一、事情起因
因機房服務器即將到期，需要將即將到期的服務器遷移至雲上，遷移之前沒有查看老環境的Gitlab是什么版本，直接裝的Gitlab社區版，做數據導入時提示版本錯誤：
[root@vpn-server-001 devops]# gitlab-rake gitlab:backup:restore RAILS_ENV=production BACKUP=1531072861
Unpacking backup ... done
GitLab version mismatch:
Your current GitLab version (11.0.2) differs from the GitLab version in the backup!
Please switch to the following version and try again:
version: 8.9.5
Hint: git checkout v8.9.5
此時去查看老環境的gitlab版本：
[root@git-server yum.repos.d]# gitlab-rake gitlab:env:info
System information
System:
Current User: git
Using RVM: no
Ruby Version: 2.1.8p440
Gem Version: 2.5.1
Bundler Version:1.10.6
Rake Version: 10.5.0
Sidekiq Version:4.1.2
GitLab information
Version: 8.9.5 #發現是8.9.5的
Revision: f6ab19d
Directory: /opt/gitlab/embedded/service/gitlab-rails
DB Adapter: postgresql
URL: http://gitlab.zlkjbj.cn
HTTP Clone URL: http://gitlab.zlkjbj.cn/some-group/some-project.git
SSH Clone URL: git@gitlab.zlkjbj.cn:some-group/some-project.git
Using LDAP: no
Using Omniauth: no
GitLab Shell
Version: 3.0.0
Repositories: /data/git-data/repositories
Hooks: /opt/gitlab/embedded/service/gitlab-shell/hooks/
Git: /opt/gitlab/embedded/bin/git
查看新環境的Gitlab版本：
[root@server-001 ~]# gitlab-rake gitlab:env:info
System information
System:
Current User: git
Using RVM: no
Ruby Version: 2.4.4p296
Gem Version: 2.7.6
Bundler Version:1.16.2
Rake Version: 12.3.1
Redis Version: 3.2.11
Git Version: 2.17.1
Sidekiq Version:5.1.3
Go Version: unknown
GitLab information
Version: 11.0.2 #新環境的版本為11.0.2
Revision: d9540ee
Directory: /opt/gitlab/embedded/service/gitlab-rails
DB Adapter: postgresql
URL: http://114.115.181.98
HTTP Clone URL: http://114.115.181.98/some-group/some-project.git
SSH Clone URL: ssh://git@114.115.181.98:52113/some-group/some-project.git
Using LDAP: no
Using Omniauth: no
GitLab Shell
Version: 7.1.4
Repository storage paths:
- default: /var/opt/gitlab/git-data/repositories
Hooks: /opt/gitlab/embedded/service/gitlab-shell/hooks
Git: /opt/gitlab/embedded/bin/git
知道問題后，下面是將新環境的Gitlab替換為8.9.5的版本：
yum remove -y gitlab-ce #卸載新環境的Gitlab yum install -y gitlab-ce-8.9.5 #指定安裝8.9.5的版本的gitlab
然后做導入操作（需要將備份文件放到指定的目錄下）：
# gitlab-rake gitlab:backup:restore BACKUP=1531072861 #1531072861為你需要恢復備份的時間戳，文件名為：1531072861_gitlab_backup.tar 這種形式
然后登陸Gitlab界面查看數據即可！！！
二、問題解決
遷移后訪問首頁沒問題，但是訪問項目時會報500的錯誤，是gitlab數據遷移時的一個缺陷。日志如下：
Started GET "/davidb/workflow-test2" for 127.0.0.1 at 2016-05-25 11:18:10 -0500
Processing by ProjectsController#show as HTML
Parameters: {"namespace_id"=>"davidb", "id"=>"workflow-test2"}
Completed 500 Internal Server Error in 242ms (ActiveRecord: 7.4ms)
OpenSSL::Cipher::CipherError (bad decrypt):
app/models/project.rb:379:in `import_url'
app/models/project.rb:409:in `external_import?'
app/models/project.rb:401:in `import?'
app/models/project.rb:417:in `import_in_progress?'
app/controllers/projects_controller.rb:93:in `show'
lib/gitlab/middleware/go.rb:16:in `call'
解決辦法：
1、覆蓋原來gitlab的 db_key_base 到新的gitlab
db_key_base 位置在 /etc/gitlab/gitlab-secrets.json
2、EE版本執行命令
sudo gitlab-rails runner "Project.where(mirror: false).where.not(import_url: nil).each { |p| p.import_data.destroy if p.import_data }"
CE版本執行命令
sudo gitlab-rails runner "Project.where.not(import_url: nil).each { |p| p.import_data.destroy if p.import_data }"