Scott Hanselman

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

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


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.

<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:

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

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

NOTE: You may get an ERROR that billing isn't enabled, or that the 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.

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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.

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

March 27, '17 Comments [14] Posted in DotNetCore | Open Source
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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 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.
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
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
Copyright (c) Microsoft Corporation. All rights reserved.

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

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

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. ;)

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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.

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

March 18, '17 Comments [16] Posted in ASP.NET | DotNetCore
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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
"outputFileName": "wwwroot/css/site.min.css",
// An array of relative input file paths. Globbing patterns supported
"inputFiles": [
"outputFileName": "wwwroot/js/site.min.js",
"inputFiles": [
// 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 Slip this UI section if you just want Build-time bundling.


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:


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.

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ZEIT now deployments of open source ASP.NET Core web apps with Docker

March 15, '17 Comments [14] Posted in ASP.NET | Docker | DotNetCore
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ZEIT is a new cloud service and "now" is the name of their deployment tool. ZEIT World is their DNS service. If you head over to you'll see a somewhat cryptic animated gif that shows how almost impossibly simple it is to deploy a web app with ZEIT now.

ZEIT works with .NET Core and ASP.NET

You can make a folder, put an index.html (for example) in it and just run "now." You'll automatically get a website with an autogenerated name and it'll be live. It's probably the fastest and easiest deploy I've ever seen. Remember when Heroku (then Azure, then literally everyone) started using git for deployment? Clearly being able to type "now" and just get a web site on the public internet was the next step. (Next someone will make "up" which will then get replaced with just pressing ENTER on an empty line! ;) )

Jokes aside, now is clean and easy. I appreciate their organizational willpower to make an elegant and simple command line tool. I suspect it's harder than it looks to keep things simple.

All of their examples use JavaScript and node.js, but they also support Docker, which means they support open source ASP.NET Core on .NET Core! But do they know they do? ;) Let's find out.

And more importantly, how easy is it? Can I take a site from concept to production in minutes? Darn tootin' I can.

First, make a quick ASP.NET Core app. I'll use the MVC template with Bootstrap.

C:\Users\scott\zeitdotnet>dotnet new mvc
Content generation time: 419.5337 ms
The template "ASP.NET Core Web App" created successfully.

I'll do a quick dotnet restore to get the packages for my project.

C:\Users\scott\zeitdotnet>dotnet restore
Restoring packages for C:\Users\scott\zeitdotnet\zeitdotnet.csproj...
Generating MSBuild file C:\Users\scott\zeitdotnet\obj\zeitdotnet.csproj.nuget.g.props.
Generating MSBuild file C:\Users\scott\zeitdotnet\obj\zeitdotnet.csproj.nuget.g.targets.
Writing lock file to disk. Path: C:\Users\scott\zeitdotnet\obj\project.assets.json
Restore completed in 2.93 sec for C:\Users\scott\zeitdotnet\zeitdotnet.csproj.

NuGet Config files used:
C:\Program Files (x86)\NuGet\Config\Microsoft.VisualStudio.Offline.config

Feeds used:
C:\Program Files (x86)\Microsoft SDKs\NuGetPackages\

Now I need to add a Dockerfile. I'll make one in the root that looks like this:

FROM microsoft/aspnetcore
LABEL name="zeitdotnet"
ENTRYPOINT ["dotnet", "zeitdotnet.dll"]
ARG source=.
COPY $source .

Note that I could have ZEIT build my app for me if I used the aspnetcore Dockerfile that includes the .NET Core SDK, but that would not only make my deployment longer, it would also make my docker images a LOT larger. I want to include JUST the .NET Core runtime in my image, so I'll build and publish locally.

ZEIT now is going to need to see my Dockerfile, and since I want my app to include the binaries (I don't want to ship my source in the Docker image up to ZEIT) I need to mark my Dockerfile as "Content" and make sure it's copied to the publish folder when my app is built and published.

  <None Remove="Dockerfile" />

  <Content Include="Dockerfile">

I'll add this my project's csproj file. If I was using Visual Studio, this is the same as right clicking on the Properties of the Dockerfile, setting it to Content and then "Always Copy to Output Directory."

Now I'll just build and publish to a folder with one command:

C:\Users\scott\zeitdotnet>dotnet publish
Microsoft (R) Build Engine version 15.1.548.43366
Copyright (C) Microsoft Corporation. All rights reserved.

zeitdotnet -> C:\Users\scott\zeitdotnet\bin\Debug\netcoreapp1.1\zeitdotnet.dll

And finally, from the .\bin\Debug\netcoreapp1.1\ folder I run "now." (Note that I've installed now and signed up for their service, of course.)

> Deploying ~\zeitdotnet\bin\Debug\netcoreapp1.1\publish
> Ready! (copied to clipboard) [3s]
> Upload [====================] 100% 0.0s
> Sync complete (196.18kB) [2s]
> Initializing…
> Building
> ▲ docker build
> ---> 035a0a1401c3
> Removing intermediate container 289b9e4ce5d9
> Step 6 : EXPOSE 80
> ---> Running in efb817308333
> ---> fbac2aaa3039
> Removing intermediate container efb817308333
> Step 7 : COPY $source .
> ---> ff009cfc48ea
> Removing intermediate container 8d650c1867cd
> Successfully built ff009cfc48ea
> ▲ Storing image
> ▲ Deploying image
> Deployment complete!

Now has put the generated URL in my clipboard (during deployment you'll get redirected to a lovely status page) and when it's deployed I can visit my live site. But, that URL is not what I want. I want to use a custom URL.

I can take one of my domains and set it up with ZEIT World's DNS but I like DNSimple (ref).

I can add my domain as an external one after adding a TXT record to my DNS to verify I own it. Then I setup a CNAME to point my subdomain to

C:\Users\scott\Desktop\zeitdotnet>now alias
> is a custom domain.
> Verifying the DNS settings for (see for help)
> Verification OK!
> Provisioning certificate for
> Success! Alias created: now points to [copied to clipboard]

And that's it. It even has a nice SSL certificate that they applied for me. It doesn't terminate to SSL all the way into the docker container's Kestral web server, but for most things that aren't banking it'll be just fine.

All in all, a lovely experience. Here's my Hello World ASP.NE Core app running in ZEIT and deployed with now  at (if you are visiting this long after this was published, this sample MAY be gone.)

I am still learning about this (this whole exercise was about 30 total minutes and asking Glenn Condron a docker question) so I'm not clear how this would work in a large multi-container deployment, but as long as your site is immutable (don't write to the container's local disk!) ZEIT says it will scale your single containers. Perhaps docker-compose support is coming?

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.

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Xamarin .NET Workbooks - Interactive Computing is a stellar learning tool

February 24, '17 Comments [11] Posted in DotNetCore | Learning .NET
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I've been thinking a lot about how to best teach .NET and C#/F# to folks who are new to the space. We've added an in-browser no-install C# tutorial at You can run through almost a few days lessons in C# without installing anything. Heck, it's useful even if you just want to brush up on your skills.

When I spoke with Safia Abdalla a few months ago she re-introduced me to the ideas behind Interactive Computing and the whole ecosystem around Jupyter Notebooks, and the Nteract project Safia works on. It's pretty amazing.

Pythonistas are familiar with Jupyter and the idea of a notebook that cleanly mixes prose and code. This ecosystem is very friendly to data scientists that are (perhaps) more scientist and less developer. People for whom an IDE is not as interesting as "electric paper."

In fact, many people don't realize that the Microsoft Azure Cloud supports hosting of Jupyter Notebooks using Python, R, and F#.

Azure Notebooks

Notebooks are a great learning resource that go beyond a REPL (an simple interactive console) in that they are effectively textbooks with islands of interactive code. It's even more powerful when you consider graphics, charts, and other interactive models.

Xamarin has a thing called Xamarin Workbooks (I'm calling them .NET Workbooks in my head) that you should download and check out RIGHT NOW. Go get Xamarin Workbooks & Inspector for Windows (or download for Mac). Start playing around with workbooks or try out the samples.

I'm going to try teaching my C# and .NET courses for at least the first day or two using Xamarin .NET Workbooks. I think they have huge potential and I'm thrilled that Miguel and friends are investing so much in them. The potential for these as a learning tool that sits between a REPL and an IDE is huge.

The page at is FILLED with amazing example workbooks and lessons, and it's growing. It has section not only on C# but Android, Games, Graphics as a concept, iOS, WPF, and so much more.

I run it and start here:

Xamarin Workbooks

Then I start typing...prose first! Just real sentences. Then I add some code. Notice that I'm not doing Console.WriteLine, I'm just assigning a variable. Xamarin Workbooks makes a nice visualization of my variable.

var scott = "Hanselman"

The prose is ignored (by the compiler) but the code cells and built upon each other and when you execute one you're executing up to that point. Great for building up concepts.

You can print in other libraries and built upon them like in this chart example using the Urho library.

Charts in Xamarin Workbooks

Not to put to fine a point on it, but you can write really fully featured examples or games in Xamarin Workbooks. Here's a fully 3D realized planet earth WITH SATELLITES. Again, with not just sample code but explanatory prose. It's a textbook come to life.

THIS is how I wish I learned programming 25 years ago. I'd loved to have turned (or demo'ed) a .workbook file. I'm thrilled to see C# folks be able to do simple things that Jupyter users have enjoyed for so long.

3D Earth in Xamarin Workbooks

What do you think? Would this be a good way to deliver a course on learning .NET and C#?

Sponsor: Big thanks to Progress! They recently published a comprehensive whitepaper on The State of C#, discussing the history of C#, what’s new in C# 7 and whether C# is still a viable language. Check it out!

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.

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