Support oneOf constraint in CRD schemas

Signed-off-by: Tom Bentley <[email protected]>

crd-generator/src/main/java/io/strimzi/crdgenerator/CrdGenerator.java

@@ -22,6 +22,7 @@
 import io.strimzi.crdgenerator.annotations.Example;
 import io.strimzi.crdgenerator.annotations.Maximum;
 import io.strimzi.crdgenerator.annotations.Minimum;
+import io.strimzi.crdgenerator.annotations.OneOf;
 import io.strimzi.crdgenerator.annotations.Pattern;
 import io.strimzi.crdgenerator.annotations.Type;
 
@@ -311,12 +312,40 @@ private void buildObjectSchema(ObjectNode result, Class<?> crdClass, boolean pri
         }
 
         result.set("properties", buildSchemaProperties(crdClass));
+        ArrayNode oneOf = buildSchemaOneOf(crdClass);
+        if (oneOf != null) {
+            result.set("oneOf", oneOf);
+        }
         ArrayNode required = buildSchemaRequired(crdClass);
         if (required.size() > 0) {
             result.set("required", required);
         }
     }
 
+    private ArrayNode buildSchemaOneOf(Class<?> crdClass) {
+        ArrayNode alternatives;
+        OneOf oneOf = crdClass.getAnnotation(OneOf.class);
+        if (oneOf != null && oneOf.value().length > 0) {
+            alternatives = nf.arrayNode();
+            for (OneOf.Alternative alt : oneOf.value()) {
+                ObjectNode alternative = alternatives.addObject();
+                ObjectNode properties = alternative.putObject("properties");
+                for (OneOf.Alternative.Property prop: alt.value()) {
+                    properties.putObject(prop.value());
+                }
+                ArrayNode required = alternative.putArray("required");
+                for (OneOf.Alternative.Property prop: alt.value()) {
+                    if (prop.required()) {
+                        required.add(prop.value());
+                    }
+                }
+            }
+        } else {
+            alternatives = null;
+        }
+        return alternatives;
+    }
+
     private void checkClass(Class<?> crdClass) {
         if (!crdClass.isAnnotationPresent(JsonInclude.class)) {
             err(crdClass + " is missing @JsonInclude");

crd-generator/src/main/java/io/strimzi/crdgenerator/annotations/OneOf.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright Strimzi authors.
+ * License: Apache License 2.0 (see the file LICENSE or http://apache.org/licenses/LICENSE-2.0.html).
+ */
+package io.strimzi.crdgenerator.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.TYPE})
+public @interface OneOf {
+    /** @return List of alternatives */
+    Alternative[] value();
+
+    @interface Alternative {
+
+        @interface Property {
+            /** @return The name of a property */
+            String value();
+            /** @return Whether this property is required */
+            boolean required() default true;
+        }
+
+        /** @return Properties in this alternative */
+        Property[] value();
+    }
+}
+

crd-generator/src/test/java/io/strimzi/crdgenerator/CrdGeneratorTest.java

@@ -14,8 +14,7 @@
 import java.util.LinkedHashMap;
 import java.util.Map;
 
-import static org.hamcrest.CoreMatchers.is;
-import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class CrdGeneratorTest {
     @Test
@@ -24,7 +23,7 @@ public void simpleTest() throws IOException, URISyntaxException {
         StringWriter w = new StringWriter();
         crdGenerator.generate(ExampleCrd.class, w);
         String s = w.toString();
-        assertThat(CrdTestUtils.readResource("simpleTest.yaml"), is(s));
+        assertEquals(CrdTestUtils.readResource("simpleTest.yaml"), s);
     }
 
     @Test
@@ -39,6 +38,6 @@ public void generateHelmMetadataLabels() throws IOException {
         StringWriter w = new StringWriter();
         crdGenerator.generate(ExampleCrd.class, w);
         String s = w.toString();
-        assertThat(CrdTestUtils.readResource("simpleTestHelmMetadata.yaml"), is(s));
+        assertEquals(CrdTestUtils.readResource("simpleTestHelmMetadata.yaml"), s);
     }
 }

crd-generator/src/test/java/io/strimzi/crdgenerator/ExampleCrd.java

@@ -15,6 +15,7 @@
 import io.strimzi.crdgenerator.annotations.Example;
 import io.strimzi.crdgenerator.annotations.KubeLink;
 import io.strimzi.crdgenerator.annotations.Minimum;
+import io.strimzi.crdgenerator.annotations.OneOf;
 import io.strimzi.crdgenerator.annotations.Pattern;
 
 import java.util.List;
@@ -42,6 +43,7 @@
         )
     }
     ))
+@OneOf({@OneOf.Alternative(@OneOf.Alternative.Property("either")), @OneOf.Alternative(@OneOf.Alternative.Property("or"))})
 public class ExampleCrd<T, U extends Number, V extends U> extends CustomResource {
 
     private String ignored;
@@ -107,6 +109,9 @@ public class ExampleCrd<T, U extends Number, V extends U> extends CustomResource
 
     public List<? extends List<? extends U>> listOfWildcardTypeVar4;
 
+    private String either;
+    private String or;
+
 
     @Description("Example of complex type.")
     public static class ObjectProperty {

crd-generator/src/test/resources/io/strimzi/crdgenerator/simpleTest.yaml

@@ -414,5 +414,14 @@ spec:
         stringProperty:
           type: "string"
           pattern: ".*"
+      oneOf:
+      - properties:
+          either: {}
+        required:
+        - "either"
+      - properties:
+          or: {}
+        required:
+        - "or"
       required:
       - "stringProperty"

crd-generator/src/test/resources/io/strimzi/crdgenerator/simpleTestHelmMetadata.yaml

@@ -420,5 +420,14 @@ spec:
         stringProperty:
           type: "string"
           pattern: ".*"
+      oneOf:
+      - properties:
+          either: {}
+        required:
+        - "either"
+      - properties:
+          or: {}
+        required:
+        - "or"
       required:
       - "stringProperty"