Middleware in .Net Core

Middleware is an software used to handle web request pipeline. 

Describe in simple term means it's organize the request and response using delegates and pipeline.

It is an decision maker to pass the next request to particular component.

Example:

3-tier Architecture (API, Business Layer, Data Layer)

we will receive n-number request at the time middleware anonymously  handle the request in pipeline to execute API --> Business Layer --> Data Layer and response vise versa.

Middleware Roles and Responsibility

    1.Chooses whether to pass the request to the next component in the pipeline.

    2.Can perform work before and after the next component in the pipeline.

Request delegates are used to build the request pipeline. The request delegates handle each HTTP request.

Request delegates are configured using Run, Map, and Use extension methods. An individual request delegate can be specified in-line as an anonymous method (called in-line middleware), or it can be defined in a reusable class. These reusable classes and in-line anonymous methods are middleware, also called middleware components. Each middleware component in the request pipeline is responsible for invoking the next component in the pipeline or short-circuiting the pipeline. When a middleware short-circuits, it's called a terminal middleware because it prevents further middleware from processing the request.

Built-in middleware

Middleware	Description
HTTP Method Override	Allows an incoming POST request to override the method.
HTTPS Redirection	Redirect all HTTP requests to HTTPS.
HTTP Strict Transport Security (HSTS)	Security enhancement middleware that adds a special response header.