Secondary resource access with Optional (#782)

Author: csviri

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/reconciler/Context.java

@@ -6,9 +6,9 @@ public interface Context {
 
   Optional<RetryInfo> getRetryInfo();
 
-  default <T> T getSecondaryResource(Class<T> expectedType) {
+  default <T> Optional<T> getSecondaryResource(Class<T> expectedType) {
     return getSecondaryResource(expectedType, null);
   }
 
-  <T> T getSecondaryResource(Class<T> expectedType, String eventSourceName);
+  <T> Optional<T> getSecondaryResource(Class<T> expectedType, String eventSourceName);
 }

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/reconciler/DefaultContext.java

@@ -23,9 +23,9 @@ public Optional<RetryInfo> getRetryInfo() {
   }
 
   @Override
-  public <T> T getSecondaryResource(Class<T> expectedType, String eventSourceName) {
+  public <T> Optional<T> getSecondaryResource(Class<T> expectedType, String eventSourceName) {
     final var eventSource =
         controller.getEventSourceManager().getResourceEventSourceFor(expectedType, eventSourceName);
-    return eventSource.map(es -> es.getAssociated(primaryResource)).orElse(null);
+    return eventSource.map(es -> es.getAssociated(primaryResource));
   }
 }

operator-framework/src/test/java/io/javaoperatorsdk/operator/sample/informereventsource/InformerEventSourceTestCustomReconciler.java

@@ -51,7 +51,8 @@ public UpdateControl<InformerEventSourceTestCustomResource> reconcile(
 
     // Reading the config map from the informer not from the API
     // name of the config map same as custom resource for sake of simplicity
-    ConfigMap configMap = context.getSecondaryResource(ConfigMap.class);
+    ConfigMap configMap = context.getSecondaryResource(ConfigMap.class)
+        .orElseThrow(() -> new IllegalStateException("Config map should be present."));
 
     String targetStatus = configMap.getData().get(TARGET_CONFIG_MAP_KEY);
     LOGGER.debug("Setting target status for CR: {}", targetStatus);

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

@@ -16,7 +16,12 @@
 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.reconciler.*;
+import io.javaoperatorsdk.operator.api.reconciler.Context;
+import io.javaoperatorsdk.operator.api.reconciler.ControllerConfiguration;
+import io.javaoperatorsdk.operator.api.reconciler.EventSourceInitializationContext;
+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.ResourceID;
 import io.javaoperatorsdk.operator.processing.event.source.EventSource;
 import io.javaoperatorsdk.operator.processing.event.source.informer.InformerEventSource;
@@ -63,19 +68,18 @@ public UpdateControl<Tomcat> reconcile(Tomcat tomcat, Context context) {
     createOrUpdateDeployment(tomcat);
     createOrUpdateService(tomcat);
 
-    Deployment deployment = context.getSecondaryResource(Deployment.class);
-
-    if (deployment != null) {
-      Tomcat updatedTomcat =
-          updateTomcatStatus(tomcat, deployment);
-      log.info(
-          "Updating status of Tomcat {} in namespace {} to {} ready replicas",
-          tomcat.getMetadata().getName(),
-          tomcat.getMetadata().getNamespace(),
-          tomcat.getStatus().getReadyReplicas());
-      return UpdateControl.updateStatus(updatedTomcat);
-    }
-    return UpdateControl.noUpdate();
+    return context.getSecondaryResource(Deployment.class)
+        .map(deployment -> {
+          Tomcat updatedTomcat =
+              updateTomcatStatus(tomcat, deployment);
+          log.info(
+              "Updating status of Tomcat {} in namespace {} to {} ready replicas",
+              tomcat.getMetadata().getName(),
+              tomcat.getMetadata().getNamespace(),
+              tomcat.getStatus().getReadyReplicas());
+          return UpdateControl.updateStatus(updatedTomcat);
+        })
+        .orElse(UpdateControl.noUpdate());
   }
 
   private Tomcat updateTomcatStatus(Tomcat tomcat, Deployment deployment) {

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

@@ -70,12 +70,11 @@ public UpdateControl<Webapp> reconcile(Webapp webapp, Context context) {
       return UpdateControl.noUpdate();
     }
 
-    Tomcat tomcat = context.getSecondaryResource(Tomcat.class);
-    if (tomcat == null) {
-      throw new IllegalStateException("Cannot find Tomcat " + webapp.getSpec().getTomcat()
-          + " for Webapp " + webapp.getMetadata().getName() + " in namespace "
-          + webapp.getMetadata().getNamespace());
-    }
+    Tomcat tomcat = context.getSecondaryResource(Tomcat.class)
+        .orElseThrow(
+            () -> new IllegalStateException("Cannot find Tomcat " + webapp.getSpec().getTomcat()
+                + " for Webapp " + webapp.getMetadata().getName() + " in namespace "
+                + webapp.getMetadata().getNamespace()));
 
     if (tomcat.getStatus() != null
         && Objects.equals(tomcat.getSpec().getReplicas(), tomcat.getStatus().getReadyReplicas())) {