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

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

- 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:

- 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:

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:

- 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:

- 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)

- 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:

- 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.microsoft.com/dotnet/runtime-deps:8.0-noble-chiseled

The runtime-deps base image is sufficient for AOT binaries since they include the runtime. See [skill:dotnet-native-aot] for AOT MSBuild properties and [skill:dotnet-containers] for base image selection.

---

Artifact Signing

NuGet Package Signing

Sign NuGet packages with a certificate for tamper detection:

- name: Sign NuGet packages
  run: |
    set -euo pipefail
    dotnet nuget sign ./nupkgs/*.nupkg \
      --certificate-path ${{ runner.temp }}/signing-cert.pfx \
      --certificate-password ${{ secrets.CERT_PASSWORD }} \
      --timestamper http://timestamp.digicert.com

For CI, extract the certificate from a base64-encoded secret:

- name: Decode signing certificate
  shell: bash
  run: |
    set -euo pipefail
    echo "${{ secrets.SIGNING_CERT_BASE64 }}" | base64 -d > "${{ runner.temp }}/signing-cert.pfx"

- name: Sign NuGet packages
  run: |
    set -euo pipefail
    dotnet nuget sign ./nupkgs/*.nupkg \
      --certificate-path ${{ runner.temp }}/signing-cert.pfx \
      --certificate-password ${{ secrets.CERT_PASSWORD }} \
      --timestamper http://timestamp.digicert.com

- name: Clean up certificate
  if: always()
  run: rm -f "${{ runner.temp }}/signing-cert.pfx"

Container Image Signing with Sigstore

Sign container images with keyless signing via sigstore/cosign:

- name: Install cosign
  uses: sigstore/cosign-installer@v3

- name: Sign container image
  env:
    COSIGN_EXPERIMENTAL: '1'
  run: |
    set -euo pipefail
    cosign sign --yes ghcr.io/${{ github.repository }}@${{ steps.build.outputs.digest }}

Keyless signing uses GitHub's OIDC token -- no private key management required.

---

SBOM Generation

Microsoft SBOM Tool

Generate a Software Bill of Materials for supply chain transparency:

- name: Generate SBOM
  uses: microsoft/sbom-action@v0
  with:
    BuildDropPath: ./nupkgs
    PackageName: MyLibrary
    PackageVersion: ${{ steps.version.outputs.version }}
    NamespaceUriBase: https://github.com/${{ github.repository }}

- name: Upload SBOM
  uses: actions/upload-artifact@v4
  with:
    name: sbom-${{ steps.version.outputs.version }}
    path: ./nupkgs/_manifest/
    retention-days: 365

SBOM for Container Images

- name: Generate container SBOM
  uses: anchore/sbom-action@v0
  with:
    image: ghcr.io/${{ github.repository }}:${{ steps.version.outputs.version }}
    artifact-name: container-sbom
    output-file: container-sbom.spdx.json

Attach SBOM to GitHub Release

- name: Create GitHub Release with SBOM
  uses: softprops/action-gh-release@v2
  with:
    files: |
      ./nupkgs/*.nupkg
      ./nupkgs/_manifest/spdx_2.2/manifest.spdx.json
    generate_release_notes: true

---

Conditional Publishing on Tags and Releases

Tag Pattern Matching

on:
  push:
    tags:
      - 'v[0-9]+.[0-9]+.[0-9]+'         # stable: v1.2.3
      - 'v[0-9]+.[0-9]+.[0-9]+-*'        # pre-release: v1.2.3-preview.1

jobs:
  publish:
    runs-on: ubuntu-latest
    steps:
      - name: Determine release type
        id: release-type
        shell: bash
        run: |
          set -euo pipefail
          VERSION="${GITHUB_REF_NAME#v}"
          if [[ "$VERSION" == *-* ]]; then
            echo "prerelease=true" >> "$GITHUB_OUTPUT"
          else
            echo "prerelease=false" >> "$GITHUB_OUTPUT"
          fi
          echo "version=$VERSION" >> "$GITHUB_OUTPUT"

Release-Triggered Publishing

Publish only when a GitHub Release is created (provides manual approval gate):

on:
  release:
    types: [published]

jobs:
  publish:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          ref: ${{ github.event.release.tag_name }}

      - name: Extract version
        id: version
        shell: bash
        run: |
          set -euo pipefail
          VERSION="${{ github.event.release.tag_name }}"
          VERSION="${VERSION#v}"
          echo "version=$VERSION" >> "$GITHUB_OUTPUT"

      - name: Pack and publish
        run: |
          set -euo pipefail
          dotnet pack -c Release -p:Version=${{ steps.version.outputs.version }} -o ./nupkgs
          dotnet nuget push ./nupkgs/*.nupkg \
            --api-key ${{ secrets.NUGET_API_KEY }} \
            --source https://api.nuget.org/v3/index.json \
            --skip-duplicate

---

Agent Gotchas

1. Always use --skip-duplicate with dotnet nuget push -- without it, re-running a publish workflow for an already-published version fails the job instead of being idempotent.
2. Never hardcode API keys in workflow files -- use ${{ secrets.NUGET_API_KEY }} or environment-scoped secrets for all credentials.
3. Use set -euo pipefail in all multi-line bash steps -- without pipefail, a failure in a piped command does not propagate, producing false-green CI.
4. Clean up signing certificates in an if: always() step -- temporary files with private key material must be removed even when the job fails.
5. SDK container publish requires Docker daemon -- dotnet publish with PublishProfile=DefaultContainer needs Docker installed on the runner; use ubuntu-latest which includes Docker.
6. AOT publish requires matching RID -- dotnet publish -r linux-x64 must match the runner OS; do not use -r win-x64 on ubuntu-latest.
7. Tag-triggered workflows do not run on pull requests -- tags pushed from PRs still trigger the workflow; use if: github.ref_type == 'tag' as an extra guard if needed.
8. GHCR authentication uses GITHUB_TOKEN, not a PAT -- for public repositories, packages: write permission is sufficient; PATs are only needed for cross-repository access.