build.yml

name: Build Apptainer Container

on:
  push:
    branches: [main]
    tags: ['*']

env:
  REGISTRY: ghcr.io
  # Hardcoded container name here
  IMAGE_NAME: ${{ github.repository_owner }}/s3cmdc

jobs:
  build-apptainer:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          # fetch-depth: 0 is required for git describe to access the full tag history
          fetch-depth: 0

      - name: Extract SCM versions
        id: scm
        run: |
          # Extracts the nearest tag, number of commits since the tag, and the abbreviated commit hash.
          # Example output: 1.0.1-4-g1a2b3c4. If no tags exist, the commit SHA is returned.
          RAW_VERSION=$(git describe --tags --always)
          
          # Sanitize the string for OCI registry compatibility
          CLEAN_VERSION=$(echo "$RAW_VERSION" | tr '+' '-')
          echo "tag_version=$CLEAN_VERSION" >> "$GITHUB_OUTPUT"

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=raw,value=latest
            type=sha,format=short
            type=raw,value=${{ steps.scm.outputs.tag_version }}

      - name: Setup Apptainer
        uses: eWaterCycle/setup-apptainer@v2
        with:
          apptainer-version: 1.3.1

      - name: Build Apptainer image
        run: |
          sudo apptainer build container.sif containers/s3cmdc.def

      - name: Push Apptainer image to GHCR
        run: |
          echo "${{ secrets.GITHUB_TOKEN }}" | apptainer registry login -u ${{ github.actor }} --password-stdin oras://${{ env.REGISTRY }}
          
          # Clean way to loop through tags even if they have weird spacing
          TAGS="${{ steps.meta.outputs.tags }}"
          for TAG in $TAGS; do
            echo "Pushing to oras://$TAG"
            apptainer push container.sif "oras://$TAG"
          done