.NET 8– Upgrade warnings

As our policy is to keep our .NET applications on the latest LTS version, we started to upgrade our application portfolio to .NET 8. Changing the Target Framework Moniker and updating the ASP.NET Core NuGet packages was sufficient to get the upgrade done. However the upgrade also triggered some warnings and because we had ‘Treat warnings as errors’ enabled in Visual Studio, our applications refused to compile.

SYSLIB0051

The first warning we got was SYSLIB0051:

Severity	Code	Description	Project	File	Line	Suppression State
Warning	SYSLIB0051	'Exception.Exception(SerializationInfo, StreamingContext)' is obsolete: 'This API supports obsolete formatter-based serialization. It should not be called or extended by application code.'	SOFACore	C:\source\repos\SOFACore\Configuration\ConfigurationException.cs	20	Active

For every exception class we had a specific constructor that was only used for serialization purposes. As this constructor was intended to support remoting and remoting is not supported in .NET Core it doesn’t make sense to keep this constructor.

We got rid of this warning by removing all the serialization constructors for our Exception classes.

SYSLIB0049

A second (less frequent) warning we got SYSLIB0049:

Severity	Code	Description	Project	File	Line	Suppression State
Warning	SYSLIB0049	'JsonSerializerOptions.AddContext<TContext>()' is obsolete: 'JsonSerializerOptions.AddContext is obsolete. To register a JsonSerializerContext, use either the TypeInfoResolver or TypeInfoResolverChain properties.'	eShopExample	C:\source\repos\SOFACore\Example\eShopExample\Startup.cs	55	Active

In our code we use a custom JsonContext to configure how serialization should be handled by System.Text.Json:

The JsonSerializerOptions.AddContext<TContext>() method was introduced in .NET 6 as a means to associate JsonSerializerOptions instances with a specified JsonSerializerContext type. This method was superseded in .NET 7 with the introduction of contract customization and the TypeInfoResolver property.

As the JsonSerializerContext type implements the ITypeInfoResolver interface , we can easily get rid of this warn by updating our code like this:

In the code above the JsonContext class is our own implemented JsonSerializerContext:

.NET 8–Keyed/Named Services

A feature that a lot of IoC container libraries support but that was missing in the default DI container provided by Microsoft is the support for Keyed or Named Services. This feature allows you to register the same type multiple times using different names, allowing you to resolve a specific instance based on the circumstances. Although there is some controversy if supporting this feature is a good idea or not, it certainly can be handy. To support this feature a new interface IKeyedServiceProvider got introduced in .NET 8 providing 2 new methods on our ServiceProvider instance: object? GetKeyedService(Type serviceType, object? serviceKey); object GetRequiredKeyedService(Type serviceType, object? serviceKey); To use it, we need to register our service using one of the new extension methods: Resolving the service can be done either through the FromKeyedServices attribute: or by injecting the IKeyedServiceProvider interface and calling the GetRequiredKeyedServic...

Azure DevOps/ GitHub emoji

I’m really bad at remembering emoji’s. So here is cheat sheet with all emoji’s that can be used in tools that support the github emoji markdown markup: All credits go to rcaviers who created this list.

Kubernetes–Limit your environmental impact

Reducing the carbon footprint and CO2 emission of our (cloud) workloads, is a responsibility of all of us. If you are running a Kubernetes cluster, have a look at Kube-Green . kube-green is a simple Kubernetes operator that automatically shuts down (some of) your pods when you don't need them. A single pod produces about 11 Kg CO2eq per year( here the calculation). Reason enough to give it a try! Installing kube-green in your cluster The easiest way to install the operator in your cluster is through kubectl. We first need to install a cert-manager: kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/v1.14.5/cert-manager.yaml Remark: Wait a minute before you continue as it can take some time before the cert-manager is up & running inside your cluster. Now we can install the kube-green operator: kubectl apply -f https://github.com/kube-green/kube-green/releases/latest/download/kube-green.yaml Now in the namespace where we want t...

The art of simplicity

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