ASP.NET 5 Pre-RC 2 On Linux – Part II

So now it is time to improve my development experience on this fresh Ubuntu VM. First step is to get a better code editor, and I select Visual Studio Code (VSCode) for the job.

To get VSCode visit:

https://code.visualstudio.com

I downloaded the .zip and then created a new folder under ‘Home’ called ‘Apps’

Using file explorer (Nautilus) I moved the zip from Downloads to Apps and extracted it.

capture_2

Then per the instructions, I created a link using the command

sudo ln -s ~/Apps/VSCode-linux-x64/Code /usr/local/bin/code

This allows us to start VSCode in the current folder by typing

code . 

in terminal.

Also, to create the UI shortcuts I browsed to the Code executable using Nautilus, right clicked Code, selected ‘make link’ and dragged it to the desktop and rename it to VSCode.

capture_3

I started code by clicking the shortcut and since it will be commonly used,
I right clicked the icon on Ubuntu’s side toolbar (Launcher) and selected “Lock To Launcher”.

All seemed fine but then I noticed a message in the lower right corner of VSCode, ‘failed to start OmniSharp’. Clicking on that reveals the message

Capture4

VSCode uses Omnisharp for intellisense so this is a problem.

In the end the solution for me was to install the latest development version of Mono (4.2.1), using the command

sudo apt-get install mono-devel

ASP.NET 5 Pre-RC 2 On Linux – Part I

Now that I’ve dabbled with running RC1 (Release Candidate 1) on Linux, time to start using the pre-RC2 bits as they use the new ‘dotnet’ CLI (Command Line Interface).

I started by creating a new Ubuntu VM, just like I did before for RC1, so there would be no cross-contamination between dnvm/dnu/dnx and dotnet.

I then went to the dotnet CLI repository on github https://github.com/dotnet/cli, and since I am using Ubuntu I downloaded the Debian package per the instructions. The heavy lifting of installing was then handled by the Ubuntu Software Center.

Capture

Per the instructions, in Terminal I then executed

export DOTNET_HOME=/usr/share/dotnet/

I then created a directory for my project with the following commands

cd ~
cd Documents
mkdir Code
cd Code
mkdir ConsoleApp1
cd ConsoleApp1

I then executed

dotnet new

This creates a new empty console project, which conveniently creates a program.cs file that emits “Hello World” via the console. The files are as below

Program.cs:

using System;

namespace ConsoleApplication
{
    public class Program
    {
        public static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");
        }
    }
}

project.json:

{
    "version": "1.0.0-*",
    "compilationOptions": {
        "emitEntryPoint": true
    },

    "dependencies": {
        "NETStandard.Library": "1.0.0-rc2-23616"
    },

    "frameworks": {
        "dnxcore50": { }
    }
}

Note: Unlike in RC1, the “emitEntryPoint” compilation option is a requirement!

Now that we have a project.json file and a Program.cs file, we need to restore, just like we did with dnu, but instead we just issue the dotnet restore command.

Note that since we are using post RC1 tools, we need to set the source for our packages using the -s parameter to be the dotnet-core repository on MyGet, rather than the using the default NuGet repository. This most likely will not be necessary with RC2 and above.

dotnet restore -s https://myget.org/f/dotnet-core

Now we can run the program by executing

dotnet run

the result?

failed to locate CLR files at /usr/share/dotnet/runtime/coreclr

I did a little investigating and the issue is the files are being installed under /usr/share/dotnet-dev/, not /usr/share/dotnet/. I reported this as an issue on github.

I then set the DOTNET_HOME variable like so

export DOTNET_HOME=/usr/share/dotnet-dev/

I then tried the program again

dotnet run
Hello World!

ASP.NET 5 RC1 On Linux – INFO

Before I reset, I decided to lay out some basic info about ASP.NET 5

The current released (at present RC1) bits can be retrieved from

https://get.asp.net

Any bugs/issue or qualms should be posted to the appropriate repository on Github
https://github.com/aspnet

Recordings of the ASP.NET team standups can be found at

https://live.asp.net

The documentation (in progress) can be found at

https://docs.asp.net

Note any docs with a wrench icon has not been started yet.

There is also a freely available Microsoft Virtual Academy course available:

https://mva.microsoft.com/en-US/training-courses/introduction-to-asp-net-5-13786

ASP.NET 5 RC1 On Linux – Intermission

Well, in my last post I mentioned a Powershell/DNX case sensitivity issue related to commands. I logged this as an issue over on GitHub and was told that DNX,DNU and DNVM will be retired in RC2 in favor of a unified “dotnet” CLI (ETA February 2016). I had heard about these being possibly being replaced a few months ago at a regional .NET event, and also Scott Hanselman mentioned the new CLI last week on his blog

It’s possible to start try out some of these bits now so I will try re-starting with that in a future post (soon!).

ASP.NET 5 RC1 On Linux – Part IV – First App Analysis

Looking at the project.json from my last post

We see the following

{
  "version": "1.0.0-*",
  "description": "ConsoleApp1 Console Application",
  "authors": [ "knarfalingus" ],
  "tags": [ "hello", "world" ],
  "projectUrl": "https://www.knarfalingus.com",
  "licenseUrl": "https://opensource.org/licenses/MIT",

  "compilationOptions": {
    "emitEntryPoint": true
  },

  "dependencies": {
  },

  "commands": {
    "ConsoleApp1": "ConsoleApp1"
  },

  "frameworks": {
    "dnxcore50": {
      "dependencies": {
       "Microsoft.CSharp": "4.0.1-beta-23516",
       "System.Console": "4.0.0-beta-23516",
      }
    }
  }
}

To simplify, we can actually remove the following

  "compilationOptions": {
    "emitEntryPoint": true
  }

This wasn’t required as the runtime will find the static Main() method.

Also we can remove the metadata, authors, projectUrl and licenseUrl etc. I added those arbitrarily anyway.

What is interesting is the commands

  "commands": {
    "ConsoleApp1”: “ConsoleApp1”
  }

The above is typical of what Visual Studio 2015 would create. The name “ConsoleApp1” doesn’t have to match the application/namespace, for example the following works just as well.

  "commands": {
    “xyz”: "ConsoleApp1”
  }

This can be explicitly run by executing

dnx xyz

The surprising part I found when trying this on Windows was, the value “ConsoleApp1” refers to the folder the app is in, not the namespace or application title. For example with this project.json

{
  "version": "1.0.0-*",

  "dependencies": {
  },

  "commands": {
    “xyz”: "ConsoleApp1"
  },

  "frameworks": {
    "dnxcore50": {
      "dependencies": {
        "Microsoft.CSharp": "4.0.1-beta-23516",
        "System.Console": "4.0.0-beta-23516",
      }
    }
  }
}

And the two files, project.json and Program.cs in a ConsoleApp1 directory, if I change into the directory from the parent directory using cd ConsoleApp1, dnx xyz works but if I do cd consoleapp1, in Powershell it doesn’t!, Powershell introduces case into the folder name see below. This doesn’t happen with the standard console.

Powershell can introduce case sensitivity issues when combined with commands

I am not sure if this is a bug or not due to the fact that ASP.NET is targeting systems with case sensitive file systems whereas in Windows the file system is not case sensitive (by default).