feat(source): fitler by gateway name (#5160)

* feat: filter by gateway name

Signed-off-by: Steven Kreitzer <skre@skre.me>

* address comments

* address comments

* address comments

---------

Signed-off-by: Steven Kreitzer <skre@skre.me>

docs/flags.md

@@ -28,6 +28,7 @@
 | `--[no-]ignore-hostname-annotation` | Ignore hostname annotation when generating DNS names, valid only when --fqdn-template is set (default: false) |
 | `--[no-]ignore-non-host-network-pods` | Ignore pods not running on host network when using pod source (default: true) |
 | `--[no-]ignore-ingress-tls-spec` | Ignore the spec.tls section in Ingress resources (default: false) |
+| `--gateway-name=GATEWAY-NAME` | Limit Gateways of Route endpoints to a specific name (default: all names) |
 | `--gateway-namespace=GATEWAY-NAMESPACE` | Limit Gateways of Route endpoints to a specific namespace (default: all namespaces) |
 | `--gateway-label-filter=GATEWAY-LABEL-FILTER` | Filter Gateways of Route endpoints via label selector (default: all gateways) |
 | `--compatibility=` | Process annotation semantics from legacy implementations (optional, options: mate, molecule, kops-dns-controller) |

docs/sources/gateway-api.md

@@ -100,6 +100,8 @@ spec:
         - --namespace=my-route-namespace
         # Optionally, limit Routes to those matching the given label selector.
         - --label-filter=my-route-label==my-route-value
+        # Optionally, limit Route endpoints to those Gateways with the given name.
+        - --gateway-name=my-gateway-name
         # Optionally, limit Route endpoints to those Gateways in the given namespace.
         - --gateway-namespace=my-gateway-namespace
         # Optionally, limit Route endpoints to those Gateways matching the given label selector.

docs/sources/gateway.md

@@ -43,6 +43,39 @@ Matching Gateways are discovered by iterating over the \*Route's `status.parents
 - Ignores parents with a `parentRef.group` other than
   `gateway.networking.k8s.io` or a `parentRef.kind` other than `Gateway`.
 
+- If the `--gateway-name` flag was specified, ignores parents with a `parentRef.name` other than the
+  specified value.
+
+  For example, given the following HTTPRoute:
+
+    ```yaml
+    apiVersion: gateway.networking.k8s.io/v1
+    kind: HTTPRoute
+    metadata:
+      name: echo
+    spec:
+      hostnames:
+        - echoserver.example.org
+      parentRefs:
+        - group: networking.k8s.io
+          kind: Gateway
+          name: internal
+    ---
+    apiVersion: gateway.networking.k8s.io/v1
+    kind: HTTPRoute
+    metadata:
+      name: echo2
+    spec:
+      hostnames:
+        - echoserver2.example.org
+      parentRefs:
+        - group: networking.k8s.io
+          kind: Gateway
+          name: external
+    ```
+
+  And using the `--gateway-name=external` flag, only the `echo2` HTTPRoute will be considered for DNS entries.
+
 - If the `--gateway-namespace` flag was specified, ignores parents with a `parentRef.namespace` other
   than the specified value.
 

pkg/apis/externaldns/types.go

@@ -61,6 +61,7 @@ type Config struct {
 	IgnoreIngressTLSSpec               bool
 	IgnoreIngressRulesSpec             bool
 	ListenEndpointEvents               bool
+	GatewayName                        string
 	GatewayNamespace                   string
 	GatewayLabelFilter                 string
 	Compatibility                      string
@@ -230,6 +231,7 @@ var defaultConfig = &Config{
 	IgnoreHostnameAnnotation:     false,
 	IgnoreIngressTLSSpec:         false,
 	IgnoreIngressRulesSpec:       false,
+	GatewayName:                  "",
 	GatewayNamespace:             "",
 	GatewayLabelFilter:           "",
 	Compatibility:                "",
@@ -453,6 +455,7 @@ func App(cfg *Config) *kingpin.Application {
 	app.Flag("ignore-hostname-annotation", "Ignore hostname annotation when generating DNS names, valid only when --fqdn-template is set (default: false)").BoolVar(&cfg.IgnoreHostnameAnnotation)
 	app.Flag("ignore-non-host-network-pods", "Ignore pods not running on host network when using pod source (default: true)").BoolVar(&cfg.IgnoreNonHostNetworkPods)
 	app.Flag("ignore-ingress-tls-spec", "Ignore the spec.tls section in Ingress resources (default: false)").BoolVar(&cfg.IgnoreIngressTLSSpec)
+	app.Flag("gateway-name", "Limit Gateways of Route endpoints to a specific name (default: all names)").StringVar(&cfg.GatewayName)
 	app.Flag("gateway-namespace", "Limit Gateways of Route endpoints to a specific namespace (default: all namespaces)").StringVar(&cfg.GatewayNamespace)
 	app.Flag("gateway-label-filter", "Filter Gateways of Route endpoints via label selector (default: all gateways)").StringVar(&cfg.GatewayLabelFilter)
 	app.Flag("compatibility", "Process annotation semantics from legacy implementations (optional, options: mate, molecule, kops-dns-controller)").Default(defaultConfig.Compatibility).EnumVar(&cfg.Compatibility, "", "mate", "molecule", "kops-dns-controller")

source/gateway.go

@@ -82,6 +82,7 @@ func newGatewayInformerFactory(client gateway.Interface, namespace string, label
 }
 
 type gatewayRouteSource struct {
+	gwName      string
 	gwNamespace string
 	gwLabels    labels.Selector
 	gwInformer  informers_v1beta1.GatewayInformer
@@ -161,6 +162,7 @@ func newGatewayRouteSource(clients ClientGenerator, config *Config, kind string,
 	}
 
 	src := &gatewayRouteSource{
+		gwName:      config.GatewayName,
 		gwNamespace: config.GatewayNamespace,
 		gwLabels:    gwLabels,
 		gwInformer:  gwInformer,
@@ -309,6 +311,11 @@ func (c *gatewayRouteResolver) resolve(rt gatewayRoute) (map[string]endpoint.Tar
 			log.Debugf("Gateway %s/%s not found for %s %s/%s", namespace, ref.Name, c.src.rtKind, meta.Namespace, meta.Name)
 			continue
 		}
+		// Confirm the Gateway has the correct name, if specified.
+		if c.src.gwName != "" && c.src.gwName != gw.gateway.Name {
+			log.Debugf("Gateway %s/%s does not match %s %s/%s", namespace, ref.Name, c.src.gwName, meta.Namespace, meta.Name)
+			continue
+		}
 		// Confirm the Gateway has accepted the Route.
 		if !gwRouteIsAccepted(rps.Conditions) {
 			log.Debugf("Gateway %s/%s has not accepted %s %s/%s", namespace, ref.Name, c.src.rtKind, meta.Namespace, meta.Name)

source/gateway_httproute_test.go

@@ -142,6 +142,51 @@ func TestGatewayHTTPRouteSourceEndpoints(t *testing.T) {
 		endpoints       []*endpoint.Endpoint
 		logExpectations []string
 	}{
+		{
+			title: "GatewayName",
+			config: Config{
+				GatewayName: "gateway-name",
+			},
+			namespaces: namespaces("gateway-namespace", "route-namespace"),
+			gateways: []*v1beta1.Gateway{
+				{
+					ObjectMeta: objectMeta("gateway-namespace", "gateway-name"),
+					Spec: v1.GatewaySpec{
+						Listeners: []v1.Listener{{
+							Protocol:      v1.HTTPProtocolType,
+							AllowedRoutes: allowAllNamespaces,
+						}},
+					},
+					Status: gatewayStatus("1.2.3.4"),
+				},
+				{
+					ObjectMeta: objectMeta("gateway-namespace", "not-gateway-name"),
+					Spec: v1.GatewaySpec{
+						Listeners: []v1.Listener{{
+							Protocol:      v1.HTTPProtocolType,
+							AllowedRoutes: allowAllNamespaces,
+						}},
+					},
+					Status: gatewayStatus("2.3.4.5"),
+				},
+			},
+			routes: []*v1beta1.HTTPRoute{{
+				ObjectMeta: objectMeta("route-namespace", "test"),
+				Spec: v1.HTTPRouteSpec{
+					Hostnames: hostnames("test.example.internal"),
+				},
+				Status: httpRouteStatus( // The route is attached to both gateways.
+					gwParentRef("gateway-namespace", "gateway-name"),
+					gwParentRef("gateway-namespace", "not-gateway-name"),
+				),
+			}},
+			endpoints: []*endpoint.Endpoint{
+				newTestEndpoint("test.example.internal", "A", "1.2.3.4"),
+			},
+			logExpectations: []string{
+				"level=debug msg=\"Gateway gateway-namespace/not-gateway-name does not match gateway-name route-namespace/test\"",
+			},
+		},
 		{
 			title: "GatewayNamespace",
 			config: Config{

source/store.go

@@ -54,6 +54,7 @@ type Config struct {
 	IgnoreIngressTLSSpec           bool
 	IgnoreIngressRulesSpec         bool
 	ListenEndpointEvents           bool
+	GatewayName                    string
 	GatewayNamespace               string
 	GatewayLabelFilter             string
 	Compatibility                  string