Tag Archives: dnvm

Getting Started with ASP.Net 5 Nightly Builds on Windows

ASP.Net 5 is more than an update to ASP.Net, it is a dramatic rethinking of the .Net web stack. By dropping some of the baggage that has been with the framework since classic ASP, Microsoft has been able to greatly reduce the footprint of an ASP.Net application and created a more modular runtime that can be deployed to Windows, Mac, and Linux.

If you’d like to read a more complete breakdown of new features, Scott Guthrie’s excellent post announcing ASP.Net 5 is a good starting place.

As of April 2015, ASP.Net 5 is still in the beta. The easiest way to use it is to install the latest Visual Studio 2015 Community Technology Preview. But if you want to get features as the come available the best option is to install the new cross platform command line tools. These are the instructions for installing the latest ASP.Net tooling on Windows.

Installing dnvm

Because Visual Studio doesn’t run on Mac or Linux, a new set of tools needed to be created to use ASP.Net on those platforms. The ASP.Net team have been building a set of command line applications that lets users build ASP.Net projects with any editor.

ASP.Net 5 includes a new execution environment is called DNX. DNX bootstraps and runs your application, however it is not the CLR itself.

To install DNX you will need DNVM, the Dot Net Version Manager. You can download DNVM from the aspnet/home GitHub repo. This repo contains tools and samples to get you started, though some of the instructions don’t necessarily reflect the latest rapidly changes to the framework.

You will install DNVM by running the following in a command prompt.

@powershell -NoProfile -ExecutionPolicy unrestricted -Command "&{$Branch='dev';iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/aspnet/Home/dev/dnvminstall.ps1'))}"

This script will create a new .dnx directory under your %USERPROFILE%. It will contain a bin directory with the dnvm command.

Note: Originally the new ASP.Net runtime was code-named Project-K, so you may see references to tools that begin with the letter k (k, kvm, kpm). Those tools have been replaced by their DNX counterparts.

Adding DNX Nightly Builds NuGet Feed

You now have DNVM installed, but if you can’t yet install the latest nightly builds. The DNX is delivered as NuGet packages, and the nightly builds are served from a custom NuGet feed, https://www.myget.org/F/aspnetvnext/api/v2/. To add this feed to NuGet open %AppData%/NuGet/NuGet.config and change the contents to the following.

<?xml version="1.0" encoding="utf-8"?>
    <add key="AspNetVNext" value="https://www.myget.org/F/aspnetvnext/api/v2/" />
    <add key="nuget.org" value="https://www.nuget.org/api/v2/" />
  <disabledPackageSources />
    <add key="nuget.org" value="https://www.nuget.org/api/v2/" />

Installing the .Net Execution Environment (DNX)

Now that you have DNVM and you’ve configured NuGet you can install the DNX. To install the latest version open PowerShell or a command prompt and run:

dnvm upgrade

This will install a new runtime under %USERPROFILE%/.dnx/runtimes/ and add the bin directory of the new runtime to your PATH. The bin directory has two important commands

  • dnx – used run a .Net application under the DNX
  • dnu – Dot Net Utility used to perform tasks like building, installing packages, and more

Running a Sample Project

You should now be ready to run a sample project. New project scaffolding isn’t functional with DNX at the moment, so the best way to run an ASP.Net 5 project is to clone an existing project. The aspnet/home repo mentioned above has sample projects using the latest runtime, just make sure you’re looking in the dev branch.

The critial component to look for is the supported frameworks in the project.json file. The supported frameworks should be dnx451 and dnxcore50.

"frameworks": {
"dnx451": { },
"dnxcore50": { }

If you see aspnet50 or aspnetcore50 you’re looking at an old version from before the DNX rename.

So, clone the dev branch of the aspnet/home repo.Then, at the command line move to the HelloMvc folder and run the following command.

dnu restore

This is equivalent to restoring packages for a solution with NuGet in Visual Studio. In fact, under the covers it’s simply using the newest version of NuGet!

Now you’re ready to run the project. Still at the root of the HelloMvc folder simply run dnx . web and your project will begin running at http://localhost:5001 (as defined in the project.json).

D:\dev\aspnet-home\samples\HelloMvc> dnx . web

The output for the web command is pretty underwhelming. If you’d like to see a little more output upgrade Microsoft.AspNet.Server.WebListener in project.json to 1.0.0-beta5* and you’ll see something like the following.

D:\dev\uavdb\src> dnx . web
info : [Microsoft.Framework.DependencyInjection.DataProtectionServices] Userprofile is available. Using 'C:\Users\pnewhook\AppData\Local\ASP.NET\DataProtec
ion-Keys' as key repository and Windows DPAPI to encrypt keys at rest.
info : [Microsoft.Net.Http.Server.WebListener] Start
info : [Microsoft.Net.Http.Server.WebListener] Listening on prefix: http://lcalhost:5001/


It’s an exciting time to be an .Net developer. The latest version of ASP.Net framework is open source and it’s possible to follow the team’s development live. While you could install the latest Visual Studio 2015 CTP, you won’t be able to try new features as they’re released. There will likely be a big announcement at Build on April 29th. The command line tools are probably the way to go for now, and they have the added bonus of working cross platform.

There are three commands you’ll run into:

  • dnvm – the .Net Version Mananger for installing the DNX
  • dnu – the .Net Utility for managing projects and packages
  • dnx – the Execution Environment executable for running your projects

A core tenent of the DNX is to make everything a NuGet package. While the framework is under development, and potentially beyond, nightly builds are served through a MyGet feed that needs to be configured in your NuGet install.

After you’ve taken these steps you’ll be ready to experiment with ASP.Net 5 feature hot off the press.