Merge pull request #898 from jcmoraisjr/jm-check-gateway-default

Check by default if gateway api crds are installed
jcmoraisjr · Feb 4, 2022 · 98b8a99 · 98b8a99
2 parents 2a2e41e + c7ee930
commit 98b8a99
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Showing 4 changed files with 38 additions and 25 deletions.
diff --git a/docs/content/en/docs/configuration/command-line.md b/docs/content/en/docs/configuration/command-line.md
@@ -607,8 +607,11 @@ changes in one single shot. The default value is `200ms`.
 
 Since v0.13
 
-Enables Gateway API watch and parse. The Gateway API CRDs should be installed before enable
-this option. See also the Gateway API configuration [doc]({{% relref "gateway-api" %}}).
+Enables Gateway API watch and parse. This option is enabled by default since v0.14 and controller
+will start the listener only if the Gateway API CRDs are found. Add `--watch-gateway=false`
+option to instruct the controller to not try to listen to the CRDs. The controller should be
+restarted if the CRDs are installed after starting the controller. See also the Gateway API
+configuration [doc]({{% relref "gateway-api" %}}).
 
 ---
 

diff --git a/docs/content/en/docs/configuration/gateway-api.md b/docs/content/en/docs/configuration/gateway-api.md
@@ -14,7 +14,7 @@ The following steps configure the Kubernetes cluster and HAProxy Ingress to read
 
 * Manually install the Gateway API CRDs, see the Gateway API [documentation](https://gateway-api.sigs.k8s.io/v1alpha1/guides/getting-started/#installing-gateway-api-crds-manually)
     * ... or simply `kubectl kustomize "github.com/kubernetes-sigs/gateway-api/config/crd?ref=v0.3.0" | kubectl apply -f -`
-* Add the controller's [`--watch-gateway`]({{% relref "command-line#watch-gateway" %}}) command-line option
+* Start (or restart) the controller
 
 See below the [getting started steps](#getting-started).
 
@@ -58,15 +58,6 @@ kubectl --namespace default create deployment echoserver --image k8s.gcr.io/echo
 kubectl --namespace default expose deployment echoserver --port=8080
 ```
 
-Add the [`--watch-gateway`]({{% relref "command-line#watch-gateway" %}}) command-line option in the `haproxy-ingress-values.yaml` file and [`helm upgrade ...`]({{% relref "/docs/getting-started#installation" %}}) the controller (or simply edit the deployment):
-
-```yaml
-controller:
-  ...
-  extraArgs:
-    watch-gateway: "true"
-```
-
 A GatewayClass enables Gateways to be read and parsed by HAProxy Ingress. Create a GatewayClass with the following content:
 
 ```yaml

diff --git a/pkg/common/ingress/controller/launch.go b/pkg/common/ingress/controller/launch.go
@@ -89,7 +89,7 @@ new /path, e.g., controller-class=staging will make this controller look for
 declare neither the kubernetes.io/ingress.class annotation nor the
 <ingress>.spec.ingressClassName field. Defaults to false`)
 
-		watchGateway = flags.Bool("watch-gateway", false,
+		watchGateway = flags.Bool("watch-gateway", true,
 			`Watch and parse resources from the Gateway API`)
 
 		masterWorker = flags.Bool("master-worker", false,

diff --git a/pkg/controller/listers.go b/pkg/controller/listers.go
@@ -33,6 +33,7 @@ import (
 	"k8s.io/client-go/tools/cache"
 	"k8s.io/client-go/tools/record"
 	gateway "sigs.k8s.io/gateway-api/apis/v1alpha1"
+	"sigs.k8s.io/gateway-api/pkg/client/clientset/versioned"
 	informersgateway "sigs.k8s.io/gateway-api/pkg/client/informers/externalversions"
 	informersgatewayv1alpha1 "sigs.k8s.io/gateway-api/pkg/client/informers/externalversions/apis/v1alpha1"
 	listersgateway "sigs.k8s.io/gateway-api/pkg/client/listers/apis/v1alpha1"
@@ -136,20 +137,38 @@ func createListers(
 	}
 
 	if watchGateway {
-		var option informersgateway.SharedInformerOption
-		if clusterWatch {
-			option = informersgateway.WithTweakListOptions(nil)
+		gv := "networking.x-k8s.io/v1alpha1"
+		hasAPI := false
+		if client, ok := client.(versioned.Interface); ok {
+			resources, err := client.Discovery().ServerResourcesForGroupVersion(gv)
+			if err == nil && resources != nil {
+				names := map[string]bool{}
+				for _, r := range resources.APIResources {
+					names[r.SingularName] = true
+				}
+				hasAPI =
+					names["gatewayclass"] && names["gateway"] && names["httproute"] &&
+						names["tlsroute"] && names["tcproute"] && names["udproute"] && names["backendpolicy"]
+			}
+		}
+		if hasAPI {
+			var option informersgateway.SharedInformerOption
+			if clusterWatch {
+				option = informersgateway.WithTweakListOptions(nil)
+			} else {
+				option = informersgateway.WithNamespace(watchNamespace)
+			}
+			informer := informersgateway.NewSharedInformerFactoryWithOptions(client, resync, option)
+			l.createGatewayLister(informer.Networking().V1alpha1().Gateways())
+			l.createGatewayClassLister(informer.Networking().V1alpha1().GatewayClasses())
+			l.createHTTPRouteLister(informer.Networking().V1alpha1().HTTPRoutes())
+			l.createTLSRouteLister(informer.Networking().V1alpha1().TLSRoutes())
+			l.createTCPRouteLister(informer.Networking().V1alpha1().TCPRoutes())
+			l.createUDPRouteLister(informer.Networking().V1alpha1().UDPRoutes())
+			l.createBackendPolicyLister(informer.Networking().V1alpha1().BackendPolicies())
 		} else {
-			option = informersgateway.WithNamespace(watchNamespace)
+			l.logger.Warn("gateway API '%s' was not found, skipping", gv)
 		}
-		informer := informersgateway.NewSharedInformerFactoryWithOptions(client, resync, option)
-		l.createGatewayLister(informer.Networking().V1alpha1().Gateways())
-		l.createGatewayClassLister(informer.Networking().V1alpha1().GatewayClasses())
-		l.createHTTPRouteLister(informer.Networking().V1alpha1().HTTPRoutes())
-		l.createTLSRouteLister(informer.Networking().V1alpha1().TLSRoutes())
-		l.createTCPRouteLister(informer.Networking().V1alpha1().TCPRoutes())
-		l.createUDPRouteLister(informer.Networking().V1alpha1().UDPRoutes())
-		l.createBackendPolicyLister(informer.Networking().V1alpha1().BackendPolicies())
 	}
 
 	return l