feat(openapi): generation of JsonUnwrapped interface fields

kubernetes-model-generator/openapi/generator/pkg/openapi/openapi-gen-processors.go

@@ -63,9 +63,26 @@ func processPatchComments(_ *generator.Context, _ *types.Package, t *types.Type,
 	}
 }
 
+func addOrAppend(commentLines []string, prefix, value string) []string {
+	added := false
+	for i, commentLine := range commentLines{
+		if strings.HasPrefix(commentLine, prefix) {
+			commentLines[i] = commentLine +","+value
+			added = true
+			break
+		}
+	}
+	if !added {
+		commentLines = append(commentLines, prefix+value)
+	}
+	return commentLines
+}
+
 // func processProtobufOneof
 // To generate interfaces and extending classes for oneof fields
 // This is something extensively used in the Istio API, that uses these as marker interfaces
+//
+// For processing we'll add +k8s:openapi-gen=x-kubernetes tags that will be later processed by kube-openapi and added to the OpenAPI json spec
 func processProtobufOneof(_ *generator.Context, pkg *types.Package, t *types.Type, m *types.Member, memberIndex int) {
 	publicInterfaceName := func(name string) string {
 		if unicode.IsUpper(rune(name[0])) {
@@ -80,8 +97,10 @@ func processProtobufOneof(_ *generator.Context, pkg *types.Package, t *types.Typ
 		m.Type.Kind = types.Struct
 		// Ensure it's exported
 		t.Members[memberIndex].Type.Name.Name = publicInterfaceName(m.Type.Name.Name)
-		// Add comment tag to mark this as an interface, this is later processed by kube-openapi and added to the OpenAPI json spec
-		m.Type.CommentLines = append(m.Type.CommentLines, "+k8s:openapi-gen=x-kubernetes-fabric8-type:interface")
+		//// Add comment tag to the referenced type and mark it as an interface
+		//t.Members[memberIndex].Type.CommentLines = append(m.Type.CommentLines, "+k8s:openapi-gen=x-kubernetes-fabric8-type:interface")
+		// Add comment tag to the current type to mark it as it has fields that are interfaces (useful for the OpenAPI Java generator)
+		t.CommentLines = addOrAppend(t.CommentLines, "+k8s:openapi-gen=x-kubernetes-fabric8-interface-fields:", m.Name)
 	}
 	// Implementations
 	// It's just a marker interface, it contains a single method that has the same name as the interface
@@ -94,17 +113,7 @@ func processProtobufOneof(_ *generator.Context, pkg *types.Package, t *types.Typ
 			}
 			if reflect.ValueOf(t.Methods).MapKeys()[0].String() == reflect.ValueOf(candidateType.Methods).MapKeys()[0].String() {
 				t.CommentLines = append(t.CommentLines, "+k8s:openapi-gen=x-kubernetes-fabric8-implements:"+publicInterfaceName(candidateType.Name.Name))
-				addedImplementation := false
-				for i, candidateCommentLine := range candidateType.CommentLines {
-					if strings.HasPrefix(candidateCommentLine, "+k8s:openapi-gen=x-kubernetes-fabric8-implementation") {
-						candidateType.CommentLines[i] = candidateCommentLine +","+t.Name.Name
-						addedImplementation = true
-						break
-					}
-				}
-				if !addedImplementation {
-					candidateType.CommentLines = append(candidateType.CommentLines, "+k8s:openapi-gen=x-kubernetes-fabric8-implementation:"+t.Name.Name)
-				}
+				candidateType.CommentLines = addOrAppend(candidateType.CommentLines, "+k8s:openapi-gen=x-kubernetes-fabric8-implementation:", t.Name.Name)
 			}
 		}
 	}

kubernetes-model-generator/openapi/maven-plugin/src/main/java/io/fabric8/kubernetes/schema/generator/model/ModelGenerator.java

@@ -121,8 +121,15 @@ private void processTemplate(TemplateContext ret) {
       ret.addImport("com.fasterxml.jackson.databind.annotation.JsonSerialize");
       ret.put("classJsonSerializeUsing", serializer);
     }
-    ret.put("classJsonDeserializeUsing", Optional.ofNullable(deserializerForJavaClass(ret.getClassName()))
-        .orElse("com.fasterxml.jackson.databind.JsonDeserializer.None.class"));
+    final String deserializer;
+    if (SchemaUtils.hasInterfaceFields(ret.getClassSchema())) {
+      deserializer = "io.fabric8.kubernetes.model.jackson.JsonUnwrappedDeserializer.class";
+    } else if (deserializerForJavaClass(ret.getClassName()) != null) {
+      deserializer = deserializerForJavaClass(ret.getClassName());
+    } else {
+      deserializer = "com.fasterxml.jackson.databind.JsonDeserializer.None.class";
+    }
+    ret.put("classJsonDeserializeUsing", deserializer);
     ret.put("package", ret.getPackageName());
     if (settings.isGenerateJavadoc()) {
       ret.put("hasDescription", !sanitizeDescription(ret.getClassSchema().getDescription()).trim().isEmpty());
@@ -162,6 +169,7 @@ private void processTemplate(TemplateContext ret) {
 
   private List<Map<String, Object>> templateFields(TemplateContext templateContext) {
     final List<Map<String, Object>> properties = new ArrayList<>();
+    final Set<String> interfaceFields = SchemaUtils.interfaceFields(templateContext.getClassSchema());
     for (Entry<String, Schema> property : templateContext.getSchemaProperties().entrySet()) {
       final Map<String, Object> templateProp = new HashMap<>();
       final Schema<?> propertySchema = property.getValue();
@@ -190,6 +198,10 @@ private List<Map<String, Object>> templateFields(TemplateContext templateContext
         templateContext.addImport("com.fasterxml.jackson.databind.annotation.JsonDeserialize");
         templateProp.put("deserializeUsing", deserializeUsing);
       }
+      if (interfaceFields.contains(property.getKey())) {
+        templateContext.addImport("com.fasterxml.jackson.annotation.JsonUnwrapped");
+        templateProp.put("jsonUnwrapped", true);
+      }
       // Default values
       if (isArray(propertySchema)) {
         templateContext.addImport("com.fasterxml.jackson.annotation.JsonInclude");

kubernetes-model-generator/openapi/maven-plugin/src/main/java/io/fabric8/kubernetes/schema/generator/model/TemplateContext.java

@@ -26,7 +26,6 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.Objects;
 import java.util.Set;
 import java.util.TreeSet;
 
@@ -55,8 +54,7 @@ final class TemplateContext implements ImportManager {
     inRootPackage = packageName.equals(settings.getPackageName());
     classSimpleName = SchemaUtils.refToClassName(classKey);
     className = packageName + "." + classSimpleName;
-    isInterface = classSchema.getExtensions() != null
-        && Objects.equals(classSchema.getExtensions().get("x-kubernetes-fabric8-type"), "interface");
+    isInterface = SchemaUtils.isInterface(classSchema);
     imports = new TreeSet<>(new ImportOrderComparator());
     kubernetesListType = apiVersion == null ? null : schemaUtils.kubernetesListType(this, classSchema);
     hasMetadata = apiVersion != null && kubernetesListType == null && schemaUtils.isHasMetadata(classSchema);

kubernetes-model-generator/openapi/maven-plugin/src/main/java/io/fabric8/kubernetes/schema/generator/schema/SchemaUtils.java

@@ -253,6 +253,23 @@ public String schemaToClassName(ImportManager imports, Schema<?> schema) {
     return schemaTypeToJavaPrimitive(schema);
   }
 
+  public static boolean isInterface(Schema<?> schema) {
+    return schema.getExtensions() != null
+        && Objects.equals(schema.getExtensions().get("x-kubernetes-fabric8-type"), "interface");
+  }
+
+  public static boolean hasInterfaceFields(Schema<?> schema) {
+    return schema.getExtensions() != null
+        && schema.getExtensions().containsKey("x-kubernetes-fabric8-interface-fields");
+  }
+
+  public static Set<String> interfaceFields(Schema<?> schema) {
+    if (hasInterfaceFields(schema)) {
+      return Set.of(schema.getExtensions().get("x-kubernetes-fabric8-interface-fields").toString().split(","));
+    }
+    return Collections.emptySet();
+  }
+
   public static boolean isArray(Schema<?> schema) {
     return schema instanceof ArraySchema;
   }

kubernetes-model-generator/openapi/maven-plugin/src/main/resources/templates/model_fields.mustache

@@ -37,6 +37,9 @@
 {{#jsonInclude}}
     @JsonInclude(JsonInclude.Include.{{.}})
 {{/jsonInclude}}
+{{#jsonUnwrapped}}
+    @JsonUnwrapped
+{{/jsonUnwrapped}}
     private {{type}} {{name}}{{#defaultValue}} = {{.}}{{/defaultValue}};{{/fields}}
 {{#additionalProperties}}
     @JsonIgnore

kubernetes-model-generator/openapi/maven-plugin/src/main/resources/templates/model_methods.mustache

@@ -25,6 +25,9 @@
 {{#jsonInclude}}
     @JsonInclude(JsonInclude.Include.{{.}})
 {{/jsonInclude}}
+{{#jsonUnwrapped}}
+    @JsonUnwrapped
+{{/jsonUnwrapped}}
     public {{type}} {{getterName}}() {
         return {{name}};
     }

kubernetes-model-generator/openapi/maven-plugin/src/test/java/io/fabric8/kubernetes/schema/generator/SchemaUtilsTest.java

@@ -135,6 +135,13 @@ void serializerForJavaClass(String javaClass, String expected) {
     assertEquals(expected, SchemaUtils.serializerForJavaClass(javaClass));
   }
 
+  @Test
+  void isInterface() {
+    final ObjectSchema schema = new ObjectSchema();
+    schema.setExtensions(Map.of("x-kubernetes-fabric8-type", "interface"));
+    assertTrue(SchemaUtils.isInterface(schema));
+  }
+
   @Nested
   class SchemaToClassName {