Add Gateway API HTTPRoute support to Helm chart

Add HTTPRoute template as alternative to Ingress for exposing
Kubernetes Dashboard via Gateway API. Kong proxy service is used
as backend, maintaining compatibility with current architecture.

Features:
- HTTPRoute template with Gateway API v1
- Configuration via values.yaml app.httproute section
- Dynamic Kong proxy port selection (TLS/HTTP)
- Support for custom parentRefs, hostnames, and rules
- Compatible with existing Ingress configuration

Tested with Cilium Gateway Controller in local cluster.
HTTPRoute successfully created and accepted by gateway controller.

Fixes #10384

Signed-off-by: Aleksei Sviridkin <f@lex.la>
Co-Authored-By: Claude <noreply@anthropic.com>

Author: lexfrei

charts/kubernetes-dashboard/Chart.yaml

@@ -14,7 +14,7 @@
 
 apiVersion: v2
 name: kubernetes-dashboard
-version: 7.13.0
+version: 7.14.0
 description: General-purpose web UI for Kubernetes clusters
 keywords:
   - kubernetes

charts/kubernetes-dashboard/templates/networking/httproute.yaml

@@ -0,0 +1,60 @@
+# Copyright 2025 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+{{- if and .Values.app.httproute.enabled (eq .Values.app.mode "dashboard")}}
+
+# Determine the service port to use for the HTTPRoute configuration
+# If TLS is enabled in the HTTPRoute configuration, use the TLS service port.
+# Otherwise, fall back to the HTTP service port.
+{{- $servicePort := (ternary 443 80 .Values.app.httproute.tls.enabled) }}
+
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: {{ template "kubernetes-dashboard.name" . }}
+  labels:
+    {{- include "kubernetes-dashboard.labels" . | nindent 4 }}
+    {{- with .Values.app.httproute.labels }}
+    {{- toYaml . | nindent 4 }}
+    {{- end }}
+  annotations:
+    {{- include "kubernetes-dashboard.annotations" . | nindent 4 }}
+    {{- with .Values.app.httproute.annotations }}
+    {{- toYaml . | nindent 4 }}
+    {{- end }}
+spec:
+  {{- with .Values.app.httproute.parentRefs }}
+  parentRefs:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+  {{- with .Values.app.httproute.hostnames }}
+  hostnames:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+  rules:
+    {{- range .Values.app.httproute.rules }}
+    - {{- with .matches }}
+      matches:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
+      {{- with .filters }}
+      filters:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
+      backendRefs:
+        - name: {{ template "kong.fullname" (index $.Subcharts "kong") }}-proxy
+          port: {{ $servicePort }}
+          weight: 1
+    {{- end }}
+{{- end }}

charts/kubernetes-dashboard/values.yaml

@@ -135,6 +135,43 @@ app:
       secretName: ""
     labels: {}
     annotations: {}
+
+  # Gateway API HTTPRoute configuration
+  # NOTE: Requires Gateway API CRDs (v1) installed in cluster
+  # https://gateway-api.sigs.k8s.io/guides/getting-started/
+  httproute:
+    # Enable HTTPRoute resource (alternative to Ingress)
+    enabled: false
+    # Additional HTTPRoute labels
+    labels: {}
+    # Additional HTTPRoute annotations
+    annotations: {}
+    # Gateway references
+    # Must reference an existing Gateway resource
+    parentRefs: []
+      # - name: example-gateway
+      #   namespace: gateway-system
+      #   sectionName: https
+    # List of hostnames
+    hostnames: []
+      # - dashboard.example.com
+    # HTTPRoute rules
+    rules:
+      - matches:
+          - path:
+              type: PathPrefix
+              value: /
+        # Optional filters:
+        # filters:
+        #   - type: RequestHeaderModifier
+        #     requestHeaderModifier:
+        #       add:
+        #         - name: X-Custom-Header
+        #           value: value
+    # TLS configuration (determines Kong proxy port: 443 for TLS, 80 for HTTP)
+    tls:
+      enabled: true
+
   # Use the following toleration if Dashboard can be deployed on a tainted control-plane nodes
   # - key: node-role.kubernetes.io/control-plane
   #   effect: NoSchedule