When publishing how do I target specific .NET Core Runtimes?

Question

When I publish my .NET Core app, it outputs a runtimes directory with the following sub-directories:

- publish/runtimes/
   - debian.8-x64/
   - fedora.23-x64/
   - fedora.24-x64/
   - opensuse.13.2-x64/
   - opensuse.42.1-x64/
   - osx/
   - osx.10.10-x64/
   - rhel.7-x64/
   - ubuntu.14.04-x64/
   - ubuntu.16.04-x64/
   - ubuntu.16.10-x64/
   - unix/
   - win/

On my CI/CD server I publish my applications with this command:

dotnet publish -c Release -o ..\publish

My publish settings in the project file are the following:

• Target Framework: netcoreapp2.1
• Deployment Mode: Framework-Dependent
• Target Runtime: win-x64

I only plan to publish this application on Windows 2016 Server so the OSX/Linux/Unix runtimes folders are not necessary. Worse in several cases these runtimes folders contain known vulnerable dlls which lead to false positive OSA scans.

Is there a way to configure the project to only output the win runtime folder?

Update

I have tried the suggestions by @ahsteele and the output of adding the RIDs to my csproj files is the same as if I did not specify the RIDs.

When I run CI/CD command example

dotnet publish -c Release -r win10-x86 -o ..\publish

I believe it creates a self-contained deployment. As my publish directory goes from being 55MB to 120MB and from 237 files to 482 files.

Update 2

I have tried specifying my startup project for the publish step and it builds the run time directories to be more compact.

Here is the build command I am running:

dotnet publish .\startupProject.csproj -c Release -o ..\publish

And this is the output:

- publish/runtimes/
   - unix/
   - win/

Some of the projects in my solution do specify netstandard2.0 and some specify netcoreapp2.0. Does Microsoft document anywhere that if you don't specify a target framework or a specific csproj file, it will give you all of the target frameworks for all of the possible runtimes?

Answer 1

You should be able to specify your runtime with the dotnet publish -r switch. From the .NET Core RID Catalog - Windows RIDs the Windows 10 / Windows Server 2016 RIDs are:

• win10-x64
• win10-x86
• win10-arm
• win10-arm64

Meaning that your CI/CD command can specify the runtime:

dotnet publish -c Release -r win10-x86 -o ..\publish

Alternatively a single RID can be set in the <RuntimeIdentifier> element of your project file:

<RuntimeIdentifier>win10-x64</RuntimeIdentifier>

Multiple RIDs can be defined as a semicolon-delimited list in the project file's <RuntimeIdentifiers> element:

<RuntimeIdentifiers>win10-x64;win10-x86</RuntimeIdentifiers>