Fill `file_sha256` values of `ci_job_artifacts` table from object storage
From GitLab %10.6, we started storing
file_256 (Checksum of the
ci_job_artfacts table. Old rows, which had been created before %10.6, do not have values in the column. We should calculate the checksum and fill it into the old rows.
All artifact files on gitlab.com are stored in object storage, and there are no API provided from object storage provider that getting SHA256 checksum. We need to pull the whole data of files into local filestorage, and calculate the SHA256 locally. This is expensive, time consuming and constly (because of the ingress cost from S3 -> GCP). We would need something differently solution.