Lightning Talk - .NET CLI in 5 Minutes

Wrote this up after reading through Jeremy Miller's article on .NET CLI as a 5 minute lightning talk.

.NET Core Command Line Interface

Can we be friends with it?

Test Setup

  • .NET Core installed 2.2
  • Windows Subsystem for Linux (Ubuntu 18.04 LTS image)

Check your version of .NET Core

dotnet --info

.NET Core SDK (reflecting any global.json):
 Version:   2.2.105
 Commit:    7cecb35b92

Runtime Environment:
 OS Name:     ubuntu
 OS Version:  18.04
 OS Platform: Linux
 RID:         ubuntu.18.04-x64
 Base Path:   /usr/share/dotnet/sdk/2.2.105/

Create a working directory

mkdir best && cd best

Run the command line new option

dotnet new

Usage: new [options]

  -h, --help          Displays help for this command.
  -l, --list          Lists templates containing the specified name. If no name is specified, lists all templates.
  -n, --name          The name for the output being created. If no name is specified, the name of the current directory is used.
  -o, --output        Location to place the generated output.
  -i, --install       Installs a source or a template pack.
  -u, --uninstall     Uninstalls a source or a template pack.
  --nuget-source      Specifies a NuGet source to use during install.
  --type              Filters templates based on available types. Predefined values are "project", "item" or "other".
  --dry-run           Displays a summary of what would happen if the given command line were run if it would result in a template creation.
  --force             Forces content to be generated even if it would change existing files.
  -lang, --language   Filters templates based on language and specifies the language of the template to create.

Templates                                         Short Name         Language          Tags                                 
Console Application                               console            [C#], F#, VB      Common/Console                   
Class library                                     classlib           [C#], F#, VB      Common/Library                   
xUnit Test Project                                xunit              [C#], F#, VB      Test/xUnit                       
Razor Class Library                               razorclasslib      [C#]              Web/Razor/Library/Razor Class Library
ASP.NET Core Web API                              webapi             [C#], F#          Web/WebAPI    

Create a Web API project

dotnet new webapi --name tippytop

The template "ASP.NET Core Web API" was created successfully.

Processing post-creation actions...
Running 'dotnet restore' on tippytop/tippytop.csproj...
  Restoring packages for /mnt/c/Users/rnmichael/Documents/best/tippytop/tippytop.csproj...
  Generating MSBuild file /mnt/c/Users/rnmichael/Documents/best/tippytop/obj/tippytop.csproj.nuget.g.props.
  Generating MSBuild file /mnt/c/Users/rnmichael/Documents/best/tippytop/obj/tippytop.csproj.nuget.g.targets.
  Restore completed in 4.45 sec for /mnt/c/Users/rnmichael/Documents/best/tippytop/tippytop.csproj.

Restore succeeded.

Create an empty solution file

dotnet new sln

The template "Solution File" was created successfully.

Add the current project to the Solution

dotnet sln best.sln add tippytop/tippytop.csproj

Project `tippytop/tippytop.csproj` added to the solution.

Create a test project (using xUnit)

dotnet new xunit --output tippytop.tests

The template "xUnit Test Project" was created successfully.

Processing post-creation actions...
Running 'dotnet restore' on tippytop.tests/tippytop.tests.csproj...
  Restoring packages for /mnt/c/Users/rnmichael/Documents/best/tippytop.tests/tippytop.tests.csproj...
  Generating MSBuild file /mnt/c/Users/rnmichael/Documents/best/tippytop.tests/obj/tippytop.tests.csproj.nuget.g.props.
  Generating MSBuild file /mnt/c/Users/rnmichael/Documents/best/tippytop.tests/obj/tippytop.tests.csproj.nuget.g.targets.
  Restore completed in 2.65 sec for /mnt/c/Users/rnmichael/Documents/best/tippytop.tests/tippytop.tests.csproj.

Restore succeeded.

Add the test project to your Solution

dotnet sln best.sln add tippytop.tests/tippytop.tests.csproj

Project `tippytop.tests/tippytop.tests.csproj` added to the solution.

Reference your Web API project in the test project

dotnet add tippytop.tests/tippytop.tests.csproj reference tippytop/tippytop.csproj

Reference `..\tippytop\tippytop.csproj` added to the project.

Build the solution

dotnet build best.sln

Microsoft (R) Build Engine version 15.9.20+g88f5fadfbe for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.

  Restoring packages for /mnt/c/Users/rnmichael/Documents/best/tippytop.tests/tippytop.tests.csproj...
  Restore completed in 410.61 ms for /mnt/c/Users/rnmichael/Documents/best/tippytop/tippytop.csproj.
  Restore completed in 509.78 ms for /mnt/c/Users/rnmichael/Documents/best/tippytop.tests/tippytop.tests.csproj.
  tippytop -> /mnt/c/Users/rnmichael/Documents/best/tippytop/bin/Debug/netcoreapp2.2/tippytop.dll
  tippytop.tests -> /mnt/c/Users/rnmichael/Documents/best/tippytop.tests/bin/Debug/netcoreapp2.2/tippytop.tests.dll

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

Time Elapsed 00:00:05.52

Run tests

dotnet build && dotnet clean && dotnet test

Run the solution

dotnet run --project tippytop/tippytop.csproj

Test the default response

curl -X GET https://localhost:5001/api/values -H 'cache-control: no-cache' --insecure | jq '.'


Create a Dockerfile

Place this file in the tippytop folder

FROM microsoft/dotnet:2.2-sdk AS build-env
COPY *.csproj ./
RUN dotnet restore
COPY . ./
RUN dotnet publish -c Release -o out
FROM microsoft/dotnet:aspnetcore-runtime
COPY --from=build-env /app/out .
ENTRYPOINT ["dotnet", "tippytop.dll"]

Build the Docker image

Move to webapi folder

cd tippytop

Build and tag docker image

docker build -t tippytop .

Run the new Docker image

docker run -d -p 8080:80 --name myapp tippytop

Test the Web API in the running container

curl -X GET http://localhost:8080/api/values -H 'cache-control: no-cache' | jq '.'


  • Command Line Interface support for .NET Core works!!!
  • Scripting templates, setups, and tests are good options
  • Microsoft is pushing developers to automate and familiarize themselves with these tools going forward
  • Understanding the CLI will help you debug problems in Visual Studio

Your thoughts?

Thank you