Error while trying to create HorizontalPodAutoscaler with DynamicResourceClient

I couldn’t find a specific HPA namespace for handling APIs, so I noticed it was possible to make generic calls with DynamicResourceClient.

But, during my tests, I received the following error when I tried to create a HPA, although I was filling the ‘Namespace’ property, inside the Metadata object: Required template parameter 'namespace' is not defined.

Stack Trace

   at HTTPlease.Core.Templates.TemplateEvaluationContext.get_Item(String parameterName, Boolean isOptional)
   at HTTPlease.Core.Templates.ParameterizedUriSegment.GetValue(ITemplateEvaluationContext evaluationContext)
   at HTTPlease.UriTemplate.Populate(Uri baseUri, IDictionary`2 templateParameters)
   at HTTPlease.HttpRequest.BuildRequestMessage(HttpMethod httpMethod, HttpContent body, Uri baseUri)
   at HTTPlease.FormatterRequestExtensions.BuildRequestMessage(HttpRequest request, HttpMethod httpMethod, Object bodyContent, String mediaType, Encoding encoding, Uri baseUri)
   at HTTPlease.FormatterRequestExtensions.BuildRequestMessage(HttpRequest request, HttpMethod httpMethod, Object bodyContent, String mediaType, Uri baseUri)
   at HTTPlease.FormatterClientExtensions.<PostAsync>d__0.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
   at HTTPlease.FormatterResponseExtensions.<ReadContentAsAsync>d__7`2.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at KubeClient.ResourceClients.HttpExtensions.<ReadContentAsObjectV1Async>d__6`1.MoveNext() in C:\Work\dotnet-kube-client\src\KubeClient\ResourceClients\HttpExtensions.cs:line 286
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at KubeClient.ResourceClients.DynamicResourceClient.<Create>d__9`1.MoveNext() in C:\Work\dotnet-kube-client\src\KubeClient\ResourceClients\DynamicResourceClient.cs:line 320

The method I called to create the HPA:

__kubeApiClient__.Dynamic().Create(_hpa, true);

And this is how the object hpa is being created:

HorizontalPodAutoscalerV1 hpa = new HorizontalPodAutoscalerV1()
{
	Metadata = new ObjectMetaV1()
	{
		Name = "hpa_name",
		Namespace = "hpa_namespace",
	},
	Spec = new HorizontalPodAutoscalerSpecV1()
	{
		MaxReplicas = 4,
		MinReplicas = 2,
		ScaleTargetRef = new CrossVersionObjectReferenceV1()
		{
			ApiVersion = "apps/v1",
			Kind = "Deployment",
			Name = "deployment_name"
		},
		TargetCPUUtilizationPercentage = 70
	}
};

By looking through DynamicResourceClient code, an annonymous object is created with a single property ‘Namespace’ - with a capital “N”

Path: src\KubeClient\ResourceClients\DynamicResourceClient.cs Method: Create Line: 314

request = request.WithTemplateParameters(new
{
	Namespace = resource.Metadata?.Namespace ?? KubeClient.DefaultNamespace
});

But, the url parameter is ‘namespace’, with a lower case “n”, as seen below: “apis/autoscaling/v1/namespaces/{namespace}/horizontalpodautoscalers”

I cloned the repository and changed the code metioned above to create an object with a property called ‘namespace’ (lower case “n”). After this change, no error was thrown and my HPA was created.

request = request.WithTemplateParameters(new
{
	@namespace = resource.Metadata?.Namespace ?? KubeClient.DefaultNamespace
});

“Patch”, “Get”, “ApplyYaml” and “Delete” methods from the same class also create the request with a lower case “n” property.

So I was wondering if I am doing something wrong. Is there something I am missing? Thanks in advance.

[tintoy]

Yep that’s a bug - nice catch 😃

I’ll get that sorted out tomorrow.

[diogoaraujo9]

Ok, pull request created.