Hi rocky123456703948398, welcome to the GitLab Community Forum!
The best way to migrate from one GitLab instance to another is to back up the normal gitlab instance and then restore it on the new one (using docker).
https://docs.gitlab.com/ee/user/project/import/#migrating-between-two-self-managed-gitlab-instances
Create backup of current instance
Install GitLab version 12.4.3 using docker on the new system:
https://docs.gitlab.com/omnibus/docker/
sudo docker run --detach \
--hostname gitlab.example.com \
--publish 443:443 --publish 80:80 --publish 22:22 \
--name gitlab \
--restart always \
--volume $GITLAB_HOME/gitlab/config:/etc/gitlab \
--volume $GITLAB_HOME/gitlab/logs:/var/log/gitlab \
--volume $GITLAB_HOME/gitlab/data:/var/opt/gitlab \
gitlab/gitlab-ee:12.4.2-ee.0
Copy backup, config, and secrets file to GitLab docker container.
Exec into docker container
https://docs.gitlab.com/omnibus/docker/#configure-gitlab
restore from backup https://docs.gitlab.com/ee/raketasks/backup_restore.html#restore
Once you’ve successfully restored from backup in the docker container, you can safely upgrade the new dockerized GitLab to the latest version:
https://docs.gitlab.com/omnibus/docker/#upgrade-gitlab-to-newer-version
I would suggest not running GitLab versions with the -pre
suffix as these are pre-release images that do not get tested as thoroughly as our our official releases.
Having said all of that: We strongly recommend using the Omnibus package installation (instead of docker) since it is quicker to install, easier to upgrade and configure, and it contains features to enhance reliability not found in other methods.
Let us know how it goes , or if you have any additional questions!