRulesTest.java#L81-L88
https://github.com/quarkusio/quarkus/blob/3.15.1/integration-tests/kubernetes/quarkus-standard-way/src/test/resources/kubernetes-with-ingress-rules.properties#L5-L7

This example

quarkus.kubernetes.ingress.expose=true
quarkus.kubernetes.ingress.host=prod.svc.url
quarkus.kubernetes.ingress.annotations."nginx.ingress.kubernetes.io/rewrite-target"=/api/$2
quarkus.kubernetes.ports.http.path=/something(/|$)(.*)

quarkus.kubernetes.ingress.rules.0.host=prod.svc.url
quarkus.kubernetes.ingress.rules.0.path=/something(/|$)(.*)
quarkus.kubernetes.ingress.rules.0.path-type=ImplementationSpecific

generates the following ingress with a duplicate path:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    app.kubernetes.io/version: 2.12.9
    app.quarkus.io/quarkus-version: 3.15.1
    app.quarkus.io/build-timestamp: 2024-10-09 - 12:58:17 +0000
    nginx.ingress.kubernetes.io/rewrite-target: /api/$2
  labels:
    app.kubernetes.io/name: my-api
    app.kubernetes.io/version: 2.12.9
    app.kubernetes.io/managed-by: quarkus
  name: my-api
  namespace: my-namespace
spec:
  rules:
    - host: app.example.com
      http:
        paths:
          - backend:
              service:
                name: my-api
                port:
                  name: http
            path: /something(/|$)(.*)
            pathType: ImplementationSpecific
          - backend:
              service:
                name: my-api
                port:
                  name: http
            path: /something(/|$)(.*)
            pathType: Prefix
  tls:
    - hosts:
        - app.example.com
      secretName: my-certificate

[geoand]

I'll leave this to @iocanel