feat: process generated CRDs but before they are written out

Fixes #6827

CHANGELOG.md

@@ -17,6 +17,7 @@
 
 * Fix #5993: Support for Kubernetes v1.31 (elli)
 * Fix #6767: Support for Kubernetes v1.32 (penelope) 
+* Fix #6827: Add CRDPostProcessor to process generated CRDs before they are written out
 
 #### _**Note**_: Breaking changes
 

crd-generator/api-v2/src/main/java/io/fabric8/crdv2/generator/CRDGenerator.java

@@ -47,6 +47,7 @@
 public class CRDGenerator {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(CRDGenerator.class);
+  private static final CRDPostProcessor nullProcessor = new CRDPostProcessor() {};
   private final Map<String, AbstractCustomResourceHandler> handlers = new HashMap<>(2);
   private CRDOutput<? extends OutputStream> output;
   private boolean parallel;
@@ -156,7 +157,7 @@ public int generate() {
     return detailedGenerate().numberOfGeneratedCRDs();
   }
 
-  public CRDGenerationInfo detailedGenerate() {
+  public CRDGenerationInfo detailedGenerate(CRDPostProcessor processor) {
     if (getCustomResourceInfos().isEmpty()) {
       LOGGER.warn("No resources were registered with the 'customResources' method to be generated");
       return CRDGenerationInfo.EMPTY;
@@ -192,22 +193,39 @@ public CRDGenerationInfo detailedGenerate() {
 
         if (parallel) {
           handlers.values().stream().map(h -> ForkJoinPool.commonPool().submit(() -> h.handle(info, context.forkContext())))
-              .collect(Collectors.toList()).stream().forEach(ForkJoinTask::join);
+              .collect(Collectors.toList())
+            .forEach(ForkJoinTask::join);
         } else {
-          handlers.values().stream().forEach(h -> h.handle(info, context.forkContext()));
+          handlers.values().forEach(h -> h.handle(info, context.forkContext()));
         }
       }
     }
 
     final CRDGenerationInfo crdGenerationInfo = new CRDGenerationInfo();
     handlers.values().stream().flatMap(AbstractCustomResourceHandler::finish)
-        .forEach(crd -> emitCrd(crd.getKey(), crd.getValue(), crdGenerationInfo));
+        .forEach(crd -> emitCrd(crd.getKey(), crd.getValue(), crdGenerationInfo, processor));
     return crdGenerationInfo;
   }
 
+  public CRDGenerationInfo detailedGenerate() {
+    return detailedGenerate(nullProcessor);
+  }
+
+  /**
+   * @deprecated use {@link #emitCrd(HasMetadata, Set, CRDGenerationInfo, CRDPostProcessor)} instead
+   */
+  @Deprecated(forRemoval = true)
   public void emitCrd(HasMetadata crd, Set<String> dependentClassNames, CRDGenerationInfo crdGenerationInfo) {
+    emitCrd(crd, dependentClassNames, crdGenerationInfo, nullProcessor);
+  }
+
+  protected void emitCrd(HasMetadata crd, Set<String> dependentClassNames, CRDGenerationInfo crdGenerationInfo, CRDPostProcessor processor) {
     final String version = ApiVersionUtil.trimVersion(crd.getApiVersion());
     final String crdName = crd.getMetadata().getName();
+
+    // post-process the CRD if needed
+    crd = processor.process(crd, version);
+
     try {
       final String outputName = getOutputName(crdName, version);
       try (final OutputStreamWriter writer = new OutputStreamWriter(output.outputFor(outputName), StandardCharsets.UTF_8)) {

crd-generator/api-v2/src/main/java/io/fabric8/crdv2/generator/CRDPostProcessor.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2015 Red Hat, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.fabric8.crdv2.generator;
+
+import io.fabric8.kubernetes.api.model.HasMetadata;
+
+public interface CRDPostProcessor {
+
+  /**
+   * Processes the specified CRD (passed as {@link HasMetadata} to be able to handle multiple versions of the CRD spec) after they are generated but before they are written out
+   *
+   * @param crd            the CRD to process as a {@link HasMetadata}
+   * @param crdSpecVersion the CRD specification version of the CRD to process (to be able to cast to the appropriate CRD class)
+   * @return the modified CRD (though, typically, this would just be the CRD specified as input, modified in place)
+   */
+  default HasMetadata process(HasMetadata crd, String crdSpecVersion) {
+    return crd;
+  }
+}