ci: Add flock to openapi spec upload (#11381)

* Add flock to openapi spec upload

Prevents a race condition if two PRs are merged in very quick
succession.

* Remove lock at the end

* Revert "Remove lock at the end"

This reverts commit a7baafd10e3c1bc47304f05c93ac4864e622e5e0.

* Correct incorrect comments

* Exit with an error if flock fails

.github/workflows/ci-openapi.yml

@@ -174,6 +174,8 @@ jobs:
           debug: false
           script_stop: false
           script: |
+            (
+            flock -x -w 300 200 || exit 1
             TGT_DIR="/srv/repository/main/openapi"
             LAST_SPEC="$( ls -lt ${TGT_DIR}/unstable/ | grep 'jellyfin-openapi' | head -1 | awk '{ print $NF }' )"
             # If new and previous spec don't differ (diff retcode 0), remove incoming and finish
@@ -187,10 +189,11 @@ jobs:
             sudo rm ${TGT_DIR}/jellyfin-openapi-unstable_previous.json
             # Move current jellyfin-openapi-unstable.json symlink to jellyfin-openapi-unstable_previous.json
             sudo mv ${TGT_DIR}/jellyfin-openapi-unstable.json ${TGT_DIR}/jellyfin-openapi-unstable_previous.json
-            # Create new jellyfin-openapi-stable.json symlink
+            # Create new jellyfin-openapi-unstable.json symlink
             sudo ln -s unstable/jellyfin-openapi-${{ env.JELLYFIN_VERSION }}.json ${TGT_DIR}/jellyfin-openapi-unstable.json
-            # Check that the previous openapi spec is correct
+            # Check that the previous openapi unstable spec link is correct
             if [[ "$( readlink ${TGT_DIR}/jellyfin-openapi-unstable_previous.json )" != "unstable/${LAST_SPEC}" ]]; then
                 sudo rm ${TGT_DIR}/jellyfin-openapi-unstable_previous.json
                 sudo ln -s unstable/${LAST_SPEC} ${TGT_DIR}/jellyfin-openapi-unstable_previous.json
             fi
+            ) 200>/run/openapi-unstable.lock