fix(build-nix-image): handle 403/404 for new images

Signed-off-by: Cameron Smith <cameron.ray.smith@gmail.com>

Author: cameronraysmith

.github/actions/build-nix-image/action.yml

@@ -100,23 +100,18 @@ runs:
         echo "Using Git SHA Short: $GIT_SHA_SHORT"
         FQN_GIT_SHA="${{ inputs.imageFQN }}:$GIT_SHA"
 
-        # # This section currently doesn't account for the case where
-        # # a new image is being pushed to a repository for the first time.
-        # # As a workaround, when creating new images from this action,
-        # # the follwing four commented lines can be toggled with those below
-        # # them.
-        # echo "Image FQN with Git SHA: $FQN_GIT_SHA"
-        # df -h
-        # echo "Image $FQN_GIT_SHA does not exist. Building."
-        # nix-channel --update
-        # podman manifest inspect docker.io/library/flocken:latest || true
-        # podman manifest inspect quay.io/flocken:latest || true
-        # ${{ inputs.nixCommand }}
+        echo "Image FQN with Git SHA: $FQN_GIT_SHA"
+        df -h
 
+        # Check if image exists,
+        # handle both 404 (manifest unknown) and 403 (forbidden) errors
+        # which can occur when the image or repository doesn't exist yet
         if SKOPEO_OUTPUT=$(skopeo inspect "docker://$FQN_GIT_SHA" 2>&1); then
           echo "Image $FQN_GIT_SHA already exists. Skipping build."
         else
-          if echo "$SKOPEO_OUTPUT" | grep -q 'manifest unknown'; then
+          if echo "$SKOPEO_OUTPUT" | grep -q 'manifest unknown' || \
+             echo "$SKOPEO_OUTPUT" | grep -q 'invalid status code from registry 403' || \
+             echo "$SKOPEO_OUTPUT" | grep -q 'invalid status code from registry 404'; then
             echo "Image $FQN_GIT_SHA does not exist. Building."
             nix-channel --update
             podman manifest inspect docker.io/library/flocken:latest || true