5.4 KiB
| stage | group | info |
|---|---|---|
| Enablement | Distribution | To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments |
The Rails Console
The Rails console. provides a way to interact with your GitLab instance from the command line.
WARNING: The Rails console interacts directly with GitLab. In many cases, there are no handrails to prevent you from permanently modifying, corrupting or destroying production data. If you would like to explore the Rails console with no consequences, you are strongly advised to do so in a test environment.
The Rails console is for GitLab system administrators who are troubleshooting a problem or need to retrieve some data that can only be done through direct access of the GitLab application.
Starting a Rails console session
For Omnibus installations
sudo gitlab-rails console
For installations from source
sudo -u git -H bundle exec rails console -e production
For Kubernetes deployments
The console is in the task-runner pod. Refer to our Kubernetes cheat sheet for details.
To exit the console, type: quit.
Output Rails console session history
Enter the following command on the rails console to display your command history.
puts Readline::HISTORY.to_a
You can then copy it to your clipboard and save for future reference.
Using the Rails Runner
If you need to run some Ruby code in the context of your GitLab production
environment, you can do so using the Rails Runner.
When executing a script file, the script must be accessible by the git user.
When the command or script completes, the Rails Runner process finishes. It is useful for running within other scripts or cron jobs for example.
For Omnibus installations
sudo gitlab-rails runner "RAILS_COMMAND"
# Example with a two-line Ruby script
sudo gitlab-rails runner "user = User.first; puts user.username"
# Example with a ruby script file (make sure to use the full path)
sudo gitlab-rails runner /path/to/script.rb
For installations from source
sudo -u git -H bundle exec rails runner -e production "RAILS_COMMAND"
# Example with a two-line Ruby script
sudo -u git -H bundle exec rails runner -e production "user = User.first; puts user.username"
# Example with a ruby script file (make sure to use the full path)
sudo -u git -H bundle exec rails runner -e production /path/to/script.rb
Rails Runner does not produce the same output as the console.
If you set a variable on the console, the console will generate useful debug output such as the variable contents or properties of referenced entity:
irb(main):001:0> user = User.first
=> #<User id:1 @root>
Rails Runner does not do this: you have to be explicit about generating output:
$ sudo gitlab-rails runner "user = User.first"
$ sudo gitlab-rails runner "user = User.first; puts user.username ; puts user.id"
root
1
Some basic knowledge of Ruby will be very useful. Try this 30-minute tutorial for a quick introduction. Rails experience is helpful but not essential.
Troubleshooting Rails Runner
The gitlab-rails command executes Rails Runner using a non-root account and group, by default: git:git.
If the non-root account cannot find the Ruby script filename passed to gitlab-rails runner
you may get a syntax error, not an error that the file couldn't be accessed.
A common reason for this is that the script has been put in the root account's home directory.
runner tries to parse the path and file parameter as Ruby code.
For example:
[root ~]# echo 'puts "hello world"' > ./helloworld.rb
[root ~]# sudo gitlab-rails runner ./helloworld.rb
Please specify a valid ruby command or the path of a script to run.
Run 'rails runner -h' for help.
/opt/gitlab/..../runner_command.rb:45: syntax error, unexpected '.'
./helloworld.rb
^
[root ~]# sudo gitlab-rails runner /root/helloworld.rb
Please specify a valid ruby command or the path of a script to run.
Run 'rails runner -h' for help.
/opt/gitlab/..../runner_command.rb:45: unknown regexp options - hllwrld
[root ~]# mv ~/helloworld.rb /tmp
[root ~]# sudo gitlab-rails runner /tmp/helloworld.rb
hello world
A meaningful error should be generated if the directory can be accessed, but the file cannot:
[root ~]# chmod 400 /tmp/helloworld.rb
[root ~]# sudo gitlab-rails runner /tmp/helloworld.rb
Traceback (most recent call last):
[traceback removed]
/opt/gitlab/..../runner_command.rb:42:in `load': cannot load such file -- /tmp/helloworld.rb (LoadError)
In case you encouter a similar error to this:
[root ~]# sudo gitlab-rails runner helloworld.rb
Please specify a valid ruby command or the path of a script to run.
Run 'rails runner -h' for help.
undefined local variable or method `helloworld' for main:Object
You can either move the file to the /tmp directory or create a new directory onwed by the user git and save the script in that directory as illustrated below:
sudo mkdir /scripts
sudo mv /script_path/helloworld.rb /scripts
sudo chown -R git:git /scripts
sudo chmod 700 /scripts
sudo gitlab-rails runner /scripts/helloworld.rb