feat!: upgrade Fabric8 to 8.0.0 and support Jackson 3

Migrate resource matchers and YAML configuration to Jackson 3, update HTTP client selection and CI to Vert.x 5, and add regression tests and migration guidance.

Author: Mauro de Palma

.github/workflows/build.yml

@@ -23,7 +23,7 @@ jobs:
   httpclient-tests:
     strategy:
       matrix:
-        httpclient: [ 'vertx', 'jdk', 'jetty' ]
+        httpclient: [ 'vertx-5', 'jdk', 'jetty' ]
     uses: ./.github/workflows/integration-tests.yml
     with:
       java-version: 25

.github/workflows/integration-tests.yml

@@ -12,7 +12,7 @@ on:
       http-client:
         type: string
         required: false
-        default: 'vertx'
+        default: 'vertx-5'
       experimental:
         type: boolean
         required: false

docs/content/en/docs/documentation/features.md

@@ -27,21 +27,35 @@ public class DeploymentReconciler
 
 **Note:** This feature is provided by the [Fabric8 Kubernetes Client](https://github.com/fabric8io/kubernetes-client), not JOSDK itself.
 
-To automatically generate CRD manifests from your annotated Custom Resource classes, add this dependency to your project:
+To automatically generate CRD manifests from your annotated Custom Resource classes, configure the
+Fabric8 CRD generator Maven plugin. Use the same Fabric8 version as the SDK:
 
 ```xml
-
-<dependency>
+<plugin>
     <groupId>io.fabric8</groupId>
-    <artifactId>crd-generator-apt</artifactId>
-    <scope>provided</scope>
-</dependency>
+    <artifactId>crd-generator-maven-plugin</artifactId>
+    <version>${fabric8-client.version}</version>
+    <executions>
+        <execution>
+            <goals>
+                <goal>generate</goal>
+            </goals>
+        </execution>
+    </executions>
+</plugin>
 ```
 
-The CRD will be generated in `target/classes/META-INF/fabric8` (or `target/test-classes/META-INF/fabric8` for test scope) with the CRD name suffixed by the generated spec version. 
+Add the plugin under `build/plugins` and set `fabric8-client.version` to `8.0.0`.
+The old `crd-generator-apt` annotation processor was removed in Fabric8 8.
+
+The CRD will be generated in `target/classes/META-INF/fabric8` with the CRD name suffixed by the
+generated spec version. For test resources, configure `classesToScan` to
+`${project.build.testOutputDirectory}` and `classpath` to `WITH_ALL_DEPENDENCIES_AND_TESTS`, and
+bind the plugin execution to `process-test-classes`.
 
-For example, a CR using the `java-operator-sdk.io` group with a `mycrs` plural form will result in these files:
+For example, a CR using the `java-operator-sdk.io` group with a `mycrs` plural form will result in:
 - `mycrs.java-operator-sdk.io-v1.yml`
-- `mycrs.java-operator-sdk.io-v1beta1.yml`
+
+Only `apiextensions.k8s.io/v1` CRDs are generated.
 
 **Note for Quarkus users:** If you're using the `quarkus-operator-sdk` extension, you don't need to add any extra dependency for CRD generation - the extension handles this automatically.

docs/content/en/docs/migration/fabric8-8-migration.md

@@ -0,0 +1,67 @@
+---
+title: Migrating to Fabric8 8 and Jackson 3
+description: Updating operators for Fabric8 Kubernetes Client 8 and Jackson 3
+---
+
+## Fabric8 Kubernetes Client 8
+
+The SDK now uses Fabric8 Kubernetes Client `8.0.0`, which requires Java 17 or newer, matching the
+SDK's existing Java baseline. Align any explicit Fabric8 dependencies and the
+`crd-generator-maven-plugin` with this version.
+
+See the [Fabric8 8 migration guide](https://github.com/fabric8io/kubernetes-client/blob/v8.0.0/doc/MIGRATION-v8.md)
+for the complete list of client and CRD generator changes.
+
+## Jackson 3
+
+The Kubernetes client, resource matchers, and YAML configuration provider now use Jackson 3.
+Code that uses the client's Jackson types must migrate from `com.fasterxml.jackson.core`,
+`com.fasterxml.jackson.databind`, and `com.fasterxml.jackson.dataformat` to the corresponding
+`tools.jackson` packages. Maven dependencies use `tools.jackson.core:jackson-core`,
+`tools.jackson.core:jackson-databind`, and `tools.jackson.dataformat:jackson-dataformat-yaml`.
+Jackson annotations such as `@JsonProperty` remain in `com.fasterxml.jackson.annotation`,
+provided by `com.fasterxml.jackson.core:jackson-annotations`.
+
+Custom serializers, deserializers, and databind annotations must use Jackson 3 types:
+`ValueSerializer`, `ValueDeserializer`, and `tools.jackson.databind.annotation`. Jackson 2
+databind annotations are not used by the client, even when Jackson 2 is also on the classpath.
+Java time support is built in, so remove `JavaTimeModule` registrations.
+
+Jackson 3 mappers are immutable. Use builders instead of `registerModule` or `configure`.
+When supplying a custom mapper to the Kubernetes client, preserve the Fabric8 compatibility
+defaults:
+
+```java
+import io.fabric8.kubernetes.client.KubernetesClientBuilder;
+import io.fabric8.kubernetes.client.utils.KubernetesSerialization;
+import io.fabric8.kubernetes.model.jackson.Jackson2JdkTypesModule;
+import tools.jackson.databind.json.JsonMapper;
+
+var mapper = JsonMapper.builderWithJackson2Defaults()
+    .addModule(new Jackson2JdkTypesModule())
+    .build();
+var client = new KubernetesClientBuilder()
+    .withKubernetesSerialization(new KubernetesSerialization(mapper, true))
+    .build();
+```
+
+The default client already applies these compatibility settings. Supplying a mapper configures
+a copy; the original mapper is not modified. See the Fabric8 migration guide for wire-format
+differences that cannot be restored, and review regenerated CRDs before applying them.
+
+## HTTP client selection
+
+The `operator-framework` module continues to use the JDK HTTP client by default. Fabric8's
+default HTTP client is now `kubernetes-httpclient-vertx-5`, which the core module excludes so
+that it does not bring a second HTTP implementation into operators.
+
+If you select Vert.x through `fabric8-httpclient-impl.name`, use `vertx-5` instead of `vertx`.
+Explicit Vert.x dependencies should use `io.fabric8:kubernetes-httpclient-vertx-5` and compatible
+Vert.x 5 dependencies. Applications depending only on `operator-framework-core` must provide
+their chosen Fabric8 HTTP client implementation.
+
+## CRD generation
+
+Fabric8 removed the `crd-generator-apt` annotation processor. Use the
+[`crd-generator-maven-plugin`](../../documentation/features/#automatic-crd-generation) instead.
+Only `apiextensions.k8s.io/v1` CRDs are generated.

micrometer-support/pom.xml

@@ -64,7 +64,7 @@
     </dependency>
     <dependency>
       <groupId>io.fabric8</groupId>
-      <artifactId>kubernetes-httpclient-vertx</artifactId>
+      <artifactId>kubernetes-httpclient-vertx-5</artifactId>
       <scope>test</scope>
     </dependency>
   </dependencies>

operator-framework-core/pom.xml

@@ -46,10 +46,15 @@
       <exclusions>
         <exclusion>
           <groupId>io.fabric8</groupId>
-          <artifactId>kubernetes-httpclient-okhttp</artifactId>
+          <artifactId>kubernetes-httpclient-vertx-5</artifactId>
         </exclusion>
       </exclusions>
     </dependency>
+    <dependency>
+      <groupId>io.fabric8</groupId>
+      <artifactId>kubernetes-httpclient-${fabric8-httpclient-impl.name}</artifactId>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>org.slf4j</groupId>
       <artifactId>slf4j-api</artifactId>

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/ConfigurationService.java

@@ -49,6 +49,8 @@
 import io.javaoperatorsdk.operator.processing.event.source.informer.pool.DefaultInformerPool;
 import io.javaoperatorsdk.operator.processing.event.source.informer.pool.InformerPool;
 
+import tools.jackson.databind.ObjectMapper;
+
 /** An interface from which to retrieve configuration information. */
 public interface ConfigurationService {
 
@@ -145,11 +147,11 @@ public <R extends HasMetadata> R clone(R object) {
    * you do not need to worry about setting the namespace information in most cases).
    *
    * <p>Previous versions of this class provided direct access to the serialization mechanism (via
-   * {@link com.fasterxml.jackson.databind.ObjectMapper}) or the client's configuration. This was
-   * somewhat confusing, in particular with respect to changes made in the Fabric8 client
-   * serialization architecture made in 6.7. The proper way to configure these aspects is now to
-   * configure the Kubernetes client accordingly and the SDK will extract the information it needs
-   * from this instance. The recommended way to do so is to create your operator with {@link
+   * {@link ObjectMapper}) or the client's configuration. This was somewhat confusing, in particular
+   * with respect to changes made in the Fabric8 client serialization architecture made in 6.7. The
+   * proper way to configure these aspects is now to configure the Kubernetes client accordingly and
+   * the SDK will extract the information it needs from this instance. The recommended way to do so
+   * is to create your operator with {@link
    * io.javaoperatorsdk.operator.Operator#Operator(Consumer)}, passing your custom instance with
    * {@link ConfigurationServiceOverrider#withKubernetesClient(KubernetesClient)}.
    *

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

@@ -25,7 +25,7 @@
 import io.javaoperatorsdk.operator.api.reconciler.Context;
 import io.javaoperatorsdk.operator.processing.dependent.Matcher;
 
-import com.fasterxml.jackson.databind.JsonNode;
+import tools.jackson.databind.JsonNode;
 
 public class GenericKubernetesResourceMatcher<R extends HasMetadata, P extends HasMetadata> {
 

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/matcher/MatcherUtils.java

@@ -20,10 +20,10 @@
 import io.javaoperatorsdk.operator.api.reconciler.Context;
 import io.javaoperatorsdk.operator.api.reconciler.matcher.Matcher;
 
-import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.node.JsonNodeFactory;
-import com.fasterxml.jackson.databind.node.NullNode;
-import com.fasterxml.jackson.databind.node.ObjectNode;
+import tools.jackson.databind.JsonNode;
+import tools.jackson.databind.node.JsonNodeFactory;
+import tools.jackson.databind.node.NullNode;
+import tools.jackson.databind.node.ObjectNode;
 
 /** Shared helpers for the client-side patch based {@link Matcher} implementations. */
 final class MatcherUtils {
@@ -66,9 +66,7 @@ private static JsonNode applyMergePatch(JsonNode target, JsonNode patch) {
     }
     var targetObject =
         target.isObject() ? (ObjectNode) target : JsonNodeFactory.instance.objectNode();
-    var fields = patch.fields();
-    while (fields.hasNext()) {
-      var entry = fields.next();
+    for (var entry : patch.properties()) {
       if (entry.getValue().isNull()) {
         targetObject.remove(entry.getKey());
       } else {

operator-framework-core/src/test/java/io/javaoperatorsdk/operator/processing/event/source/informer/ManagedInformerEventSourceNamespaceChangeTest.java

@@ -161,7 +161,7 @@ private SharedIndexInformer informer() {
         .resources(Deployment.class)
         .inNamespace("ns1")
         .withLabelSelector((String) null)
-        .withShardSelector(null)
+        .withShardSelector((String) null)
         .runnableInformer(0);
   }