Scott Hanselman

Writing and debugging Linux C++ applications from Visual Studio using the "Windows Subsystem for Linux"

April 3, '17 Comments [19] Posted in Linux | Open Source | Win10
Sponsored By

I've blogged about the "Windows Subsystem for Linux" (also known as "Bash on Ubuntu on Windows") many times before. Response to this Windows feature has been a little funny because folks try to:

  • Minimize it - "Oh, it's just Cygwin." (It's actually not, it's the actual Ubuntu elf binaries running on a layer that abstracts the Linux kernel.)
  • Design it - "So it's a docker container? A VM?" (Again, it's a whole subsystem. It does WAY more than you'd think, and it's FASTer than a VM.)

Here's a simple explanation from Andrew Pardoe:

1. The developer/user uses a bash shell.
2. The bash shell runs on an install of Ubuntu
3. The Ubuntu install runs on a Windows subsystem. This subsystem is designed to support Linux.

It's pretty cool. WSL has, frankly, kept me running Windows because I can run cmd, powershell, OR bash (or zsh or Fish). You can run vim, emacs, tmux, and run Javascript/node.js, Ruby, Python, C/C++, C# & F#, Rust, Go, and more. You can also now run sshd, MySQL, Apache, lighttpd as long as you know that when you close your last console the background services will shut down. Bash on Windows is for developers, not background server apps. And of course, you apt-get your way to glory.

Bash on Windows runs Ubuntu user-mode binaries provided by Canonical. This means the command-line utilities are the same as those that run within a native Ubuntu environment.

I wanted to write a Linux Console app in C++ using Visual Studio in Windows. Why? Why not? I like VS.

Setting up Visual Studio 2017 to compile and debug C++ apps on Linux

Then, from the bash shell make sure you have build-essential, gdb's server, and openssh's server:

$ sudo apt update
$ sudo apt install -y build-essential
$ sudo apt install -y gdbserver
$ sudo apt install -y openssh-server

Then open up /etc/ssh/sshd_config with vi (or nano) like

sudo nano /etc/ssh/sshd_config

and for simplicity's sake, set PasswordAuthentication to yes. Remember that it's not as big a security issue as you'd think as the SSHD daemon closes when your last console does, and because WSL's subsystem has to play well with Windows, it's privy to the Windows Firewall and all its existing rules, plus we're talking localhost also.

Now generate SSH keys and manually start the service:

$ sudo ssh-keygen -A
$ sudo service ssh start

Create a Linux app in Visual Studio (or open a Makefile app):

File | New Project | Cross Platform | Linux

Make sure you know your target (x64, x86, ARM):

Remote GDB Debugger options

In Visual Studio's Cross Platform Connection Manager you can control your SSH connections (and set up ones with private keys, if you like.)

Tools | Options | Cross Platfrom | Connection Manager

Boom. I'm writing C++ for Linux in Visual Studio on Windows...running, compiling and debugging on the local Linux Subsystem

I'm writing C++ in Visual Studio on Windows talking to the local Linux Subsystem

BTW, for those of you, like me, who love your Raspberry Pi tiny Linux computers...this is a great way to write C++ for those little devices as well. There's even a Blink example in File | New Project to start.

Also, for those of you who are very advanced, stop using Mingw-w64 and do cool stuff like compiling gcc 6.3 from source under WSL and having VS use that! I didn't realize that Visual Studio's C++ support lets you choose between a number of C++ compilers including both GCC and Clang.


Sponsor: Thanks to Redgate! Track every change to your database! See who made changes, what they did, & why, with SQL Source Control. Get a full version history in your source control system. See how.

About Scott

Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.

facebook twitter subscribe
About   Newsletter
Sponsored By
Hosting By
Dedicated Windows Server Hosting by SherWeb

Trying ASP.NET Core on the Google Cloud Platform "App Engine Flexible Environment"

March 30, '17 Comments [7] Posted in DotNetCore
Sponsored By

Last week I used Zeit and "now" to deploy an ASP.NET Core app (via a container) to the Zeit cloud. Tonight the kids are asleep so I thought I'd deploy to the Google Cloud. They've got beta support for open source ASP.NET so it's a perfect time. Google even has Google Cloud Tools for Visual Studio (2015).

I'll install the Google Cloud SDK. I checked "beta" as well.

Installing the Google Cloud SDK

Install it, login to your Google account and setup/select a project. I make a new folder and put an "app.yaml" in there with this inside as a directive to the Google Cloud Platform.

runtime: aspnetcore
env: flex

Here's a gratuitous screenshot:

App.yaml

I did a dotnet new, dotnet restore, and finally a:

dotnet publish -c Release

which makes a publish folder that will get sent up to the cloud.

IMPORTANT NOTE: I initially tried to push a .NET Core app using the .NET Core 1.1 runtime but Google Cloud's beta support in the flexible environment is set up for the 1.0.3 runtime (using their own custom docker base image) as of the time of this blog post, so you'll want to "dotnet new mvc --framework netcoreapp1.0" and set the "RuntimeFrameworkVersion" to get that specific shared LTS (Long Term Support) version. As soon as the Google Cloud flex runtime has the latest LTS (1.0.4, at the time of this writing) then apps would just roll forward.

<PropertyGroup>
  <TargetFramework>netcoreapp1.0</TargetFramework>
<RuntimeFrameworkVersion>1.0.3</RuntimeFrameworkVersion> </PropertyGroup>

Otherwise you'll get errors. Fortunately those errors are very clear.

.NET Core Runtime 1.0.3 supported

The walkthrough on Google Cloud suggests you copy the app.yaml file using a standard CLI copy command. However, since you're going to need that app.yaml EVERY publish, just add it to the csproj like this:

<ItemGroup>
<Content Include="app.yaml" CopyToOutputDirectory="Always" />
</ItemGroup>

This way it'll end up in publish automatically. You can then publish to the "AppEngine flexible environment:

dotnet restore
dotnet publish -c Release
gcloud beta app deploy .\bin\Release\netcoreapp1.0\publish\app.yaml
gcloud app browse // THIS IS JUST TO VISIT IT AFTER IT'S PUBLISHED

NOTE: You may get an ERROR that billing isn't enabled, or that the cloudbuild.googleapis.com aren't enabled. You'll need to ensure you have an active Free Trial, then go to the API Manager in the Google Cloud Platform dashboard and enable "Google Cloud Container Builder API." I also had to manually enable the API for the "Flexible" Environment and confirm I had a valid billing account.

Needed to enable some Billing APIs in the Google Cloud

Once I enabled a few APIs, I just did a standard "gcloud beta app deploy" as above:

gcloud beta app deploy

Pretty cool stuff! Here is my ASP.NET Core app running on GCP's Flex engine:

ASP.NET on Google Cloud

You can "tail" your app with "gcloud app logs tail -s default" and you'll see the output from .NET Core and ASP.NET (and Kestrel) in the Google Cloud!

gcloud app logs tail -s default

Or online in the Google "Stackdriver" logging page:

Google Stackdriver Logging page showing ASP.NET Core Logging

Go read up more on the Google Cloud Platform Blog. They even support Kubernetes clusters with ASP.NE Core apps packaged as Docker containers.


Sponsor: Thanks to Redgate! Track every change to your database! See who made changes, what they did, & why, with SQL Source Control. Get a full version history in your source control system. See how.

About Scott

Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.

facebook twitter subscribe
About   Newsletter
Sponsored By
Hosting By
Dedicated Windows Server Hosting by SherWeb

Command Line: Using dotnet watch test for continuous testing with .NET Core 1.0 and XUnit.net

March 27, '17 Comments [14] Posted in DotNetCore | Open Source
Sponsored By

I've installed .NET Core 1.0 on my machine. Let's see if I can get a class library and tests running and compiling automatically using only the command line. (Yes, some of you are freaked out by my (and other folks') appreciation of a nice, terse command line. Don't worry. You can do all this with a mouse if you want. I'm just enjoying the CLI.

NOTE: This is considerably updated from the project.json version in 2016.

First, I installed from http://dot.net/core. This should all work on Windows, Mac, or Linux.

C:\> md testexample & cd testexample

C:\testexample> dotnet new sln
Content generation time: 33.0582 ms
The template "Solution File" created successfully.

C:\testexample> dotnet new classlib -n mylibrary -o mylibrary
Content generation time: 40.5442 ms
The template "Class library" created successfully.

C:\testexample> dotnet new xunit -n mytests -o mytests
Content generation time: 87.5115 ms
The template "xUnit Test Project" created successfully.

C:\testexample> dotnet sln add mylibrary\mylibrary.csproj
Project `mylibrary\mylibrary.csproj` added to the solution.

C:\testexample> dotnet sln add mytests\mytests.csproj
Project `mytests\mytests.csproj` added to the solution.

C:\testexample> cd mytests

C:\testexample\mytests> dotnet add reference ..\mylibrary\mylibrary.csproj
Reference `..\mylibrary\mylibrary.csproj` added to the project.

C:\testexample\mytests> cd ..

C:\testexample> dotnet restore
Restoring packages for C:\Users\scott\Desktop\testexample\mytests\mytests.csproj...
Restoring packages for C:\Users\scott\Desktop\testexample\mylibrary\mylibrary.csproj...
Restore completed in 586.73 ms for C:\Users\scott\Desktop\testexample\mylibrary\mylibrary.csproj.
Installing System.Diagnostics.TextWriterTraceListener 4.0.0.
...SNIP...
Installing Microsoft.NET.Test.Sdk 15.0.0.
Installing xunit.runner.visualstudio 2.2.0.
Installing xunit 2.2.0.
Generating MSBuild file C:\Users\scott\Desktop\testexample\mytests\obj\mytests.csproj.nuget.g.props.
Generating MSBuild file C:\Users\scott\Desktop\testexample\mytests\obj\mytests.csproj.nuget.g.targets.
Writing lock file to disk. Path: C:\Users\scott\Desktop\testexample\mytests\obj\project.assets.json
Installed:
16 package(s) to C:\Users\scott\Desktop\testexample\mytests\mytests.csproj

C:\testexample> cd mytests & dotnet test

Build started, please wait...
Build completed.

Test run for C:\testexample\mytests\bin\Debug\netcoreapp1.1\mytests.dll(.NETCoreApp,Version=v1.1)
Microsoft (R) Test Execution Command Line Tool Version 15.0.0.0
Copyright (c) Microsoft Corporation. All rights reserved.

Starting test execution, please wait...
[xUnit.net 00:00:00.5539676] Discovering: mytests
[xUnit.net 00:00:00.6867799] Discovered: mytests
[xUnit.net 00:00:00.7341661] Starting: mytests
[xUnit.net 00:00:00.8691063] Finished: mytests

Total tests: 1. Passed: 1. Failed: 0. Skipped: 0.
Test Run Successful.
Test execution time: 1.8329 Seconds

Of course, I'm testing nothing yet but pretend there's a test in the tests.cs and something it's testing (that's why I added a reference) in the library.cs, OK?

Now I want to have my project build and tests run automatically as I make changes to the code. I can't "dotnet add tool" yet so I'll add this line to my test's project file:

<ItemGroup>
<DotNetCliToolReference Include="Microsoft.DotNet.Watcher.Tools" Version="1.0.0" />
</ItemGroup>

Like this:

Adding <DotNetCliToolReference Include="Microsoft.DotNet.Watcher.Tools" Version="1.0.0" />

Then I just dotnet restore to bring in the tool.

In order to start the tests, I don't write dotnet test, I run "dotnet watch test." The main command is watch, and then WATCH calls TEST. You can also dotnet watch run, etc.

NOTE: There's a color bug using only cmd.exe so on "DOS" you'll see some ANSI chars. That should be fixed in a minor release soon - the PR is in and waiting. On bash or PowerShell things look fin.

In this screenshot, you can see as I make changes to my test and hit save, the DotNetWatcher Tool sees the change and restarts my app, recompiles, and re-runs the tests.

Test Run Successful

All this was done from the command line. I made a solution file, made a library project and a test project, made the test project reference the library, then built and ran the tests. If I could add the tool from the command line I wouldn't have had to manually touch the project file at all.

Again, to be sure, all this is stuff you can (and do) do in Visual Studio manually all the time. But I'll race you anytime. ;)


Sponsor: Check out JetBrains Rider: a new cross-platform .NET IDE. Edit, refactor, test, build and debug ASP.NET, .NET Framework, .NET Core, or Unity applications. Learn more and get access to early builds!

About Scott

Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.

facebook twitter subscribe
About   Newsletter
Sponsored By
Hosting By
Dedicated Windows Server Hosting by SherWeb

Visual Studio 2017 can automatically recommend NuGet packages for unknown types

March 24, '17 Comments [9] Posted in VS2017
Sponsored By

There's a great feature in Visual Studio 2015.3 and Visual Studio 2017 that is turned off by default. It does use about ~10 megs of memory but it makes me so happy that I turn it on.

It's under C# | Advanced in Tools Options. Or you can just type "Advanced" in the Quick Launch Bar (via Ctrl+Q if you like) to jump there.

I turn on "Suggest usings for types in NuGet packages" and "Suggest usings for types in reference assemblies."

I turn on "Suggest usings for types in NuGet packages" and "Suggest usings for types in reference assemblies."

For example, if I am typing some code and start referencing a Type that isn't in my project but could be...you know how sometimes you just need a using statement to bring in a namespace? In this Web App, I already have Json.NET so it recommends a using statement to bring it into scope.

Can't find JSON

But in this Console App, I have no packages beyond the defaults. When I start using a type like JObject from a popular NuGet, Visual Studio can offer to install Json.NET for me!

Find and install latest version

Or another example:

XmlDocument

And then I can immediately continue typing with intellisense. If I know what I'm doing, I can bring in something like this without ever using the mouse or leaving the line.

JObject is now usable

Good stuff! 


Sponsor: Check out JetBrains Rider: a new cross-platform .NET IDE. Edit, refactor, test, build and debug ASP.NET, .NET Framework, .NET Core, or Unity applications. Learn more and get access to early builds!

About Scott

Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.

facebook twitter subscribe
About   Newsletter
Sponsored By
Hosting By
Dedicated Windows Server Hosting by SherWeb

Options for CSS and JS Bundling and Minification with ASP.NET Core

March 18, '17 Comments [16] Posted in ASP.NET | DotNetCore
Sponsored By

Maria and I were updating the NerdDinner sample app (not done yet, but soon) and were looking at various ways to do bundling and minification of the JSS and CS. There's runtime bundling on ASP.NET 4.x but in recent years web developers have used tools like Grunt or Gulp to orchestrate a client-side build process to squish their assets. The key is to find a balance that gives you easy access to development versions of JS/CSS assets when at dev time, while making it "zero work" to put minified stuff into production. Additionally, some devs don't need the Grunt/Gulp/npm overhead while others absolutely do. So how do you find balance? Here's how it works.

I'm in Visual Studio 2017 and I go File | New Project | ASP.NET Core Web App. Bundling isn't on by default but the configuration you need IS included by default. It's just minutes to enable and it's quite nice.

In my Solution Explorer is a "bundleconfig.json" like this:

// Configure bundling and minification for the project.
// More info at https://go.microsoft.com/fwlink/?LinkId=808241
[
{
"outputFileName": "wwwroot/css/site.min.css",
// An array of relative input file paths. Globbing patterns supported
"inputFiles": [
"wwwroot/css/site.css"
]
},
{
"outputFileName": "wwwroot/js/site.min.js",
"inputFiles": [
"wwwroot/js/site.js"
],
// Optionally specify minification options
"minify": {
"enabled": true,
"renameLocals": true
},
// Optionally generate .map file
"sourceMap": false
}
]

Pretty simple. Ins and outs. At the top of the VS editor you'll see this yellow prompt. VS knows you're in a bundleconfig.json and in order to use it effectively in VS you grab a small extension. To be clear, it's NOT required. It just makes it easier. The source is at https://github.com/madskristensen/BundlerMinifier. Slip this UI section if you just want Build-time bundling.

BundleConfig.json

If getting a prompt like this bugs you, you can turn all prompting off here:

Tools Options HTML Advanced Identify Helpful Extensions

Look at your Solution Explorer. See under site.css and site.js? There are associated minified versions of those files. They aren't really "under" them. They are next to them on the disk, but this hierarchy is a nice way to see that they are associated, and that one generates the other.

Right click on your project and you'll see this Bundler & Minifier menu:

Bundler and Minifier Menu

You can manually update your Bundles with this item as well as see settings and have bundling show up in the Task Runner Explorer.

Build Time Minification

The VSIX (VS extension) gives you the small menu and some UI hooks, but if you want to have your bundles updated at build time (useful if you don't use VS!) then you'll want to add a NuGet package called BuildBundlerMinifier.

You can add this NuGet package SEVERAL ways. Which is awesome.

  • Add it from the Manage NuGet Packages menu
  • Add it from the command line via "dotnet add package BuildBundlerMinifier"
    • Note that this adds it to your csproj without you having to edit it! It's like "nuget install" but adds references to projects!  The dotnet CLI is lovely.
  • If you have the VSIX installed, just right-click the bundleconfig.json and click "Enable bundle on build..." and you'll get the NuGet package.
    Enable bundle on build

Now bundling will run on build...

c:\WebApplication8\WebApplication8>dotnet build
Microsoft (R) Build Engine version 15
Copyright (C) Microsoft Corporation. All rights reserved.

Bundler: Begin processing bundleconfig.json
Bundler: Done processing bundleconfig.json
WebApplication8 -> c:\WebApplication8\bin\Debug\netcoreapp1.1\WebApplication8.dll

Build succeeded.
0 Warning(s)
0 Error(s)

...even from the command line with "dotnet build." It's all integrated.

This is nice for VS Code or users of other editors. Here's how it would work entirely from the command prompt:

$ dotnet new mvc
$ dotnet add package BuildBundlerMinifier
$ dotnet restore
$ dotnet run

Advanced: Using Gulp to handle Bundling/Minifying

If you outgrow this bundler or just like Gulp, you can right click and Convert to Gulp!

Convert to Gulp

Now you'll get a gulpfile.js that uses the bundleconfig.json and you've got full control:

gulpfile.js

And during the conversion you'll get the npm packages you need to do the work automatically:

npm and bower

I've found this to be a good balance that can get quickly productive with a project that gets bundling without npm/node, but I can easily grow to a larger, more npm/bower/gulp-driven front-end developer-friendly app.


Sponsor: Did you know VSTS can integrate closely with Octopus Deploy? Join Damian Brady and Brian A. Randell as they show you how to automate deployments from VSTS to Octopus Deploy, and demo the new VSTS Octopus Deploy dashboard widget. Register now!

About Scott

Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.

facebook twitter subscribe
About   Newsletter
Sponsored By
Hosting By
Dedicated Windows Server Hosting by SherWeb

Disclaimer: The opinions expressed herein are my own personal opinions and do not represent my employer's view in any way.