Incremental ASP.NET to ASP.NET Core MigrationThis is an Experimental project, things are subject to change, and not formally supported. The goal of this extension is to assist in Incremental migration from ASP.NET Framework to ASP.NET Core. This project relies upon System.WebAdapters. Migrating an application from ASP.NET Framework to ASP.NET Core is a non-trivial action for the majority of large applications. These applications have often grown organically over time, incorporating new technologies as they come and are often composed of many legacy decisions. The aim of this repo is to provide tools and support for migrating these large applications with as little change as possible to ASP.NET Core. One of the larger challenges is the pervasive use of System.Web.HttpContext throughout a code base to access information about a request or update a response. Until now, in order to move forward, a large scale rewrite was required to remove this dependency. Now, the adapters in this repo provide a set of runtime helpers to access the types your code is expecting but in a way that will work on ASP.NET Core with little change. A complete migration may take a while depending on the size of the application. In order to continue deploying an application to production while working on migrating, the best pattern is to follow is the Strangler Fig pattern. This pattern allows for continual development on the old system with an incremental approach to moving forward. This document will describe how to apply that pattern to an ASP.NET app migrating towards ASP.NET Core. To get started right click on the project in the Solution Explorer and select Migrate project
This will open the Migrations configuraiton page. From here, click Start migration.
From here it will walk you through either creating a new ASP.NET Core project, or selecting an existing ASP.NET Core project. After you have completed this wizard, the ASP.NET framework project will be configured such that any requests which are not handled by the ASP.NET framework project will be routed to the ASP.NET Core project. When running the web app, you should launch both the ASP.NET framework project as well as the ASP.NET Core project. In most cases after going through Migrate project these projects will be configured to run in Visual Studio. If you need to configure your startup projects, you can learn more about that at https://docs.microsoft.com/en-us/visualstudio/ide/how-to-set-multiple-startup-projects?view=vs-2022. For more info on how to migrate your project see: If you run into any issues, or have suggestions for improvements, please let us know with the built-in support in Visual Studio to Report a Problem. |
