$DAYJOB needed to migrate from JIRA to Gitlab due to business reasons (not related to the recent outage), so I wrote this issue migration tool [1] to help us preserve our historical data. This tool will copy issues from various JIRA projects to mirrored Gitlab projects (e.g. A jira project named JIRA-PROJECT1 will have its issues migrated to a gitlab project GL-PROJECT1). The tool also migrates issue comments to Gitlab notes and will recreate the existing issue links.YMMV, but this is working well for us. Comments welcomed.
1: https://gitlab.com/jeremygonyea/jira-to-gitlab-miigration-tool