chore: Ensure snapshots are pushed to registry

.github/workflows/ci-snapshot-cli.yaml

@@ -19,6 +19,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           fetch-depth: 0 # required for tag metadata
+          sparse-checkout: cmd/nrdot-collector-builder
 
       - name: Setup Go
         uses: actions/setup-go@v5
@@ -51,11 +52,82 @@ jobs:
       - name: Publish alpha with GoReleaser
         id: goreleaser
         uses: goreleaser/goreleaser-action@v6
-        if: ${{ !env.ACT && github.ref_name == 'main' && github.event_name == 'push' }}
         with:
           distribution: goreleaser
           version: "~> v2"
           args: --snapshot --clean
           workdir: cmd/nrdot-collector-builder
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Login to GitHub Container Registry for manifests
+        uses: docker/login-action@v3
+        if: ${{ !env.ACT }}
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract and Publish Docker Manifests
+        shell: bash
+        if: ${{ !env.ACT && (github.ref_name == 'main' && github.event_name == 'push' || github.event_name == 'workflow_dispatch') }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          # Extract Docker image names and digests
+          DOCKER_IMAGES=$(echo '${{ steps.goreleaser.outputs.artifacts }}' | jq -r '.[] | select(.type=="Docker Image")')
+
+          # Create temporary files to store grouped data
+          mkdir -p ${{ runner.temp }}/manifest_groups
+          rm -f ${{ runner.temp }}/manifest_groups/*
+
+          # Convert to an array of objects for iteration
+          echo "$DOCKER_IMAGES" | jq -c '.' | while read -r image_object; do
+            # Extract image name and architecture
+            name=$(echo "$image_object" | jq -r '.name')
+            goarch=$(echo "$image_object" | jq -r '.goarch')
+
+            # Extract the base name and tag
+            base_name=$(echo "$name" | cut -d ':' -f 1)
+            tag=$(echo "$name" | cut -d ':' -f 2)
+
+            # Extract base tag (without architecture suffix)
+            base_tag=$(echo "$tag" | cut -d '-' -f 1)
+
+            echo "Processing image: $name (arch: $goarch)"
+            echo "  Base name: $base_name"
+            echo "  Base tag: $base_tag"
+
+            # Use files to store the grouped data
+            # Create a file named after the base_tag and append the image name to it
+            echo "$name" >> "${{ runner.temp }}/manifest_groups/$base_tag"
+          done
+
+          # Now create manifests for each group
+          echo "Creating Docker manifests..."
+          for group_file in ${{ runner.temp }}/manifest_groups/*; do
+            # Extract base_tag from filename
+            base_tag=$(basename "$group_file")
+
+            # Read all images for this tag
+            images=$(cat "$group_file" | tr '\n' ' ')
+
+            # Get base name from the first image
+            first_image=$(echo "$images" | awk '{print $1}')
+            base_name=$(echo "$first_image" | cut -d ':' -f 1)
+
+            # Create manifest name (base name + base tag without arch)
+            manifest_name="${base_name}:${base_tag}"
+
+            echo "Creating manifest: $manifest_name"
+            echo "  With images: $images"
+
+            # Create and push the manifest
+            # Uncomment these lines when you're ready to execute them
+            docker manifest create "$manifest_name" $images
+            docker manifest push "$manifest_name"
+          done
+
+          # Clean up temporary files
+          rm -rf ${{ runner.temp }}/manifest_groups
+