在root用户下，执行

[root@localhost ~]#  gitlab-rails console production

-------------------------------------------------------------------------------------
 GitLab:       11.0.4 (edb037c)
 GitLab Shell: 7.1.4
 postgresql:   9.6.8
-------------------------------------------------------------------------------------
Loading production environment (Rails 4.2.10)

　　

<em id="__mceDel">2.获得用户数据，修改用户密码</em>

irb(main):001:0> 
irb(main):002:0* user = User.where(id: 1).first
=> #<User id:1 @root>
irb(main):003:0> user.password = 12345678
=> 12345678
irb(main):004:0> user.password_confirmation = 12345678
=> 12345678
irb(main):005:0>  user.save!
Enqueued ActionMailer::DeliveryJob (Job ID: 0be0d09b-0be2-4edf-be6f-b0c7d5c92e83) to Sidekiq(mailers) with arguments: "DeviseMailer", "password_change", "deliver_now", gid://gitlab/User/1
=> true
irb(main):006:0> quit

　　

另：gitlab默认用户名密码 root 5ivel!fe