feat(crd generation): Throw an error on unsupported crd type.

This closes #80.

Author: Christoph Bühler

src/KubeOps/Operator/Entities/Extensions/EntityToCrdExtensions.cs

@@ -6,6 +6,7 @@
 using k8s;
 using k8s.Models;
 using KubeOps.Operator.Entities.Annotations;
+using KubeOps.Operator.Errors;
 using Namotion.Reflection;
 
 namespace KubeOps.Operator.Entities.Extensions
@@ -55,7 +56,6 @@ internal static V1CustomResourceDefinition CreateCrd(this Type entityType)
             var version = new V1CustomResourceDefinitionVersion();
             spec.Versions = new[] { version };
 
-            // TODO: versions?
             version.Name = entityDefinition.Version;
             version.Served = true;
             version.Storage = true;
@@ -72,7 +72,18 @@ internal static V1CustomResourceDefinition CreateCrd(this Type entityType)
 
         private static V1JSONSchemaProps MapProperty(PropertyInfo info)
         {
-            var props = MapType(info.PropertyType);
+            V1JSONSchemaProps props;
+            try
+            {
+                props = MapType(info.PropertyType);
+            }
+            catch (Exception ex)
+            {
+                throw new CrdConversionException(
+                    $@"During conversion of the property ""{info.Name}"" with type ""{info.PropertyType.Name}"", an error occured.",
+                    ex);
+            }
+
             var contextual = info.ToContextualProperty();
 
             // Check for nullability and nullable types
@@ -186,13 +197,16 @@ private static V1JSONSchemaProps MapType(Type type)
                      (typeof(IDictionary).IsAssignableFrom(type) ||
                       (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(IDictionary<,>)) ||
                       (type.IsGenericType &&
-                       type.GetGenericArguments().FirstOrDefault()?.IsGenericType == true && type.GetGenericArguments().FirstOrDefault()?.GetGenericTypeDefinition() ==
+                       type.GetGenericArguments().FirstOrDefault()?.IsGenericType == true &&
+                       type.GetGenericArguments().FirstOrDefault()?.GetGenericTypeDefinition() ==
                        typeof(KeyValuePair<,>))))
             {
                 props.Type = Object;
                 props.XKubernetesPreserveUnknownFields = true;
             }
-            else if (!IsSimpleType(type) && type.IsGenericType && typeof(IEnumerable<>).IsAssignableFrom(type.GetGenericTypeDefinition()))
+            else if (!IsSimpleType(type) &&
+                     type.IsGenericType &&
+                     typeof(IEnumerable<>).IsAssignableFrom(type.GetGenericTypeDefinition()))
             {
                 props.Type = Array;
                 props.Items = MapType(type.GetGenericArguments()[0]);
@@ -248,6 +262,10 @@ private static V1JSONSchemaProps MapType(Type type)
                 props.Type = String;
                 props.EnumProperty = new List<object>(Enum.GetNames(Nullable.GetUnderlyingType(type)!));
             }
+            else
+            {
+                throw new CrdPropertyTypeException();
+            }
 
             return props;
         }

src/KubeOps/Operator/Errors/CrdConversionException.cs

@@ -0,0 +1,21 @@
+using System;
+
+namespace KubeOps.Operator.Errors
+{
+    internal class CrdConversionException : Exception
+    {
+        public CrdConversionException()
+        {
+        }
+
+        public CrdConversionException(string message)
+            : base(message)
+        {
+        }
+
+        public CrdConversionException(string message, Exception innerException)
+            : base(message, innerException)
+        {
+        }
+    }
+}

src/KubeOps/Operator/Errors/CrdPropertyTypeException.cs

@@ -0,0 +1,22 @@
+using System;
+
+namespace KubeOps.Operator.Errors
+{
+    internal class CrdPropertyTypeException : Exception
+    {
+        public CrdPropertyTypeException()
+            : this("The given property has an invalid type.")
+        {
+        }
+
+        public CrdPropertyTypeException(string message)
+            : base(message)
+        {
+        }
+
+        public CrdPropertyTypeException(string message, Exception innerException)
+            : base(message, innerException)
+        {
+        }
+    }
+}

tests/KubeOps.Test/Operator/Entities/CrdGeneration.Test.cs

@@ -5,6 +5,7 @@
 using k8s.Models;
 using KubeOps.Operator.Commands.Generators;
 using KubeOps.Operator.Entities.Extensions;
+using KubeOps.Operator.Errors;
 using KubeOps.Test.TestEntities;
 using Xunit;
 
@@ -327,5 +328,12 @@ public void Should_Map_Embedded_Resources()
             specProperties.Properties["kubernetesObject"].XKubernetesPreserveUnknownFields.Should().BeTrue();
             specProperties.Properties["kubernetesObject"].XKubernetesEmbeddedResource.Should().BeTrue();
         }
+
+        [Fact]
+        public void Should_Throw_On_Not_Supported_Type()
+        {
+            var ex = Assert.Throws<CrdConversionException>(() => typeof(TestInvalidEntity).CreateCrd());
+            ex.InnerException.Should().BeOfType<CrdPropertyTypeException>();
+        }
     }
 }

tests/KubeOps.Test/TestEntities/TestInvalidEntity.cs

@@ -0,0 +1,15 @@
+using k8s.Models;
+using KubeOps.Operator.Entities;
+using KubeOps.Operator.Entities.Annotations;
+
+namespace KubeOps.Test.TestEntities
+{
+    [IgnoreEntity]
+    [KubernetesEntity(Group = "kubeops.test.dev", ApiVersion = "V1")]
+    public class TestInvalidEntity : CustomKubernetesEntity
+    {
+        public ulong Unsupported { get; set; }
+
+        public ulong? NullableUnsupported { get; set; }
+    }
+}