refactor: TomcatReconciler now uses dependent resources support

Author: metacosm

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

@@ -0,0 +1,45 @@
+package io.javaoperatorsdk.operator.sample;
+
+import io.fabric8.kubernetes.api.model.ObjectMeta;
+import io.fabric8.kubernetes.api.model.apps.Deployment;
+import io.fabric8.kubernetes.api.model.apps.DeploymentBuilder;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.Builder;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.Updater;
+
+public class DeploymentDependentResource
+    implements Builder<Deployment, Tomcat>, Updater<Deployment, Tomcat> {
+
+  @Override
+  public Deployment buildFor(Tomcat tomcat) {
+    Deployment deployment = TomcatReconciler.loadYaml(Deployment.class, "deployment.yaml");
+    final ObjectMeta tomcatMetadata = tomcat.getMetadata();
+    final String tomcatName = tomcatMetadata.getName();
+    return new DeploymentBuilder(deployment)
+        .editMetadata()
+        .addToLabels("app", tomcatName)
+        .withName(tomcatName)
+        .withNamespace(tomcatMetadata.getNamespace())
+        .addToLabels("app.kubernetes.io/part-of", tomcatName)
+        .addToLabels("app.kubernetes.io/managed-by", "tomcat-operator")
+        .endMetadata()
+        .editSpec()
+        .withReplicas(tomcat.getSpec().getReplicas())
+        // set tomcat version
+        .editTemplate()
+        // make sure label selector matches label (which has to be matched by service selector too)
+        .editMetadata().addToLabels("app", tomcatName).endMetadata()
+        .editSpec()
+        .editFirstContainer().withImage("tomcat:" + tomcat.getSpec().getVersion()).endContainer()
+        .endSpec()
+        .endTemplate()
+        .endSpec()
+        .build();
+  }
+
+  @Override
+  public Deployment update(Deployment fetched, Tomcat tomcat) {
+    return new DeploymentBuilder(fetched).editSpec().editTemplate().editSpec().editFirstContainer()
+        .withImage("tomcat:" + tomcat.getSpec().getVersion())
+        .endContainer().endSpec().endTemplate().endSpec().build();
+  }
+}

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

@@ -7,60 +7,49 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import io.fabric8.kubernetes.api.model.OwnerReference;
+import io.fabric8.kubernetes.api.model.ObjectMeta;
 import io.fabric8.kubernetes.api.model.Service;
+import io.fabric8.kubernetes.api.model.ServiceBuilder;
 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.informers.SharedIndexInformer;
 import io.fabric8.kubernetes.client.utils.Serialization;
-import io.javaoperatorsdk.operator.api.config.Cloner;
 import io.javaoperatorsdk.operator.api.reconciler.Context;
 import io.javaoperatorsdk.operator.api.reconciler.ControllerConfiguration;
-import io.javaoperatorsdk.operator.api.reconciler.EventSourceInitializer;
 import io.javaoperatorsdk.operator.api.reconciler.Reconciler;
 import io.javaoperatorsdk.operator.api.reconciler.UpdateControl;
-import io.javaoperatorsdk.operator.processing.event.source.EventSourceRegistry;
-import io.javaoperatorsdk.operator.processing.event.source.InformerEventSource;
-import io.javaoperatorsdk.operator.processing.event.source.Mappers;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.DependentResourceConfiguration;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.Updater;
 
 import static io.javaoperatorsdk.operator.api.reconciler.Constants.NO_FINALIZER;
 
 /**
  * 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(finalizerName = NO_FINALIZER)
-public class TomcatReconciler implements Reconciler<Tomcat>, EventSourceInitializer<Tomcat> {
+@ControllerConfiguration(
+    finalizerName = NO_FINALIZER,
+    labelSelector = "app.kubernetes.io/managed-by=tomcat-operator",
+    dependents = {
+        @DependentResourceConfiguration(resourceType = Deployment.class,
+            updatable = true, builder = DeploymentDependentResource.class,
+            updater = DeploymentDependentResource.class),
+        @DependentResourceConfiguration(resourceType = Service.class, creatable = false,
+            updatable = true)
+    })
+public class TomcatReconciler implements Reconciler<Tomcat>, Updater<Service, Tomcat> {
 
   private final Logger log = LoggerFactory.getLogger(getClass());
 
   private final KubernetesClient kubernetesClient;
 
-  private volatile InformerEventSource<Deployment, Tomcat> informerEventSource;
-
   public TomcatReconciler(KubernetesClient client) {
     this.kubernetesClient = client;
   }
 
   @Override
-  public void prepareEventSources(EventSourceRegistry<Tomcat> eventSourceRegistry, Cloner cloner) {
-    SharedIndexInformer<Deployment> deploymentInformer =
-        kubernetesClient.apps().deployments().inAnyNamespace()
-            .withLabel("app.kubernetes.io/managed-by", "tomcat-operator")
-            .runnableInformer(0);
-
-    this.informerEventSource =
-        new InformerEventSource<>(deploymentInformer, Mappers.fromOwnerReference(), cloner);
-    eventSourceRegistry.registerEventSource(this.informerEventSource);
-  }
-
-  @Override
-  public UpdateControl<Tomcat> reconcile(Tomcat tomcat, Context context) {
-    createOrUpdateDeployment(tomcat);
-    createOrUpdateService(tomcat);
-
-    Deployment deployment = informerEventSource.getAssociated(tomcat);
+  public UpdateControl<Tomcat> reconcile(Tomcat tomcat, Context<Tomcat> context) {
+    Deployment deployment = context.getSecondaryResource(Deployment.class);
 
     if (deployment != null) {
       Tomcat updatedTomcat =
@@ -85,78 +74,22 @@ private Tomcat updateTomcatStatus(Tomcat tomcat, Deployment deployment) {
     return tomcat;
   }
 
-  private void createOrUpdateDeployment(Tomcat tomcat) {
-    String ns = tomcat.getMetadata().getNamespace();
-    Deployment existingDeployment =
-        kubernetesClient
-            .apps()
-            .deployments()
-            .inNamespace(ns)
-            .withName(tomcat.getMetadata().getName())
-            .get();
-    if (existingDeployment == null) {
-      Deployment deployment = loadYaml(Deployment.class, "deployment.yaml");
-      deployment.getMetadata().setName(tomcat.getMetadata().getName());
-      deployment.getMetadata().setNamespace(ns);
-      deployment.getMetadata().getLabels().put("app.kubernetes.io/part-of",
-          tomcat.getMetadata().getName());
-      deployment.getMetadata().getLabels().put("app.kubernetes.io/managed-by", "tomcat-operator");
-      // set tomcat version
-      deployment
-          .getSpec()
-          .getTemplate()
-          .getSpec()
-          .getContainers()
-          .get(0)
-          .setImage("tomcat:" + tomcat.getSpec().getVersion());
-      deployment.getSpec().setReplicas(tomcat.getSpec().getReplicas());
-
-      // make sure label selector matches label (which has to be matched by service selector too)
-      deployment
-          .getSpec()
-          .getTemplate()
-          .getMetadata()
-          .getLabels()
-          .put("app", tomcat.getMetadata().getName());
-      deployment
-          .getSpec()
-          .getSelector()
-          .getMatchLabels()
-          .put("app", tomcat.getMetadata().getName());
-
-      OwnerReference ownerReference = deployment.getMetadata().getOwnerReferences().get(0);
-      ownerReference.setName(tomcat.getMetadata().getName());
-      ownerReference.setUid(tomcat.getMetadata().getUid());
-
-      log.info("Creating or updating Deployment {} in {}", deployment.getMetadata().getName(), ns);
-      kubernetesClient.apps().deployments().inNamespace(ns).create(deployment);
-    } else {
-      existingDeployment
-          .getSpec()
-          .getTemplate()
-          .getSpec()
-          .getContainers()
-          .get(0)
-          .setImage("tomcat:" + tomcat.getSpec().getVersion());
-      existingDeployment.getSpec().setReplicas(tomcat.getSpec().getReplicas());
-      kubernetesClient.apps().deployments().inNamespace(ns).createOrReplace(existingDeployment);
-    }
-  }
-
-  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);
+  @Override
+  public Service update(Service fetched, Tomcat tomcat) {
+    final ObjectMeta tomcatMetadata = tomcat.getMetadata();
+    return new ServiceBuilder(loadYaml(Service.class, "service.yaml"))
+        .editMetadata()
+        .withName(tomcatMetadata.getName())
+        .withNamespace(tomcatMetadata.getNamespace())
+        .endMetadata()
+        .editSpec()
+        .addToSelector("app", tomcatMetadata.getName())
+        .endSpec()
+        .build();
   }
 
-  private <T> T loadYaml(Class<T> clazz, String yaml) {
-    try (InputStream is = getClass().getResourceAsStream(yaml)) {
+  static <T> T loadYaml(Class<T> clazz, String yaml) {
+    try (InputStream is = TomcatReconciler.class.getResourceAsStream(yaml)) {
       return Serialization.unmarshal(is, clazz);
     } catch (IOException ex) {
       throw new IllegalStateException("Cannot find yaml on classpath: " + yaml);