feat: provide more exception context on workflow errors (#1699)

* feat: provide more exception context on workflow errors

* refactor: simplify

* docs: improve wording

Author: metacosm

docs/documentation/patterns-best-practices.md

@@ -91,7 +91,7 @@ done automatically, the whole process can be completely transparent.
 ## Managing State
 
 Thanks to the declarative nature of Kubernetes resources, operators that deal only with
-Kubernetes resources can operator in a stateless fashion, i.e. they do not need to maintain
+Kubernetes resources can operate in a stateless fashion, i.e. they do not need to maintain
 information about the state of these resources, as it should be possible to completely rebuild
 the resource state from its representation (that's what declarative means, after all).
 However, this usually doesn't hold true anymore when dealing with external resources, and it

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

@@ -1,7 +1,10 @@
 package io.javaoperatorsdk.operator;
 
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.util.Collections;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.stream.Collectors;
 
 public class AggregatedOperatorException extends OperatorException {
@@ -22,7 +25,15 @@ public Map<String, Exception> getAggregatedExceptions() {
   @Override
   public String getMessage() {
     return super.getMessage() + " " + causes.entrySet().stream()
-        .map(entry -> entry.getKey() + " -> " + entry.getValue())
-        .collect(Collectors.joining("\n - ", "Details:\n", ""));
+        .map(entry -> entry.getKey() + " -> " + exceptionDescription(entry))
+        .collect(Collectors.joining("\n - ", "Details:\n - ", ""));
+  }
+
+  private static String exceptionDescription(Entry<String, Exception> entry) {
+    final var exception = entry.getValue();
+    final var out = new StringWriter(2000);
+    final var stringWriter = new PrintWriter(out);
+    exception.printStackTrace(stringWriter);
+    return out.toString();
   }
 }

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

@@ -60,8 +60,7 @@ static <K extends HasMetadata> Map<String, EventSource> nameEventSourcesFromDepe
   }
 
   /**
-   * This is for the use case when the event sources are not access explicitly by name in the
-   * reconciler.
+   * Used when event sources are not explicitly named when created/registered.
    *
    * @param eventSource EventSource
    * @return generated name

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

@@ -32,12 +32,12 @@ public interface DependentResource<R, P extends HasMetadata> {
   Class<R> resourceType();
 
   /**
-   * Dependent resources are designed to by default provide event sources. There are cases where it
-   * might not:
+   * Dependent resources are designed to by default provide event sources. There are cases where
+   * they might not:
    * <ul>
    * <li>If an event source is shared between multiple dependent resources. In this case only one or
-   * none of the dependent resources sharing the event source should provide one.</li>
-   * <li>Some special implementation of an event source. That just execute some action might not
+   * none of the dependent resources sharing the event source should provide one, if any.</li>
+   * <li>Some special implementation of an event source that just executes some action might not
    * provide one.</li>
    * </ul>
    *

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/dependent/AbstractExternalDependentResource.java

@@ -33,14 +33,11 @@ protected AbstractExternalDependentResource(Class<R> resourceType) {
   public void resolveEventSource(EventSourceRetriever<P> eventSourceRetriever) {
     super.resolveEventSource(eventSourceRetriever);
     if (isDependentResourceWithExplicitState) {
-      externalStateEventSource = (InformerEventSource<?, P>) dependentResourceWithExplicitState
-          .eventSourceName()
-          .map(n -> eventSourceRetriever
-              .getResourceEventSourceFor(dependentResourceWithExplicitState.stateResourceClass(),
-                  (String) n))
-          .orElseGet(() -> eventSourceRetriever
-              .getResourceEventSourceFor(
-                  (Class<R>) dependentResourceWithExplicitState.stateResourceClass()));
+      final var eventSourceName = (String) dependentResourceWithExplicitState
+          .eventSourceName().orElse(null);
+      externalStateEventSource = (InformerEventSource<?, P>) eventSourceRetriever
+          .getResourceEventSourceFor(dependentResourceWithExplicitState.stateResourceClass(),
+              eventSourceName);
     }
 
   }
@@ -65,13 +62,13 @@ public void delete(P primary, Context<P> context) {
     }
   }
 
-  @SuppressWarnings("unchecked")
+  @SuppressWarnings({"unchecked", "unused"})
   private void handleExplicitStateDelete(P primary, R secondary, Context<P> context) {
     var res = dependentResourceWithExplicitState.stateResource(primary, secondary);
     dependentResourceWithExplicitState.getKubernetesClient().resource(res).delete();
   }
 
-  @SuppressWarnings({"rawtypes", "unchecked"})
+  @SuppressWarnings({"rawtypes", "unchecked", "unused"})
   protected void handleExplicitStateCreation(P primary, R created, Context<P> context) {
     var resource = dependentResourceWithExplicitState.stateResource(primary, created);
     var stateResource =

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/EventSourceManager.java

@@ -1,8 +1,8 @@
 package io.javaoperatorsdk.operator.processing.event;
 
-import java.util.*;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
 import java.util.function.Function;
@@ -213,11 +213,6 @@ public ControllerResourceEventSource<P> getControllerResourceEventSource() {
     return eventSources.controllerResourceEventSource();
   }
 
-  @Override
-  public <R> ResourceEventSource<R, P> getResourceEventSourceFor(Class<R> dependentType) {
-    return getResourceEventSourceFor(dependentType, null);
-  }
-
   public <R> List<ResourceEventSource<R, P>> getResourceEventSourcesFor(Class<R> dependentType) {
     return eventSources.getEventSources(dependentType);
   }

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/EventSourceRetriever.java

@@ -7,11 +7,11 @@
 
 public interface EventSourceRetriever<P extends HasMetadata> {
 
-  <R> ResourceEventSource<R, P> getResourceEventSourceFor(
-      Class<R> dependentType);
+  default <R> ResourceEventSource<R, P> getResourceEventSourceFor(Class<R> dependentType) {
+    return getResourceEventSourceFor(dependentType, null);
+  }
 
-  <R> ResourceEventSource<R, P> getResourceEventSourceFor(
-      Class<R> dependentType, String name);
+  <R> ResourceEventSource<R, P> getResourceEventSourceFor(Class<R> dependentType, String name);
 
   <R> List<ResourceEventSource<R, P>> getResourceEventSourcesFor(Class<R> dependentType);
 

operator-framework/src/test/java/io/javaoperatorsdk/operator/sample/externalstate/externalstatebulkdependent/BulkDependentResourceExternalWithState.java

@@ -1,13 +1,19 @@
 package io.javaoperatorsdk.operator.sample.externalstate.externalstatebulkdependent;
 
-import java.util.*;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
 import java.util.stream.Collectors;
 
 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.*;
+import io.javaoperatorsdk.operator.processing.dependent.BulkDependentResource;
+import io.javaoperatorsdk.operator.processing.dependent.BulkUpdater;
+import io.javaoperatorsdk.operator.processing.dependent.DependentResourceWithExplicitState;
+import io.javaoperatorsdk.operator.processing.dependent.Matcher;
 import io.javaoperatorsdk.operator.processing.dependent.external.PerResourcePollingDependentResource;
 import io.javaoperatorsdk.operator.support.ExternalIDGenServiceMock;
 import io.javaoperatorsdk.operator.support.ExternalResource;
@@ -36,10 +42,10 @@ public Set<ExternalResource> fetchResources(
         getExternalStateEventSource().getSecondaryResources(primaryResource);
     Set<ExternalResource> res = new HashSet<>();
 
-    configMaps.stream().forEach(cm -> {
+    configMaps.forEach(cm -> {
       var id = cm.getData().get(ID_KEY);
       var externalResource = externalService.read(id);
-      externalResource.ifPresent(er -> res.add(er));
+      externalResource.ifPresent(res::add);
     });
     return res;
   }