dotnet-gha-publish

What this skill does

# dotnet-gha-publish

Publishing workflows for .NET projects in GitHub Actions: NuGet package push to nuget.org and GitHub Packages, container image build and push to GHCR/DockerHub/ACR, artifact signing with NuGet signing and sigstore, SBOM generation with Microsoft SBOM tool, and conditional publishing triggered by tags and releases.

**Version assumptions:** `actions/setup-dotnet@v4` for .NET 8/9/10. `docker/build-push-action@v6` for container image builds. `docker/login-action@v3` for registry authentication. .NET SDK container publish (`dotnet publish` with `PublishContainer`) for Dockerfile-free container builds.

**Scope boundary:** This skill owns artifact publishing workflows from GitHub Actions. Container image authoring (Dockerfile best practices, SDK container properties) is owned by [skill:dotnet-containers]. Native AOT compilation configuration is owned by [skill:dotnet-native-aot] -- this skill references AOT for CI pipeline configuration only. CLI-specific release pipelines (build-package-release for CLI binaries) are owned by [skill:dotnet-cli-release-pipeline]. Starter CI templates are owned by [skill:dotnet-add-ci].

**Out of scope:** Container image authoring (Dockerfile, base image selection) -- see [skill:dotnet-containers]. Native AOT MSBuild configuration -- see [skill:dotnet-native-aot]. CLI release pipelines -- see [skill:dotnet-cli-release-pipeline]. Starter CI templates -- see [skill:dotnet-add-ci]. Azure DevOps publishing -- see [skill:dotnet-ado-publish]. Deployment to target environments -- see [skill:dotnet-gha-deploy].

Cross-references: [skill:dotnet-containers] for container image authoring and SDK container properties, [skill:dotnet-native-aot] for AOT publish configuration in CI, [skill:dotnet-cli-release-pipeline] for CLI-specific release automation, [skill:dotnet-add-ci] for starter publish templates.

---

## NuGet Push to nuget.org

### Tag-Triggered Package Publishing

```yaml
name: Publish NuGet Package

on:
  push:
    tags:
      - 'v*'

permissions:
  contents: read

jobs:
  publish:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Setup .NET
        uses: actions/setup-dotnet@v4
        with:
          dotnet-version: '8.0.x'

      - name: Extract version from tag
        id: version
        shell: bash
        run: |
          set -euo pipefail
          VERSION="${GITHUB_REF_NAME#v}"
          echo "version=$VERSION" >> "$GITHUB_OUTPUT"

      - name: Pack
        run: |
          set -euo pipefail
          dotnet pack src/MyLibrary/MyLibrary.csproj \
            -c Release \
            -p:Version=${{ steps.version.outputs.version }} \
            -o ./nupkgs

      - name: Push to nuget.org
        run: |
          set -euo pipefail
          dotnet nuget push ./nupkgs/*.nupkg \
            --api-key ${{ secrets.NUGET_API_KEY }} \
            --source https://api.nuget.org/v3/index.json \
            --skip-duplicate
```

The `--skip-duplicate` flag prevents failures when a package version is already published (idempotent retries).

### Publishing to GitHub Packages

```yaml
- name: Push to GitHub Packages
  run: |
    set -euo pipefail
    dotnet nuget push ./nupkgs/*.nupkg \
      --api-key ${{ secrets.GITHUB_TOKEN }} \
      --source https://nuget.pkg.github.com/${{ github.repository_owner }}/index.json \
      --skip-duplicate
```

### Publishing to Both Feeds

Publish to nuget.org for public consumption and GitHub Packages for organization-internal pre-release:

```yaml
- name: Push to nuget.org (stable releases)
  if: "!contains(steps.version.outputs.version, '-')"
  run: |
    set -euo pipefail
    dotnet nuget push ./nupkgs/*.nupkg \
      --api-key ${{ secrets.NUGET_API_KEY }} \
      --source https://api.nuget.org/v3/index.json \
      --skip-duplicate

- name: Push to GitHub Packages (all versions)
  run: |
    set -euo pipefail
    dotnet nuget push ./nupkgs/*.nupkg \
      --api-key ${{ secrets.GITHUB_TOKEN }} \
      --source https://nuget.pkg.github.com/${{ github.repository_owner }}/index.json \
      --skip-duplicate
```

Pre-release versions (containing `-` like `1.2.3-preview.1`) go only to GitHub Packages; stable versions go to both.

---

## Container Image Build and Push

### Dockerfile-Based Build with docker/build-push-action

For projects with a custom Dockerfile -- see [skill:dotnet-containers] for Dockerfile authoring guidance:

```yaml
name: Publish Container Image

on:
  push:
    tags:
      - 'v*'

permissions:
  contents: read
  packages: write

jobs:
  container:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Log in to GHCR
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ghcr.io/${{ github.repository }}
          tags: |
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=sha

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
```

### SDK Container Publish (Dockerfile-Free)

Use .NET SDK container publish for projects without a Dockerfile -- see [skill:dotnet-containers] for `PublishContainer` MSBuild configuration:

```yaml
- name: Setup .NET
  uses: actions/setup-dotnet@v4
  with:
    dotnet-version: '8.0.x'

- name: Log in to GHCR
  run: |
    set -euo pipefail
    echo "${{ secrets.GITHUB_TOKEN }}" | \
      docker login ghcr.io -u ${{ github.actor }} --password-stdin

- name: Publish container image
  run: |
    set -euo pipefail
    VERSION="${GITHUB_REF_NAME#v}"
    dotnet publish src/MyApp/MyApp.csproj \
      -c Release \
      -p:PublishProfile=DefaultContainer \
      -p:ContainerRegistry=ghcr.io \
      -p:ContainerRepository=${{ github.repository }} \
      -p:ContainerImageTags="\"${VERSION};latest\""
```

### Push to Multiple Registries

Push to GHCR and DockerHub from the same workflow:

```yaml
- name: Log in to GHCR
  uses: docker/login-action@v3
  with:
    registry: ghcr.io
    username: ${{ github.actor }}
    password: ${{ secrets.GITHUB_TOKEN }}

- name: Log in to DockerHub
  uses: docker/login-action@v3
  with:
    username: ${{ secrets.DOCKERHUB_USERNAME }}
    password: ${{ secrets.DOCKERHUB_TOKEN }}

- name: Extract metadata
  id: meta
  uses: docker/metadata-action@v5
  with:
    images: |
      ghcr.io/${{ github.repository }}
      ${{ secrets.DOCKERHUB_USERNAME }}/${{ github.event.repository.name }}
    tags: |
      type=semver,pattern={{version}}

- name: Build and push to both registries
  uses: docker/build-push-action@v6
  with:
    context: .
    push: true
    tags: ${{ steps.meta.outputs.tags }}
    labels: ${{ steps.meta.outputs.labels }}
```

### Push to Azure Container Registry (ACR)

```yaml
- name: Log in to ACR
  uses: docker/login-action@v3
  with:
    registry: ${{ secrets.ACR_LOGIN_SERVER }}
    username: ${{ secrets.ACR_USERNAME }}
    password: ${{ secrets.ACR_PASSWORD }}

- name: Build and push to ACR
  uses: docker/build-push-action@v6
  with:
    context: .
    push: true
    tags: ${{ secrets.ACR_LOGIN_SERVER }}/myapp:${{ github.ref_name }}
```

### Native AOT Container Publish

Publish a Native AOT binary as a container image. AOT configuration is owned by [skill:dotnet-native-aot]; this shows the CI pipeline step only:

```yaml
- name: Publish AOT container
  run: |
    set -euo pipefail
    dotnet publish src/MyApp/MyApp.csproj \
      -c Release \
      -r linux-x64 \
      -p:PublishAot=true \
      -p:PublishProfile=DefaultContainer \
      -p:ContainerRegistry=ghcr.io \
      -p:ContainerRepository=${{ github.repository }} \
      -p:ContainerBaseImage=mcr.mic