Use skopeo for loading the image

.github/workflows/build_containers.yml

@@ -11,25 +11,8 @@ jobs:
       - uses: wimpysworld/nothing-but-nix@main
       - uses: cachix/install-nix-action@v31.3.0
       - name: Build snapbin image
-        run: nix build .#snapbin-image && docker load < ./result
-
-      - name: Log into registry
-        run: echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u ${{ github.actor }} --password-stdin
-
-      - name: Push image
         env:
-          IMAGE_NAME: snapbin
-        run: |
-          IMAGE_ID=ghcr.io/${{ github.repository }}/$IMAGE_NAME
-          # Change all uppercase to lowercase
-          IMAGE_ID=$(echo $IMAGE_ID | tr '[A-Z]' '[a-z]')
-          # Strip git ref prefix from version
-          VERSION=$(echo "${{ github.ref }}" | sed -e 's,.*/\(.*\),\1,')
-          # Strip "v" prefix from tag name
-          [[ "${{ github.ref }}" == "refs/tags/"* ]] && VERSION=$(echo $VERSION | sed -e 's/^v//')
-          # Use Docker `latest` tag convention
-          [ "$VERSION" == "main" ] && VERSION=latest
-          echo IMAGE_ID=$IMAGE_ID
-          echo VERSION=$VERSION
-          docker tag $IMAGE_NAME $IMAGE_ID:$VERSION
-          docker push $IMAGE_ID:$VERSION
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_USERNAME: ${{ github.actor }}
+          GITHUB_REPOSITORY: ${{ github.repository }}
+        run: nix develop --command build-image.sh

flake.nix

@@ -150,6 +150,7 @@
               packages = [
                 pythonDev
                 pkgs.poetry
+                pkgs.skopeo
               ];
               inputsFrom = [
                 config.process-compose."dev-services".services.outputs.devShell

tooling/bin/build-image.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+echo "$GITHUB_TOKEN" | skopeo login ghcr.io --username "$GITHUB_USERNAME" --password-stdin
+result=$(nix build .#snapbin-image --no-link --print-out-paths)
+# ${variabe,,} converts a string to lowercase
+skopeo copy --insecure-policy docker-archive://"$result" docker://"ghcr.io/${GITHUB_REPOSITORY,,}/snapbin:latest"