Merge pull request #4748 from phisco/feat/add-readiness-liveness-probes

feat: add readiness and liveness probes to crossplane

cluster/charts/crossplane/templates/deployment.yaml

@@ -123,9 +123,17 @@ spec:
         name: {{ .Chart.Name }}
         resources:
           {{- toYaml .Values.resourcesCrossplane | nindent 12 }}
-        {{- if or .Values.metrics.enabled (.Values.webhooks.enabled) }}
+        livenessProbe:
+          httpGet:
+            path: /healthz
+            port: healthz
+        readinessProbe:
+          httpGet:
+            path: /readyz
+            port: healthz
         ports:
-        {{- end }}
+        - name: healthz
+          containerPort: 5000
         {{- if .Values.metrics.enabled }}
         - name: metrics
           containerPort: 8080

cmd/crossplane/core/core.go

@@ -36,6 +36,7 @@ import (
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/cache"
 	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/healthz"
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
 
 	"github.com/crossplane/crossplane-runtime/pkg/certificates"
@@ -148,7 +149,7 @@ func (c *startCommand) Run(s *runtime.Scheme, log logging.Logger) error { //noli
 
 	cfg, err := ctrl.GetConfig()
 	if err != nil {
-		return errors.Wrap(err, "Cannot get config")
+		return errors.Wrap(err, "cannot get config")
 	}
 
 	cfg.WarningHandler = rest.NewWarningWriter(os.Stderr, rest.WarningWriterOptions{
@@ -188,9 +189,11 @@ func (c *startCommand) Run(s *runtime.Scheme, log logging.Logger) error { //noli
 		LeaderElectionResourceLock: resourcelock.LeasesResourceLock,
 		LeaseDuration:              func() *time.Duration { d := 60 * time.Second; return &d }(),
 		RenewDeadline:              func() *time.Duration { d := 50 * time.Second; return &d }(),
+
+		HealthProbeBindAddress: ":5000",
 	})
 	if err != nil {
-		return errors.Wrap(err, "Cannot create manager")
+		return errors.Wrap(err, "cannot create manager")
 	}
 
 	o := controller.Options{
@@ -250,7 +253,7 @@ func (c *startCommand) Run(s *runtime.Scheme, log logging.Logger) error { //noli
 			filepath.Join(c.TLSClientCertsDir, corev1.TLSPrivateKeyKey),
 			false)
 		if err != nil {
-			return errors.Wrap(err, "Cannot load TLS certificates for external secret stores")
+			return errors.Wrap(err, "cannot load TLS certificates for external secret stores")
 		}
 
 		o.ESSOptions = &controller.ESSOptions{
@@ -267,7 +270,7 @@ func (c *startCommand) Run(s *runtime.Scheme, log logging.Logger) error { //noli
 	}
 
 	if err := apiextensions.Setup(mgr, ao); err != nil {
-		return errors.Wrap(err, "Cannot setup API extension controllers")
+		return errors.Wrap(err, "cannot setup API extension controllers")
 	}
 
 	po := pkgcontroller.Options{
@@ -282,13 +285,13 @@ func (c *startCommand) Run(s *runtime.Scheme, log logging.Logger) error { //noli
 	if c.CABundlePath != "" {
 		rootCAs, err := ParseCertificatesFromPath(c.CABundlePath)
 		if err != nil {
-			return errors.Wrap(err, "Cannot parse CA bundle")
+			return errors.Wrap(err, "cannot parse CA bundle")
 		}
 		po.FetcherOptions = append(po.FetcherOptions, xpkg.WithCustomCA(rootCAs))
 	}
 
 	if err := pkg.Setup(mgr, po); err != nil {
-		return errors.Wrap(err, "Cannot add packages controllers to manager")
+		return errors.Wrap(err, "cannot add packages controllers to manager")
 	}
 
 	// Registering webhooks with the manager is what actually starts the webhook
@@ -310,5 +313,34 @@ func (c *startCommand) Run(s *runtime.Scheme, log logging.Logger) error { //noli
 		}
 	}
 
-	return errors.Wrap(mgr.Start(ctrl.SetupSignalHandler()), "Cannot start controller manager")
+	if err := c.SetupProbes(mgr); err != nil {
+		return errors.Wrap(err, "cannot setup probes")
+	}
+
+	return errors.Wrap(mgr.Start(ctrl.SetupSignalHandler()), "cannot start controller manager")
+}
+
+// SetupProbes sets up the health and ready probes.
+func (c *startCommand) SetupProbes(mgr ctrl.Manager) error {
+	// Add default readiness probe
+	if err := mgr.AddReadyzCheck("ping", healthz.Ping); err != nil {
+		return errors.Wrap(err, "cannot create ping ready check")
+	}
+
+	// Add default health probe
+	if err := mgr.AddHealthzCheck("ping", healthz.Ping); err != nil {
+		return errors.Wrap(err, "cannot create ping health check")
+	}
+
+	// Add probes waiting for the webhook server if webhooks are enabled
+	if c.WebhookEnabled {
+		hookServer := mgr.GetWebhookServer()
+		if err := mgr.AddReadyzCheck("webhook", hookServer.StartedChecker()); err != nil {
+			return errors.Wrap(err, "cannot create webhook ready check")
+		}
+		if err := mgr.AddHealthzCheck("webhook", hookServer.StartedChecker()); err != nil {
+			return errors.Wrap(err, "cannot create webhook health check")
+		}
+	}
+	return nil
 }