gateway api: support RouteNamespaces

Co-authored-by: Jean-Baptiste Doumenjou <925513+jbdoumenjou@users.noreply.github.com>

pkg/provider/kubernetes/gateway/fixtures/httproute/with_namespace_all.yml

@@ -0,0 +1,68 @@
+---
+kind: GatewayClass
+apiVersion: networking.x-k8s.io/v1alpha1
+metadata:
+  name: my-gateway-class
+spec:
+  controller: traefik.io/gateway-controller
+
+---
+kind: Gateway
+apiVersion: networking.x-k8s.io/v1alpha1
+metadata:
+  name: my-gateway
+  namespace: default
+spec:
+  gatewayClassName: my-gateway-class
+  listeners:  # Use GatewayClass defaults for listener definition.
+    - protocol: HTTP
+      port: 80
+      routes:
+        kind: HTTPRoute
+        namespaces:
+          from: All
+        selector:
+          matchLabels:
+            app: foo
+
+---
+kind: HTTPRoute
+apiVersion: networking.x-k8s.io/v1alpha1
+metadata:
+  name: http-app-default
+  namespace: default
+  labels:
+    app: foo
+spec:
+  hostnames:
+    - "foo.com"
+  rules:
+    - matches:
+        - path:
+            type: Exact
+            value: /foo
+      forwardTo:
+        - serviceName: whoami
+          port: 80
+          weight: 1
+
+---
+kind: HTTPRoute
+apiVersion: networking.x-k8s.io/v1alpha1
+metadata:
+  name: http-app-bar
+  namespace: bar
+  labels:
+    app: foo
+spec:
+  hostnames:
+    - "bar.com"
+  rules:
+    - matches:
+        - path:
+            type: Exact
+            value: /bar
+      forwardTo:
+        - serviceName: whoami-bar
+          port: 80
+          weight: 1

pkg/provider/kubernetes/gateway/fixtures/httproute/with_namespace_same.yml

@@ -0,0 +1,68 @@
+---
+kind: GatewayClass
+apiVersion: networking.x-k8s.io/v1alpha1
+metadata:
+  name: my-gateway-class
+spec:
+  controller: traefik.io/gateway-controller
+
+---
+kind: Gateway
+apiVersion: networking.x-k8s.io/v1alpha1
+metadata:
+  name: my-gateway
+  namespace: default
+spec:
+  gatewayClassName: my-gateway-class
+  listeners:  # Use GatewayClass defaults for listener definition.
+    - protocol: HTTP
+      port: 80
+      routes:
+        kind: HTTPRoute
+        namespaces:
+          from: Same
+        selector:
+          matchLabels:
+            app: foo
+
+---
+kind: HTTPRoute
+apiVersion: networking.x-k8s.io/v1alpha1
+metadata:
+  name: http-app-default
+  namespace: default
+  labels:
+    app: foo
+spec:
+  hostnames:
+    - "foo.com"
+  rules:
+    - matches:
+        - path:
+            type: Exact
+            value: /foo
+      forwardTo:
+        - serviceName: whoami
+          port: 80
+          weight: 1
+
+---
+kind: HTTPRoute
+apiVersion: networking.x-k8s.io/v1alpha1
+metadata:
+  name: http-app-bar
+  namespace: bar
+  labels:
+    app: foo
+spec:
+  hostnames:
+    - "bar.com"
+  rules:
+    - matches:
+        - path:
+            type: Exact
+            value: /bar
+      forwardTo:
+        - serviceName: whoami-bar
+          port: 80
+          weight: 1

pkg/provider/kubernetes/gateway/fixtures/httproute/with_namespace_selector.yml

@@ -0,0 +1,79 @@
+---
+kind: Namespace
+apiVersion: v1
+metadata:
+  name: bar
+  labels:
+    foo: bar
+
+---
+kind: GatewayClass
+apiVersion: networking.x-k8s.io/v1alpha1
+metadata:
+  name: my-gateway-class
+spec:
+  controller: traefik.io/gateway-controller
+
+---
+kind: Gateway
+apiVersion: networking.x-k8s.io/v1alpha1
+metadata:
+  name: my-gateway
+  namespace: default
+spec:
+  gatewayClassName: my-gateway-class
+  listeners:  # Use GatewayClass defaults for listener definition.
+    - protocol: HTTP
+      port: 80
+      routes:
+        kind: HTTPRoute
+        namespaces:
+          from: Selector
+          selector:
+            matchLabels:
+              foo: bar
+        selector:
+          matchLabels:
+            app: foo
+
+---
+kind: HTTPRoute
+apiVersion: networking.x-k8s.io/v1alpha1
+metadata:
+  name: http-app-default
+  namespace: default
+  labels:
+    app: foo
+spec:
+  hostnames:
+    - "foo.com"
+  rules:
+    - matches:
+        - path:
+            type: Exact
+            value: /foo
+      forwardTo:
+        - serviceName: whoami
+          port: 80
+          weight: 1
+
+---
+kind: HTTPRoute
+apiVersion: networking.x-k8s.io/v1alpha1
+metadata:
+  name: http-app-bar
+  namespace: bar
+  labels:
+    app: foo
+spec:
+  hostnames:
+    - "bar.com"
+  rules:
+    - matches:
+        - path:
+            type: Exact
+            value: /bar
+      forwardTo:
+        - serviceName: whoami-bar
+          port: 80
+          weight: 1