Register or remove middleware without deploying code-CodePudding

I have created a middleware which logs requests/response data in the database. I want this middleware to work only when I want to troubleshoot defect or unwanted exception. The middleware should not log rest of the time. I want a switch button which I can on or off on any controller without making any code changes and deployment.

Please suggests the ways to achieve the above.

CodePudding user response：

In Program.cs, you can add conditionally a middleware like :

var builder = WebApplication.CreateBuilder(args);
...
var app = builder.Build();
if (app.Configuration.Get<bool>("MiddlewareLog.Enable"))
{
    app.UseCustomeLoggerMiddleware();
}
...

To enable/disable the middleware, you only need to update the appsettings.json and restart the web api/app.

CodePudding user response：

A solution is to enable/disable the middleware from a global setting. Then the controller's action can modify this global setting to enable/disable the middleware.

public class LoggerMiddleware
{
    public static volatile bool Enable;

    private readonly RequestDelegate _next;

    public LoggerMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task InvokeAsync(HttpContext context)
    {
        if(Enable)
        {
            // Log
        }
        await _next(context);
    }
}

[Route("logger")]
public class LoggerController : ControllerBase
{
    [HttpGet]
    public void EnableOrDisable(bool enable)
    {
        LoggerMiddleware.Enable = enable;
    }
}

In the example, I use a static field, but it's possible to inject a singleton service in the middleware and the controller to share the setting.