How to log request and response metadata in ASP.NET Web API

Take advantage of a custom message handler to log request and response metadata in Web API for debugging, tracing, and inspection of the incoming and outgoing calls

How to log request and response metadata in ASP.NET Web API
Thinkstock

Like authentication, caching, and exception management, logging is a crosscutting concern – a function that affects the entire application – that should be centralized. We often log application data that may include the sequence of method calls or events, user actions, or even errors that may occur when the application executes. There are many logging frameworks you could take advantage of, but in this article we’ll focus on how we can log requests and responses in ASP.NET Web API.

Logging requests and responses in Web API is helpful in debugging, tracing, and inspection of the incoming and outgoing service calls. By logging all requests and responses in one place, detecting problems in any requests and responses becomes easy. In this post, we will create a custom message handler to monitor and log requests and responses in Web API. The message handler will be used to intercept calls and log all requests and responses centrally in one place.

Strategies to inject crosscutting concerns in Web API

There are multiple ways to inject logging and other crosscutting concerns in Web API. One way is to create a custom ApiController class, or a base class for all of our controllers, and then override the ExecuteAsync method. Another way is to use a custom action filter. However, both of these strategies have their limitations. In the former case, we would have to ensure that all of our controllers extend the custom base controller class. In the latter, we would have to ensure that the filter is applied on all of the controllers we use.

The best strategy in my opinion is to use a message handler because you write it only once and then register it in one place. Also, because the custom message handler will be called much earlier in the pipeline, i.e., even before the HttpControllerDispatcher, it is well suited to injecting crosscutting concerns. Incidentally, message handlers are classes that inherit the abstract HttpMessageHandler class. Hence, we will be taking advantage of a message handler to inject our custom logger in this post.

To continue reading this article register now

How to choose a low-code development platform