refactor: tomcat example improvements

sample-operators/tomcat-operator/src/main/java/io/javaoperatorsdk/operator/sample/TomcatReconciler.java

@@ -13,23 +13,21 @@
 import io.fabric8.kubernetes.api.model.apps.Deployment;
 import io.fabric8.kubernetes.api.model.apps.DeploymentStatus;
 import io.fabric8.kubernetes.client.KubernetesClient;
-import io.fabric8.kubernetes.client.dsl.RollableScalableResource;
-import io.fabric8.kubernetes.client.dsl.ServiceResource;
 import io.fabric8.kubernetes.client.informers.SharedIndexInformer;
 import io.fabric8.kubernetes.client.utils.Serialization;
-import io.javaoperatorsdk.operator.api.*;
 import io.javaoperatorsdk.operator.api.reconciler.*;
 import io.javaoperatorsdk.operator.processing.event.ResourceID;
 import io.javaoperatorsdk.operator.processing.event.source.EventSourceRegistry;
 import io.javaoperatorsdk.operator.processing.event.source.InformerEventSource;
 
+import static io.javaoperatorsdk.operator.api.reconciler.ControllerConfiguration.NO_FINALIZER;
 import static java.util.Collections.EMPTY_SET;
 
 /**
  * Runs a specified number of Tomcat app server Pods. It uses a Deployment to create the Pods. Also
  * creates a Service over which the Pods can be accessed.
  */
-@ControllerConfiguration
+@ControllerConfiguration(finalizerName = NO_FINALIZER)
 public class TomcatReconciler implements Reconciler<Tomcat>, EventSourceInitializer<Tomcat> {
 
   private final Logger log = LoggerFactory.getLogger(getClass());
@@ -81,13 +79,6 @@ public UpdateControl<Tomcat> reconcile(Tomcat tomcat, Context context) {
     return UpdateControl.noUpdate();
   }
 
-  @Override
-  public DeleteControl cleanup(Tomcat tomcat, Context context) {
-    deleteDeployment(tomcat);
-    deleteService(tomcat);
-    return DeleteControl.defaultDelete();
-  }
-
   private Tomcat updateTomcatStatus(Tomcat tomcat, Deployment deployment) {
     DeploymentStatus deploymentStatus =
         Objects.requireNonNullElse(deployment.getStatus(), new DeploymentStatus());
@@ -156,41 +147,18 @@ private void createOrUpdateDeployment(Tomcat tomcat) {
     }
   }
 
-  private void deleteDeployment(Tomcat tomcat) {
-    log.info("Deleting Deployment {}", tomcat.getMetadata().getName());
-    RollableScalableResource<Deployment> deployment =
-        kubernetesClient
-            .apps()
-            .deployments()
-            .inNamespace(tomcat.getMetadata().getNamespace())
-            .withName(tomcat.getMetadata().getName());
-    if (deployment.get() != null) {
-      deployment.delete();
-    }
-  }
-
   private void createOrUpdateService(Tomcat tomcat) {
     Service service = loadYaml(Service.class, "service.yaml");
     service.getMetadata().setName(tomcat.getMetadata().getName());
     String ns = tomcat.getMetadata().getNamespace();
     service.getMetadata().setNamespace(ns);
+    service.getMetadata().getOwnerReferences().get(0).setName(tomcat.getMetadata().getName());
+    service.getMetadata().getOwnerReferences().get(0).setUid(tomcat.getMetadata().getUid());
     service.getSpec().getSelector().put("app", tomcat.getMetadata().getName());
     log.info("Creating or updating Service {} in {}", service.getMetadata().getName(), ns);
     kubernetesClient.services().inNamespace(ns).createOrReplace(service);
   }
 
-  private void deleteService(Tomcat tomcat) {
-    log.info("Deleting Service {}", tomcat.getMetadata().getName());
-    ServiceResource<Service> service =
-        kubernetesClient
-            .services()
-            .inNamespace(tomcat.getMetadata().getNamespace())
-            .withName(tomcat.getMetadata().getName());
-    if (service.get() != null) {
-      service.delete();
-    }
-  }
-
   private <T> T loadYaml(Class<T> clazz, String yaml) {
     try (InputStream is = getClass().getResourceAsStream(yaml)) {
       return Serialization.unmarshal(is, clazz);

sample-operators/tomcat-operator/src/main/java/io/javaoperatorsdk/operator/sample/WebappReconciler.java

@@ -17,6 +17,7 @@
 import io.fabric8.kubernetes.client.KubernetesClient;
 import io.fabric8.kubernetes.client.dsl.ExecListener;
 import io.fabric8.kubernetes.client.dsl.ExecWatch;
+import io.fabric8.kubernetes.client.informers.cache.Cache;
 import io.javaoperatorsdk.operator.api.reconciler.Context;
 import io.javaoperatorsdk.operator.api.reconciler.ControllerConfiguration;
 import io.javaoperatorsdk.operator.api.reconciler.DeleteControl;
@@ -40,9 +41,11 @@ public WebappReconciler(KubernetesClient kubernetesClient) {
     this.kubernetesClient = kubernetesClient;
   }
 
+  private InformerEventSource<Tomcat> tomcatEventSource;
+
   @Override
   public void prepareEventSources(EventSourceRegistry<Webapp> eventSourceRegistry) {
-    InformerEventSource<Tomcat> tomcatEventSource =
+    tomcatEventSource =
         new InformerEventSource<>(kubernetesClient, Tomcat.class, t -> {
           // To create an event to a related WebApp resource and trigger the reconciliation
           // we need to find which WebApp this Tomcat custom resource is related to.
@@ -67,9 +70,9 @@ public UpdateControl<Webapp> reconcile(Webapp webapp, Context context) {
       return UpdateControl.noUpdate();
     }
 
-    var tomcatClient = kubernetesClient.customResources(Tomcat.class);
-    Tomcat tomcat = tomcatClient.inNamespace(webapp.getMetadata().getNamespace())
-        .withName(webapp.getSpec().getTomcat()).get();
+    Tomcat tomcat = tomcatEventSource.getStore()
+        .getByKey(Cache.namespaceKeyFunc(webapp.getMetadata().getNamespace(),
+            webapp.getSpec().getTomcat()));
     if (tomcat == null) {
       throw new IllegalStateException("Cannot find Tomcat " + webapp.getSpec().getTomcat()
           + " for Webapp " + webapp.getMetadata().getName() + " in namespace "

sample-operators/tomcat-operator/src/main/resources/io/javaoperatorsdk/operator/sample/service.yaml

@@ -2,6 +2,11 @@ apiVersion: v1
 kind: Service
 metadata:
   name: ""
+  ownerReferences: # used for finding which Tomcat does this Deployment belong to
+    - apiVersion: apps/v1
+      kind: Tomcat
+      name: ""
+      uid: ""
 spec:
   selector:
     app: ""