Artifact migration ignores job logs

Summary

rake gitlab:artifacts:migrate migrates artifact files and metadata, but not job logs that are saved as artifact.

Steps to reproduce

• Setup object storage for artifacts
• Check that new logs are saved into the object storage
• Run rake gitlab:artifacts:migrate
• Check location of old logs, which are still on the filesystem and location in DB did not change

Example Project

This is running GitLab 11.1.4

What is the current bug behavior?

The migrator in lib/tasks/gitlab/artifacts/migrate.rake explicitly migrates metadata and files, but does not touch job logs.

What is the expected correct behavior?

All artifacts should be migrated.

Relevant logs and/or screenshots

After a successful migration run, the artifact information looks like this:

salsa=> select job_id, file_type, file, file_store from ci_job_artifacts where job_id = 37798;
 job_id | file_type |     file      | file_store
--------+-----------+---------------+------------
  37798 |         1 | artifacts.zip |          2
  37798 |         2 | metadata.gz   |          2
  37798 |         3 | job.log       |          1
(3 rows)

Possible fixes

(If you can, link to the line of code that might be responsible for the problem)