Docker

semrel is available as an official Docker image at ghcr.io/SemRels/semrel.

Image variants

Tag	Base	Notes
ghcr.io/SemRels/semrel:latest	distroless	Minimal, no shell. Requires git in host or mount.
ghcr.io/SemRels/semrel:1.4.0	distroless	Version-pinned distroless
ghcr.io/SemRels/semrel:latest-alpine	Alpine 3	Includes git, ca-certificates, shell
ghcr.io/SemRels/semrel:1.4.0-alpine	Alpine 3	Version-pinned Alpine

Tipp

Use the alpine variant in CI pipelines — it bundles git and ca-certificates, which are required for repository operations.

Quickstart

# Dry run in current directory
docker run --rm \
  -v "$(pwd):/workspace" \
  -w /workspace \
  -e GITHUB_TOKEN="$GITHUB_TOKEN" \
  ghcr.io/SemRels/semrel:latest-alpine release --dry-run

GitHub Actions

jobs:
  release:
    runs-on: ubuntu-latest
    container:
      image: ghcr.io/SemRels/semrel:latest-alpine
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Run semrel
        run: semrel release
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Or use it as a Docker action:

- name: Run semrel
  uses: docker://ghcr.io/SemRels/semrel:latest-alpine
  with:
    args: release
  env:
    GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

GitLab CI

semrel:
  image: ghcr.io/SemRels/semrel:latest-alpine
  stage: release
  script:
    - semrel release --gitlab-dotenv semrel.env
  artifacts:
    reports:
      dotenv: semrel.env

Environment variables

The container inherits all environment variables from the host or CI job. Pass secrets via -e or CI secret management:

Variable	Required	Description
GITHUB_TOKEN	For GitHub provider	GitHub API token
GITLAB_TOKEN	For GitLab provider	GitLab API token
SEMREL_DRY_RUN	No	Set to true to simulate

Workspace mounting

semrel operates on the current working directory. Mount your repository to /workspace:

docker run --rm \
  -v "$(pwd):/workspace" \
  -w /workspace \
  -e GITHUB_TOKEN="$GITHUB_TOKEN" \
  ghcr.io/SemRels/semrel:latest-alpine release

Version pinning

Pin to a specific version for reproducible builds:

ghcr.io/SemRels/semrel:1.0.0-alpine