3 min read programming

Getting Started with Github Actions for .NET Core

When I pushed my recent Ghoplin mini-project to GitHub, it automatically offered to define a build action. I really liked the user experience here: GitHub offered the Action feature, detected my project type and generated a file, with project-appropriate defaults and in the correct folder.

I updated the dontnet version in the script and tried it; everything works and the task reports a success.

name: .NET Core

on: [push]

jobs:
  build:

    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v1
    - name: Setup .NET Core
      uses: actions/setup-dotnet@v1
      with:
        dotnet-version: 3.1.10
    - name: Build
      run: dotnet publish -r win-x64 --configuration ReleaseComplete

I wanted to take it a step further. GitHub has a marketplace with many different, though often sparsely documented, actions. They're really easy to plug into the workflow, though - just add new -name item into the step list in the YAML file.

In the end, I wanted an action that would

  • run on each push
  • build a (minified) executable for both Windows and Linux
  • let me download the resulting binaries, something the previous version wouldn't let me do
  • and even create a release, when a tag is present.

I ended up using these:

Trigger: Push. This is the default.

on: [push]

.NET setup

- name: Setup .NET Core
  uses: actions/setup-dotnet@v1
  with:
    dotnet-version: 3.1.100

When .NET is set up, I just run the build command twice - one step for each platform.

- name: Build for Linux
  run: dotnet publish -r linux-x64 --configuration ReleaseComplete
- name: Build for Windows
  run: dotnet publish -r win-x64 --configuration ReleaseComplete

Next, I need to upload the build artifacts, so that they're available for download from the Actions page.
I found on the marketplace that the action I want to use is actions/upload-artifact@v1.0.0, so I specify it in the uses entry.

I need to set the name, which specifies how the file will be called in the Artifacts download menu, and the path - which object will be uploaded under that name.

My case is really simple, since the entire project just builds into a single binary. 

- name: Upload artifact - Windows
  uses: actions/upload-artifact@v1.0.0
  with:
    name: Ghoplin.exe
    path: Ghoplin/bin/ReleaseComplete/netcoreapp3.1/win-x64/publish/Ghoplin.exe

I do that analogously for Linux.

The last step is the release. GitHub won't let me create a release without an associated tag. Therefore I need the conditional if: startsWith(github.ref, 'refs/tags/'). That makes sure this step only runs when a tag is pushed. So whenever I push a tag, this step makes a release, adds the required files and names it with the name of the tag.

Two notes: don't forget the pipe on the line saying files: |. It tells YAML that what follows is a list of items.
And while the GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} line seems to be necessary, I did not have to do any extra steps to make it work and pass the appropriate secret.

- name: Make Release
  uses: softprops/action-gh-release@v1
  if: startsWith(github.ref, 'refs/tags/')
  with:
    files: |
      Ghoplin/bin/ReleaseComplete/netcoreapp3.1/linux-x64/publish/Ghoplin
      Ghoplin/bin/ReleaseComplete/netcoreapp3.1/win-x64/publish/Ghoplin.exe
  env:
    GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

This is the script in its entirety

name: .NET Core

on: [push]

jobs:
  build:

    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v1
    - name: Setup .NET Core
      uses: actions/setup-dotnet@v1
      with:
        dotnet-version: 3.1.100
    - name: Build for Linux
      run: dotnet publish -r linux-x64 --configuration ReleaseComplete
    - name: Build for Windows
      run: dotnet publish -r win-x64 --configuration ReleaseComplete
    - name: Upload artifact - Linux
      uses: actions/upload-artifact@v1.0.0
      with:
        name: Ghoplin
        path: Ghoplin/bin/ReleaseComplete/netcoreapp3.1/linux-x64/publish/Ghoplin
    - name: Upload artifact - Windows
      uses: actions/upload-artifact@v1.0.0
      with:
        name: Ghoplin.exe
        path: Ghoplin/bin/ReleaseComplete/netcoreapp3.1/win-x64/publish/Ghoplin.exe
    - name: Make Release
      uses: softprops/action-gh-release@v1
      if: startsWith(github.ref, 'refs/tags/')
      with:
        files: |
          Ghoplin/bin/ReleaseComplete/netcoreapp3.1/linux-x64/publish/Ghoplin
          Ghoplin/bin/ReleaseComplete/netcoreapp3.1/win-x64/publish/Ghoplin.exe
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

I'm hoping add actions to other projects one of these days.

zblesk

zblesk