feat: operator can be restarted

Author: csviri

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/Operator.java

@@ -137,6 +137,7 @@ public void stop() throws OperatorException {
     if (configurationService.closeClientOnStop()) {
       kubernetesClient.close();
     }
+    started = false;
   }
 
   /**

operator-framework/src/test/java/io/javaoperatorsdk/operator/OperatorRestartIT.java

@@ -0,0 +1,48 @@
+package io.javaoperatorsdk.operator;
+
+import io.javaoperatorsdk.operator.junit.LocallyRunOperatorExtension;
+import io.javaoperatorsdk.operator.sample.informerrelatedbehavior.InformerRelatedBehaviorTestCustomResource;
+import org.junit.jupiter.api.Test;
+
+import io.fabric8.kubernetes.api.model.ObjectMetaBuilder;
+import io.fabric8.kubernetes.client.KubernetesClientBuilder;
+import io.javaoperatorsdk.operator.sample.restart.RestartTestCustomResource;
+import io.javaoperatorsdk.operator.sample.restart.RestartTestReconciler;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.awaitility.Awaitility.await;
+
+class OperatorRestartIT {
+
+  @Test
+  void operatorCanBeRestarted() {
+    try (var client = new KubernetesClientBuilder().build()) {
+      LocallyRunOperatorExtension.applyCrd(RestartTestCustomResource.class,
+              client);
+      Operator operator = new Operator();
+      var reconciler = new RestartTestReconciler();
+      operator.register(reconciler);
+      operator.start();
+
+      client.resource(testCustomResource()).createOrReplace();
+      await().untilAsserted(() -> {
+        assertThat(reconciler.getNumberOfExecutions()).isGreaterThan(0);
+      });
+      var reconcileNumberBeforeStop = reconciler.getNumberOfExecutions();
+      operator.stop();
+      operator.start();
+
+      await().untilAsserted(() -> {
+        assertThat(reconciler.getNumberOfExecutions()).isGreaterThan(reconcileNumberBeforeStop);
+      });
+    }
+  }
+
+  RestartTestCustomResource testCustomResource() {
+    RestartTestCustomResource cr = new RestartTestCustomResource();
+    cr.setMetadata(new ObjectMetaBuilder()
+        .withName("test1")
+        .build());
+    return cr;
+  }
+}

operator-framework/src/test/java/io/javaoperatorsdk/operator/sample/restart/ConfigMapDependentResource.java

@@ -0,0 +1,35 @@
+package io.javaoperatorsdk.operator.sample.restart;
+
+import java.util.Map;
+
+import io.fabric8.kubernetes.api.model.ConfigMap;
+import io.fabric8.kubernetes.api.model.ConfigMapBuilder;
+import io.fabric8.kubernetes.api.model.ObjectMetaBuilder;
+import io.javaoperatorsdk.operator.api.reconciler.Context;
+import io.javaoperatorsdk.operator.processing.dependent.kubernetes.CRUDKubernetesDependentResource;
+import io.javaoperatorsdk.operator.processing.dependent.kubernetes.KubernetesDependent;
+
+@KubernetesDependent(labelSelector = "app=restart-test")
+public class ConfigMapDependentResource
+    extends CRUDKubernetesDependentResource<ConfigMap, RestartTestCustomResource> {
+
+  public static final String DATA_KEY = "key";
+
+  public ConfigMapDependentResource() {
+    super(ConfigMap.class);
+  }
+
+  @Override
+  protected ConfigMap desired(RestartTestCustomResource primary,
+      Context<RestartTestCustomResource> context) {
+    return new ConfigMapBuilder()
+        .withMetadata(new ObjectMetaBuilder()
+            .withLabels(Map.of("app", "restart-test"))
+            .withName(primary.getMetadata().getName())
+            .withNamespace(primary.getMetadata().getNamespace())
+            .build())
+        .withData(Map.of(DATA_KEY, primary.getMetadata().getName()))
+        .build();
+
+  }
+}

operator-framework/src/test/java/io/javaoperatorsdk/operator/sample/restart/RestartTestCustomResource.java

@@ -0,0 +1,15 @@
+package io.javaoperatorsdk.operator.sample.restart;
+
+import io.fabric8.kubernetes.api.model.Namespaced;
+import io.fabric8.kubernetes.client.CustomResource;
+import io.fabric8.kubernetes.model.annotation.Group;
+import io.fabric8.kubernetes.model.annotation.ShortNames;
+import io.fabric8.kubernetes.model.annotation.Version;
+
+@Group("sample.javaoperatorsdk")
+@Version("v1")
+@ShortNames("rt")
+public class RestartTestCustomResource
+    extends CustomResource<Void, Void>
+    implements Namespaced {
+}

operator-framework/src/test/java/io/javaoperatorsdk/operator/sample/restart/RestartTestReconciler.java

@@ -0,0 +1,31 @@
+package io.javaoperatorsdk.operator.sample.restart;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+import io.javaoperatorsdk.operator.api.reconciler.Context;
+import io.javaoperatorsdk.operator.api.reconciler.ControllerConfiguration;
+import io.javaoperatorsdk.operator.api.reconciler.Reconciler;
+import io.javaoperatorsdk.operator.api.reconciler.UpdateControl;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.Dependent;
+import io.javaoperatorsdk.operator.support.TestExecutionInfoProvider;
+
+@ControllerConfiguration(
+    dependents = @Dependent(type = ConfigMapDependentResource.class))
+public class RestartTestReconciler
+    implements Reconciler<RestartTestCustomResource>, TestExecutionInfoProvider {
+
+  private final AtomicInteger numberOfExecutions = new AtomicInteger(0);
+
+  @Override
+  public UpdateControl<RestartTestCustomResource> reconcile(
+      RestartTestCustomResource resource,
+      Context<RestartTestCustomResource> context) {
+    numberOfExecutions.addAndGet(1);
+    return UpdateControl.noUpdate();
+  }
+
+  public int getNumberOfExecutions() {
+    return numberOfExecutions.get();
+  }
+
+}