Production imports kept aborting with
ActiveRecord::RecordNotUnique on packages_name_key and - on
environments that never got the constraint - silently created
duplicate packages. Root cause: overlapping update_from_deb_repos
runs (scheduled + manual) both do find-by-name then insert; whichever
wins the race aborts the whole run, whichever loses gets a
duplicate if the constraint was missing.
Three things so the mechanism stops being the problem:
- An advisory lock serializes update_from_deb_repos runs. A second
run that finds the lock held simply skips with a warning instead
of racing the first one. The lock is session-scoped, so it is
released automatically when the process exits.
- A per-package rescue for ActiveRecord::RecordNotUnique. If a
create still races (e.g. a package being created by a web upload),
the package is re-fetched and updated instead of aborting the run.
- A real migration for packages_name_key, which previously only
existed where it had been added by hand. From now on db:migrate
creates it everywhere, new databases included.
Also verified with a reproduction: a single sequential run of the
deployed importer against a fresh database (both architectures,
~54k packages) creates zero duplicates.
