Generating CRDs without a current Kubernetes context?

[jefflill]

This looks like a really cool library. We're looking at this for implementing operators for a nascent Kubernetes distribution: neonKUBE

One problem I'm having is actually building an operator that generates CRDs. The issue appears to be with dependency injection trying to construct a KubernetesClient instance when I don't have a current Kubernetes context specified in my .kube/config file.

I replicated this with your KubeOps.TestOperator by executing (without a current Kubernetes context) in the debugger with this command line:

generator crds --out config\crds --format Yaml

here's the exception:

Unhandled exception. System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> k8s.Exceptions.KubeConfigException: Cannot infer server host url either from context or masterUrl
   at k8s.KubernetesClientConfiguration.GetKubernetesClientConfiguration(String currentContext, String masterUrl, K8SConfiguration k8SConfig)
   at k8s.KubernetesClientConfiguration.BuildConfigFromConfigObject(K8SConfiguration k8SConfig, String currentContext, String masterUrl)
   at k8s.KubernetesClientConfiguration.BuildDefaultConfig()
   at DotnetKubernetesClient.KubernetesClient..ctor()
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, RuntimeResolverContext context)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSiteMain(ServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitDisposeCache(ServiceCallSite transientCallSite, RuntimeResolverContext context)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(ServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.Resolve(ServiceCallSite callSite, ServiceProviderEngineScope scope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass1_0.<RealizeService>b__0(ServiceProviderEngineScope scope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType)
   at McMaster.Extensions.CommandLineUtils.CommandLineApplication.ServiceProvider.GetService(Type serviceType)
   at McMaster.Extensions.CommandLineUtils.CommandLineApplication.System.IServiceProvider.GetService(Type serviceType)
   at McMaster.Extensions.CommandLineUtils.Conventions.ConstructorInjectionConvention.FindMatchedConstructor[TModel](ConstructorInfo[] constructors, IServiceProvider services, Boolean throwIfNoParameterTypeRegistered)
   at McMaster.Extensions.CommandLineUtils.Conventions.ConstructorInjectionConvention.ApplyImpl[TModel](ConventionContext context)
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters)
   at McMaster.Extensions.CommandLineUtils.Conventions.ConstructorInjectionConvention.Apply(ConventionContext context)
   at McMaster.Extensions.CommandLineUtils.CommandLineApplication.Builder.McMaster.Extensions.CommandLineUtils.Conventions.IConventionBuilder.AddConvention(IConvention convention)
   at McMaster.Extensions.CommandLineUtils.ConventionBuilderExtensions.UseConstructorInjection(IConventionBuilder builder, IServiceProvider additionalServices)
   at KubeOps.Operator.HostExtensions.RunOperatorAsync(IHost host, String[] args) in C:\Temp\dotnet-operator-sdk\src\KubeOps\Operator\HostExtensions.cs:line 24
   at Program.<Main>$(String[] args) in C:\Temp\dotnet-operator-sdk\tests\KubeOps.TestOperator\Program.cs:line 10
   at Program.<Main>(String[] args)

It seems to me that constructing a KubernetesClient instance isn't really necessary for generating the CRDs. Is there a way to avoid this?

[buehler]

Hey @jefflill

Sadly this is bug.

[buehler]

Just created an issue

[buehler]

Hey @jefflill, this should be fixed with cde5ef8

[jefflill]

I've worked around this by creating a temporary kubeconfig file with a current context referencing an non-existent cluster and pointing the KUBECONFIG environment variable to this file while the generator commands are being handled by KubeOps.

Here's what this looks like: (search for HandleGeneratorCommand):

https://github.com/nforgeio/neonKUBE/blob/master/Lib/Neon.Kube.Operator/OperatorHelper.cs

[buehler]

This works as well :-)
But with the latest version, this issue is fixed ;-)

[jefflill]

THANKS!

…

On Sun, Jan 2, 2022 at 4:12 AM Christoph Bühler ***@***.***> wrote: Hey @jefflill <https://github.com/jefflill>, this should be fixed with cde5ef8 <cde5ef8> — Reply to this email directly, view it on GitHub <#343 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABFOLD4Q3RT34BYWN2D5P2LUUA6LVANCNFSM5K5FWR5Q> . You are receiving this because you were mentioned.Message ID: ***@***.*** com>