Skip to main content

ASP.NET Core - ASPNETCORE_FORWARDEDHEADERS_ENABLED environment variable

Although you can directly use Kestrel to act as an “Edge” server, a typical approach is to host it behind a reverse proxy(NGINX, Azure Application Gateway, …). If you are running your ASP.NET Core application inside Kubernetes, this is typically handled through an ingress. This ingress defines the hostname and paths your application should be exposed at. An ingress controller will map this configuration to an implementation. This can be a direct mapping to some infrastructure configuration such as a load balancer(e.g. Azure Application Gateway) or a reverse proxy running inside the cluster.

When your app is running behind a reverse proxy, it is important to configure your application to use the “forwarded headers” added by the reverse proxy. This can be done through the Forwarded Headers middleware.

Starting from .NET Core 3.0 you can take a different approach through the usage of the ASPNETCORE_FORWARDEDHEADERS_ENABLED environment variable. . Turning on the Forwarded Headers Middleware is as simple as setting this environment variable to ‘true’.

Important to notice is that you should only take this approach when you’re:
A. Positive you're behind a trusted proxy
B. AND the deployment environment is unpredictable such that you can't specify KnownProxies or KnownNetworks. A cloud provider is such an environment.

Otherwise you should configure ForwardedHeadersOptions as shown above and set KnownProxies/Networks.

Labels:

Popular posts from this blog

.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...
Read more

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.
Read more

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...
Read more