Update GitHub Actions workflow for build process

.github/workflows/build.yml

@@ -30,22 +30,23 @@ jobs:
     steps:
       - name: Prepare environment
         run: |
+          # Lowercase the image uri
           echo "IMAGE_REGISTRY=${IMAGE_REGISTRY,,}" >> ${GITHUB_ENV}
           echo "IMAGE_NAME=${IMAGE_NAME,,}" >> ${GITHUB_ENV}
 
       - name: Checkout
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v5
+        uses: actions/checkout@v4
 
       - name: Mount BTRFS for podman storage
         id: container-storage-action
-        uses: ublue-os/container-storage-action@911baca08baf30c8654933e9e9723cb399892140 # main
+        uses: ublue-os/container-storage-action@main
         continue-on-error: true 
         with:
           target-dir: /var/lib/containers
           mount-opts: compress-force=zstd:2
 
       - name: Image Metadata
-        uses: docker/metadata-action@030e881283bb7a6894de51c315a6bfe6a94e05cf # v5
+        uses: docker/metadata-action@v5
         id: metadata
         with:
           tags: |
@@ -80,7 +81,7 @@ jobs:
 
       - name: Build Image
         id: build_image
-        uses: redhat-actions/buildah-build@7a95fa7ee0f02d552a32753e7414641a04307056 # v2
+        uses: redhat-actions/buildah-build@v2
         with:
           containerfiles: |
             ./Containerfile
@@ -89,66 +90,30 @@ jobs:
           labels: ${{ steps.metadata.outputs.labels }}
           oci: true
 
-      - name: Apply chunkah optimization
+      # Intelligentes Rechunking auf RPM-Paketbasis mit maximal 128 Layern
-        id: chunkah
+      - name: Apply native bootc rechunking
+        id: rechunk
         run: |
           set -x
-          BASE_IMAGE="${{ env.IMAGE_NAME }}:${{ env.DEFAULT_TAG }}"
+          BASE_IMAGE="localhost/${{ env.IMAGE_NAME }}:${{ env.DEFAULT_TAG }}"
-          
+          mkdir -p ./chunkah-out
-          # 1. Das originale ostree-Label im Runner auslesen und sichern
-          OSTREE_DIFFID=$(podman inspect $BASE_IMAGE --format '{{index .Config.Labels "ostree.final-diffid"}}' 2>/dev/null || echo "")
 
-          # Rootfs extrahieren
+          rpm-ostree compose build-chunked-oci \
-          CONTAINER_ID=$(podman create $BASE_IMAGE)
+            --bootc \
-          mkdir -p ./chunkah-in ./chunkah-out
+            --format-version=2 \
-          podman export $CONTAINER_ID | tar -xf - -C ./chunkah-in
-          podman rm $CONTAINER_ID
-
-          # Die originale Image-Config extrahieren
-          podman inspect $BASE_IMAGE --format '{{json .Config}}' > ./chunkah-config.json
-
-          # Chunkah-Lauf
-          podman run --rm \
-            -v ./chunkah-in:/inputs:z \
-            -v ./chunkah-out:/outputs:z \
-            -v ./chunkah-config.json:/config.json:z \
-            quay.io/coreos/chunkah:latest \
-            build \
-            --config /config.json \
-            --prune /sysroot/ \
             --max-layers 128 \
-            --compressed \
+            --from=$BASE_IMAGE \
-            --output /outputs/image.ociarchive \
+            --output=oci-archive:./chunkah-out/image.ociarchive
-            --rootfs /inputs
-
-          # 2. Das von Chunkah erzeugte Archiv wieder laden und das OCI-Label fest einbrennen
-          if [ ! -z "$OSTREE_DIFFID" ]; then
-            podman load -i ./chunkah-out/image.ociarchive
-            
-            # dangling-ID des neuen Images greifen
-            OPT_IMAGE_ID=$(podman images --filter "dangling=true" --format "{{.ID}}" | head -n 1)
-            
-            # Ein modifiziertes OCI-Image mit Buildah erstellen (erhält die OCI-Struktur exakt aufrecht)
-            BUILDAH_CONTAINER=$(buildah from $OPT_IMAGE_ID)
-            buildah config --label "ostree.final-diffid=$OSTREE_DIFFID" $BUILDAH_CONTAINER
-            
-            # Altes Archiv löschen und durch das final gelabelte OCI-Archiv ersetzen
-            rm ./chunkah-out/image.ociarchive
-            buildah commit --rm $BUILDAH_CONTAINER oci-archive:./chunkah-out/image.ociarchive
-            
-            # Lokalen Speicher aufräumen
-            podman rmi $OPT_IMAGE_ID || true
-          fi
 
       - name: Login to GitHub Container Registry
-        uses: docker/login-action@4907a6ddec9925e35a0a9e82d7399ccc52663121 # v3
+        uses: docker/login-action@v3
         if: github.event_name != 'pull_request' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch)
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - name: Push to GHCR via Skopeo
+      - name: Push to GHCR via Skopeo (with ZSTD Compression)
         if: github.event_name != 'pull_request' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch)
         run: |
           set -x
@@ -156,7 +121,7 @@ jobs:
           export REGISTRY_AUTH_FILE=$HOME/.docker/config.json
           REGISTRY_PATH="${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_NAME }}"
 
-          # Loop über alle Tags
+          # Loop über alle generierten Tags aus dem Metadata-Schritt
           for tag in ${{ steps.metadata.outputs.tags }}; do
             skopeo copy \
               --dest-compress-format=zstd \
@@ -165,18 +130,17 @@ jobs:
               docker://$REGISTRY_PATH:$tag
           done
 
-          # KORREKTUR: Wir fragen den echten, finalen Digest direkt von GHCR ab
+          # Den echten, von der Registry vergebenen Manifest-Digest abfragen
           FINAL_REGISTRY_DIGEST=$(skopeo inspect docker://$REGISTRY_PATH:${{ env.DEFAULT_TAG }} --format '{{.Digest}}')
           echo "REGISTRY_DIGEST=$FINAL_REGISTRY_DIGEST" >> $GITHUB_ENV
 
       - name: Install Cosign
-        uses: sigstore/cosign-installer@6f9f17788090df1f26f669e9d70d6ae9567deba6 # v4.1.2
+        uses: sigstore/cosign-installer@v4
         if: github.event_name != 'pull_request' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch)
       
       - name: Sign container image
         if: github.event_name != 'pull_request' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch)
         run: |
-          # Signiert den exakten, von der Registry bestätigten Digest
           cosign sign -y --key env://COSIGN_PRIVATE_KEY "${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_NAME }}@${{ env.REGISTRY_DIGEST }}"
         env:
           COSIGN_EXPERIMENTAL: false