deploy: check the books dir from a root container (deploy user cannot traverse /home/stan)

Run #78 skipped the /books mount because [ -d /home/stan/books/library ] runs as
the deploy account, which has no access to /home/stan (0750). Check inside a
container with the dir bind-mounted instead; the mount itself is done by dockerd.

scripts/deploy-remote.sh

@@ -19,13 +19,26 @@ environment_name=production
 image="git.stanrunge.dev/stan/website:$sha"
 compose="$directory/compose.prod.yml"
 compose_files=(-f "$compose")
+# Images built before the repo rename (stan/personal-website -> stan/website) keep
+# their old local name; retag so rollbacks to those SHAs still work.
+legacy_image="git.stanrunge.dev/stan/personal-website:$sha"
+if ! sudo docker image inspect "$image" >/dev/null 2>&1 &&
+  sudo docker image inspect "$legacy_image" >/dev/null 2>&1; then
+  sudo docker tag "$legacy_image" "$image"
+fi
+if ! sudo docker image inspect "$image" >/dev/null 2>&1; then
+  echo "Image $image is not on this host" >&2; exit 1
+fi
 # Book files (ebooks + covers) live on the host and are bind-mounted read-only at /books;
 # the app streams them only to the owner via /trackers/books/files/<id> (no static path).
 # Layout: $books_host_dir/library/<files.path> and $books_host_dir/covers/<works.cover_path>.
 # compose.prod.yml is host-managed, so the mount goes in a generated override file.
 books_host_dir=${BOOKS_HOST_DIR:-/home/stan/books}
 case "$books_host_dir" in /*) ;; *) echo 'BOOKS_HOST_DIR must be absolute' >&2; exit 2 ;; esac
-if [ -d "$books_host_dir/library" ]; then
+# The deploy account can't traverse /home/stan (0750); check from a root container instead.
+if sudo docker run --rm --entrypoint sh \
+  --mount "type=bind,source=$books_host_dir,target=/books,readonly" "$image" \
+  -c 'test -d /books/library' 2>/dev/null; then
   sudo tee "$directory/compose.books.yml" >/dev/null <<YAML
 services:
   app:
@@ -41,16 +54,6 @@ YAML
 else
   echo "No $books_host_dir/library on this host; book files will not be readable" >&2
 fi
-# Images built before the repo rename (stan/personal-website -> stan/website) keep
-# their old local name; retag so rollbacks to those SHAs still work.
-legacy_image="git.stanrunge.dev/stan/personal-website:$sha"
-if ! sudo docker image inspect "$image" >/dev/null 2>&1 &&
-  sudo docker image inspect "$legacy_image" >/dev/null 2>&1; then
-  sudo docker tag "$legacy_image" "$image"
-fi
-if ! sudo docker image inspect "$image" >/dev/null 2>&1; then
-  echo "Image $image is not on this host" >&2; exit 1
-fi
 previous_tag=$(sed -n 's/^IMAGE_TAG=//p' "$directory/.env" | head -n 1)
 switched=0
 rollback() {