Doc: Migrating to packaged CI

doc/README.md

@@ -8,3 +8,4 @@
 + [Runners](runners/README.md)
 + [Permissions](permissions/README.md) User permissions
 + [Rake Tasks](raketasks/README.md) Backup and restore take tasks
++ [Migrating to packaged CI](migration_to_omnibus/README.md)

doc/migration_to_omnibus/README.md

@@ -0,0 +1,29 @@
+## Migrating to packaged CI
+
+Since version 5.1 GitLab CI is shipping as part of the GitLab omnibus package. This guide describes how to migrate GitLab CI from a source installation to an Omnibus package.
+
+### 1. Update GitLab
+
+Update GitLab CI manually to the version that you will install using the omnibus package (at least 7.11). Follow the update [manual for installation from sourse](update/README.md)
+
+### 2. Backup
+
+```
+sudo -u gitlab_ci -H bundle exec rake backup:create RAILS_ENV=production
+```
+
+This command will create a backup file in the tmp folder
+(`/home/gitlab_ci/gitlab_ci/tmp/backups/*_gitlab_ci_backup.tar.gz`). You can read more in the [GitLab CI backup/restore documentation](https://gitlab.com/gitlab-org/gitlab-ci/blob/master/doc/raketasks/backup_restore.md)
+
+### 2. Install a packaged GitLab CI
+
+This process is described in the [instruction for enabling GitLab CI](https://gitlab.com/gitlab-org/omnibus-gitlab/blob/master/doc/gitlab-ci/README.md)
+
+### 4. Restore backup
+
+Put backup file to directory `/var/opt/gitlab/backups`.
+Run the restore command:
+
+```
+sudo gitlab-ci-rake backup:restore
+```