docker.yml

# Manual only: run it from the Actions tab when there is something worth publishing.
name: docker

on:
  workflow_dispatch:
    inputs:
      tag:
        description: Image tag to publish
        default: latest

jobs:
  publish:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write # what lets GITHUB_TOKEN push to ghcr.io
    steps:
      - uses: actions/checkout@v4

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

      - uses: docker/setup-buildx-action@v3

      - id: image
        run: echo "ref=ghcr.io/${GITHUB_REPOSITORY,,}" >> "$GITHUB_OUTPUT"

      - uses: docker/build-push-action@v6
        with:
          context: .
          push: true
          tags: |
            ${{ steps.image.outputs.ref }}:${{ inputs.tag }}
            ${{ steps.image.outputs.ref }}:${{ github.sha }}
          cache-from: type=gha
          cache-to: type=gha,mode=max