I have one custom middleware which i have to configured like this way if we disable it from backend then that middleware should detach from request pipeline and if i enable then it should i again attached to request pipeline but during this process do i have to restart or recycle application pool on server? check below example.

 class Startup{

 public void Configure(IApplicationBuilder app)
        {
            if(isCustomMiddlewareEnable){
              app.Custommiddleware()
            }
}
    }

CodePudding user response：

In short - yes, because Configure() as well as ConfigureServices() are called once during application startup. If the value behind isCustomMiddlewareEnable changes, i.e. you change a key's value in a configuration file with file reload enabled, that will still not affect your application behavior, having that configured as shown in question.

What you are looking for is a runtime evaluated if statement that redirects the request pipeline through a middleware if the condition is met.

app.UseWhen(
    context => context.Request.Method == HttpMethod.Post.Method, 
    builder => builder.Custommiddleware());

Alternatively, you can always go into the middleware, but execute your custom logic inside only if the condition is met:

public class CustomMiddleware
{
    private readonly RequestDelegate _next;

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

    public async Task InvokeAsync(HttpContext context, IOptions<CustomMiddlewareOptions> customOptions)
    {
        if (customOptions.Value.IsEnabled)
        {
            // Do some custom work.
        }

        await _next(context);
    }
}