better early termination of reachability check

Signed-off-by: everettraven <[email protected]>

Author: everettraven

openshift-kube-apiserver/openshiftkubeapiserver/patch.go

@@ -110,20 +110,10 @@ func OpenShiftKubeAPIServerConfigPatch(genericConfig *genericapiserver.Config, k
 	// END HANDLER CHAIN
 
 	openshiftAPIServiceReachabilityCheck := newOpenshiftAPIServiceReachabilityCheck(genericConfig.PublicAddress)
-	oauthAPIServiceReachabilityCheck := newOAuthPIServiceReachabilityCheck(genericConfig.PublicAddress)
-	genericConfig.ReadyzChecks = append(genericConfig.ReadyzChecks, openshiftAPIServiceReachabilityCheck, oauthAPIServiceReachabilityCheck)
 
-	genericConfig.AddPostStartHookOrDie("openshift.io-startkubeinformers", func(context genericapiserver.PostStartHookContext) error {
-		go openshiftInformers.Start(context.StopCh)
-		return nil
-	})
-	genericConfig.AddPostStartHookOrDie("openshift.io-openshift-apiserver-reachable", func(context genericapiserver.PostStartHookContext) error {
-		go openshiftAPIServiceReachabilityCheck.checkForConnection(context)
-		return nil
-	})
-	genericConfig.AddPostStartHookOrDie("openshift.io-oauth-apiserver-reachable", func(context genericapiserver.PostStartHookContext) error {
+    oauthAPIServiceTerminationCondition := func() (bool, string) {
 		authnCache := authncache.NewAuthnCache(openshiftInformers.OpenshiftConfigInformers.Config().V1().Authentications())
-		err := wait.PollImmediate(1*time.Second, 10*time.Second, func() (bool, error) {
+		err := wait.PollImmediate(1*time.Second, 30*time.Second, func() (bool, error) {
 			return authnCache.HasSynced(), nil
 		})
 		if err == nil {
@@ -132,11 +122,25 @@ func OpenShiftKubeAPIServerConfigPatch(genericConfig *genericapiserver.Config, k
 				if auth.Spec.Type == configv1.AuthenticationTypeOIDC {
 					// skip the oauthAPIServiceReachabilityCheck if OIDC
 					// has been configured since the oauth apiserver will be down.
-					return nil
+					return true, "authentication type is OIDC, meaning no oauth-apiserver is deployed. Skipping oauth-apiserver availability check"
 				}
 			}
 		}
+        return false, ""
+    }
+	oauthAPIServiceReachabilityCheck := newOAuthAPIServiceReachabilityCheck(genericConfig.PublicAddress, oauthAPIServiceTerminationCondition)
 
+	genericConfig.ReadyzChecks = append(genericConfig.ReadyzChecks, openshiftAPIServiceReachabilityCheck, oauthAPIServiceReachabilityCheck)
+
+	genericConfig.AddPostStartHookOrDie("openshift.io-startkubeinformers", func(context genericapiserver.PostStartHookContext) error {
+		go openshiftInformers.Start(context.StopCh)
+		return nil
+	})
+	genericConfig.AddPostStartHookOrDie("openshift.io-openshift-apiserver-reachable", func(context genericapiserver.PostStartHookContext) error {
+		go openshiftAPIServiceReachabilityCheck.checkForConnection(context)
+		return nil
+	})
+	genericConfig.AddPostStartHookOrDie("openshift.io-oauth-apiserver-reachable", func(context genericapiserver.PostStartHookContext) error {
 		go oauthAPIServiceReachabilityCheck.checkForConnection(context)
 		return nil
 	})

openshift-kube-apiserver/openshiftkubeapiserver/sdn_readyz_wait.go

@@ -19,25 +19,28 @@ import (
 )
 
 func newOpenshiftAPIServiceReachabilityCheck(ipForKubernetesDefaultService net.IP) *aggregatedAPIServiceAvailabilityCheck {
-	return newAggregatedAPIServiceReachabilityCheck(ipForKubernetesDefaultService, "openshift-apiserver", "api")
+	return newAggregatedAPIServiceReachabilityCheck(ipForKubernetesDefaultService, "openshift-apiserver", "api", nil)
 }
 
-func newOAuthPIServiceReachabilityCheck(ipForKubernetesDefaultService net.IP) *aggregatedAPIServiceAvailabilityCheck {
-	return newAggregatedAPIServiceReachabilityCheck(ipForKubernetesDefaultService, "openshift-oauth-apiserver", "api")
+func newOAuthAPIServiceReachabilityCheck(ipForKubernetesDefaultService net.IP, terminationCondition terminationConditionFunc) *aggregatedAPIServiceAvailabilityCheck {
+	return newAggregatedAPIServiceReachabilityCheck(ipForKubernetesDefaultService, "openshift-oauth-apiserver", "api", terminationCondition)
 }
 
-// if the API service is not found, then this check returns quickly.
+// if the API service is not found or the termination condition is met, then this check returns quickly.
 // if the endpoint is not accessible within 60 seconds, we report ready no matter what
 // otherwise, wait for up to 60 seconds to be able to reach the apiserver
-func newAggregatedAPIServiceReachabilityCheck(ipForKubernetesDefaultService net.IP, namespace, service string) *aggregatedAPIServiceAvailabilityCheck {
+func newAggregatedAPIServiceReachabilityCheck(ipForKubernetesDefaultService net.IP, namespace, service string, terminationCondition terminationConditionFunc) *aggregatedAPIServiceAvailabilityCheck {
 	return &aggregatedAPIServiceAvailabilityCheck{
 		done:                          make(chan struct{}),
 		ipForKubernetesDefaultService: ipForKubernetesDefaultService,
 		namespace:                     namespace,
 		serviceName:                   service,
+		terminationCondition:          terminationCondition,
 	}
 }
 
+type terminationConditionFunc func() (bool, string)
+
 type aggregatedAPIServiceAvailabilityCheck struct {
 	// done indicates that this check is complete (success or failure) and the check should return true
 	done chan struct{}
@@ -50,6 +53,11 @@ type aggregatedAPIServiceAvailabilityCheck struct {
 	namespace string
 	// serviceName is used to get a list of endpoints to directly dial
 	serviceName string
+
+	// terminationCondition is used to determine if conditions are met
+	// to terminate the availability check early. If the conditions are met,
+	// it is expected that true and a message is returned to be logged.
+	terminationCondition terminationConditionFunc
 }
 
 func (c *aggregatedAPIServiceAvailabilityCheck) Name() string {
@@ -75,6 +83,14 @@ func (c *aggregatedAPIServiceAvailabilityCheck) checkForConnection(context gener
 		close(waitUntilCh) // this stops the endpoint check
 		close(c.done)      // once this method is done, the ready check should return true
 	}()
+
+	if c.terminationCondition != nil {
+		if ok, msg := c.terminationCondition(); ok {
+			klog.V(2).Infof("%s early termination condition met: %s", c.Name(), msg)
+			return
+		}
+	}
+
 	start := time.Now()
 
 	kubeClient, err := kubernetes.NewForConfig(context.LoopbackClientConfig)