fix: Add support for System.Object in CRDs (#857)

Co-authored-by: Razvan Grama <[email protected]>
Co-authored-by: Christoph Bühler <[email protected]>

Author: 3 people

src/KubeOps.Transpiler/Crds.cs

@@ -300,6 +300,11 @@ private static V1JSONSchemaProps Map(this MetadataLoadContext context, Type type
             return new V1JSONSchemaProps { Type = String };
         }
 
+        if (type.FullName == "System.Object")
+        {
+            return new V1JSONSchemaProps { Type = Object, XKubernetesPreserveUnknownFields = true };
+        }
+
         if (type.Name == typeof(Nullable<>).Name && type.GenericTypeArguments.Length == 1)
         {
             var props = context.Map(type.GenericTypeArguments[0]);
@@ -345,7 +350,29 @@ private static V1JSONSchemaProps Map(this MetadataLoadContext context, Type type
             return context.MapObjectType(type);
         }
 
-        return type.BaseType?.FullName switch
+        static Type GetRootBaseType(Type type)
+        {
+            var current = type;
+            while (current.BaseType != null)
+            {
+                var baseName = current.BaseType.FullName;
+
+                if (baseName == "System.Object" ||
+                    baseName == "System.ValueType" ||
+                    baseName == "System.Enum")
+                {
+                    return current.BaseType; // This is the root base we're after
+                }
+
+                current = current.BaseType;
+            }
+
+            return current; // In case it's already System.Object
+        }
+
+        var rootBase = GetRootBaseType(type);
+
+        return rootBase.FullName switch
         {
             "System.Object" => context.MapObjectType(type),
             "System.ValueType" => context.MapValueType(type),

test/KubeOps.Transpiler.Test/Crds.Mlc.Test.cs

@@ -350,6 +350,15 @@ public void Should_Set_Preserve_Unknown_Fields_On_Classes()
         specProperties.XKubernetesPreserveUnknownFields.Should().BeTrue();
     }
 
+    [Fact]
+    public void Should_Set_Preserve_Unknown_Fields_On_System_Object()
+    {
+        var crd = _mlc.Transpile(typeof(EntityWithSystemObject));
+
+        var specProperties = crd.Spec.Versions.First().Schema.OpenAPIV3Schema.Properties["spec"].Properties["obj"];
+        specProperties.XKubernetesPreserveUnknownFields.Should().BeTrue();
+    }
+
     [Fact]
     public void Should_Set_Preserve_Unknown_Fields_On_ObjectLists()
     {
@@ -713,6 +722,15 @@ private class UnknownFieldsEntity : CustomKubernetesEntity<UnknownFieldsEntity.E
         public class EntitySpec;
     }
 
+    [KubernetesEntity(Group = "testing.dev", ApiVersion = "v1", Kind = "TestEntity")]
+    private class EntityWithSystemObject : CustomKubernetesEntity<EntityWithSystemObject.EntitySpec>
+    {
+        public class EntitySpec
+        {
+            public object Obj { get; set; } = null!;
+        }
+    }
+
     [KubernetesEntity(Group = "testing.dev", ApiVersion = "v1", Kind = "TestEntity")]
     private class UnknownFieldsListEntity : CustomKubernetesEntity<UnknownFieldsListEntity.EntitySpec>
     {