feat(gateway) add support for gateway api experimental ListenerSet

Author: bmhughes

charts/external-dns/templates/clusterrole.yaml

@@ -65,6 +65,9 @@ rules:
   - apiGroups: ["gateway.networking.k8s.io"]
     resources: ["gateways"]
     verbs: ["get","watch","list"]
+  - apiGroups: ["gateway.networking.x-k8s.io"]
+    resources: ["xlistenersets"]
+    verbs: ["get","watch","list"]
 {{- end }}
 {{- if not .Values.namespaced }}
   - apiGroups: [""]
@@ -158,6 +161,9 @@ rules:
   - apiGroups: ["gateway.networking.k8s.io"]
     resources: ["gateways"]
     verbs: ["get","watch","list"]
+  - apiGroups: ["gateway.networking.x-k8s.io"]
+    resources: ["xlistenersets"]
+    verbs: ["get","watch","list"]
 {{- end }}
 {{- end }}
 {{- end }}

docs/flags.md

@@ -32,6 +32,7 @@
 | `--[no-]exclude-unschedulable` | Exclude nodes that are considered unschedulable (default: true) |
 | `--[no-]expose-internal-ipv6` | When using the node source, expose internal IPv6 addresses (optional, default: false) |
 | `--fqdn-template=""` | A templated string that's used to generate DNS names from sources that don't define a hostname themselves, or to add a hostname suffix when paired with the fake source (optional). Accepts comma separated list for multiple global FQDN. |
+| `--[no-]gateway-enable-experimental` | Enable Gateway API experimental (gateway.networking.x-k8s.io) resources (currently only XListenerSet support for routes) |
 | `--gateway-label-filter=""` | Filter Gateways of Route endpoints via label selector (default: all gateways) |
 | `--gateway-name=""` | Limit Gateways of Route endpoints to a specific name (default: all names) |
 | `--gateway-namespace=""` | Limit Gateways of Route endpoints to a specific namespace (default: all namespaces) |

docs/sources/gateway-api.md

@@ -202,6 +202,8 @@ spec:
         - --source=gateway-tlsroute
         - --source=gateway-tcproute
         - --source=gateway-udproute
+        # Optionally, enable Gateway API Experimental resource support (XListenerSet)
+        - --gateway-enable-experimental
         # Optionally, limit Routes to those in the given namespace.
         - --namespace=my-route-namespace
         # Optionally, limit Routes to those matching the given label selector.

docs/sources/gateway.md

@@ -3,6 +3,12 @@
 The gateway-grpcroute, gateway-httproute, gateway-tcproute, gateway-tlsroute, and gateway-udproute
 sources create DNS entries based on their respective `gateway.networking.k8s.io` resources.
 
+## Gateway experimental support
+
+Optionally, [ListenerSet](https://gateway-api.sigs.k8s.io/geps/gep-1713) support can be enabled
+with the flag `--gateway-enable-experimental`. In this case, the `xlistenerset.gateway.networking.x-k8s.io`
+resource listener entries will be appended to the `gateway.networking.k8s.io` listeners.
+
 ## Filtering the Routes considered
 
 These sources support the `--label-filter` flag, which filters \*Route resources
@@ -46,6 +52,9 @@ Matching Gateways are discovered by iterating over the \*Route's `status.parents
 - If the `--gateway-name` flag was specified, ignores parents with a `parentRef.name` other than the
   specified value.
 
+- When [experimental](#gateway-experimental-support) support is enabled the Gateway is expanded from
+  the `parentRef` of the `XListenerSet`.
+
   For example, given the following HTTPRoute:
 
     ```yaml

pkg/apis/externaldns/types.go

@@ -60,6 +60,7 @@ type Config struct {
 	IgnoreIngressRulesSpec                        bool
 	ListenEndpointEvents                          bool
 	ExposeInternalIPV6                            bool
+	GatewayEnableExperimental                     bool
 	GatewayName                                   string
 	GatewayNamespace                              string
 	GatewayLabelFilter                            string
@@ -288,6 +289,7 @@ var defaultConfig = &Config{
 	ExoscaleAPIZone:              "ch-gva-2",
 	ExposeInternalIPV6:           false,
 	FQDNTemplate:                 "",
+	GatewayEnableExperimental:    false,
 	GatewayLabelFilter:           "",
 	GatewayName:                  "",
 	GatewayNamespace:             "",
@@ -626,6 +628,7 @@ func bindFlags(b FlagBinder, cfg *Config) {
 	b.BoolVar("exclude-unschedulable", "Exclude nodes that are considered unschedulable (default: true)", defaultConfig.ExcludeUnschedulable, &cfg.ExcludeUnschedulable)
 	b.BoolVar("expose-internal-ipv6", "When using the node source, expose internal IPv6 addresses (optional, default: false)", false, &cfg.ExposeInternalIPV6)
 	b.StringVar("fqdn-template", "A templated string that's used to generate DNS names from sources that don't define a hostname themselves, or to add a hostname suffix when paired with the fake source (optional). Accepts comma separated list for multiple global FQDN.", defaultConfig.FQDNTemplate, &cfg.FQDNTemplate)
+	b.BoolVar("gateway-enable-experimental", "Enable Gateway API experimental (gateway.networking.x-k8s.io) resources (currently only XListenerSet support for routes)", defaultConfig.GatewayEnableExperimental, &cfg.GatewayEnableExperimental)
 	b.StringVar("gateway-label-filter", "Filter Gateways of Route endpoints via label selector (default: all gateways)", defaultConfig.GatewayLabelFilter, &cfg.GatewayLabelFilter)
 	b.StringVar("gateway-name", "Limit Gateways of Route endpoints to a specific name (default: all names)", defaultConfig.GatewayName, &cfg.GatewayName)
 	b.StringVar("gateway-namespace", "Limit Gateways of Route endpoints to a specific namespace (default: all namespaces)", defaultConfig.GatewayNamespace, &cfg.GatewayNamespace)