.github/workflows/build: add github-actions building action

.github/workflows/build.yml

@@ -0,0 +1,63 @@
+name: Build images
+
+on: push
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository_owner }}/git-annex
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Log in to the Container registry
+        uses: docker/login-action@65b78e6e13532edd9afa3aa52ac7964289d1a9c1
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@9ec57ed1fcdbf14dcef7dfbe97b2010124a938b7
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+      - name: Build and push Docker image
+        uses: docker/build-push-action@f2a1d5e99d037542a71f64918e516c093c6f3fc4
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+
+      - name: Apptainer setup
+        uses: eWaterCycle/setup-apptainer@v2
+        with:
+          apptainer-version: 1.1.2
+
+      - name: Apptainer build
+        run: |
+          apptainer build git-annex.sif docker-daemon://${{ steps.meta.outputs.tags }}
+
+      - name: Apptainer test
+        run: |
+          ./git-annex.sif version
+
+      - name: Upload Apptainer artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: git-annex.sif
+          path: git-annex.sif
+
+#      - name: Build and push Docker image
+#        uses: docker/build-push-action@f2a1d5e99d037542a71f64918e516c093c6f3fc4
+#        with:
+#          context: .
+#          push: true
+#          tags: ${{ steps.meta.outputs.tags }}
+#          labels: ${{ steps.meta.outputs.labels }}