Application limits development

This document provides a development guide for contributors to add application limits to GitLab.

Documentation

First of all, you have to gather information and decide which are the different limits that are set for the different GitLab tiers. You also need to coordinate with others to document and communicate those limits.

There is a guide about introducing application limits.

Development

Insert database plan limits

In the plan_limits table, create a new column and insert the limit values. It's recommended to create two separate migration script files.

1. Add a new column to the plan_limits table with non-null default value that represents desired limit, such as:

   add_column(:plan_limits, :project_hooks, :integer, default: 100, null: false)

   Plan limits entries set to 0 mean that limits are not enabled. You should use this setting only in special and documented circumstances.

2. (Optionally) Create the database migration that fine-tunes each level with a desired limit using create_or_update_plan_limit migration helper, such as:

   class InsertProjectHooksPlanLimits < ActiveRecord::Migration[5.2]
     include Gitlab::Database::MigrationHelpers
   
     DOWNTIME = false
   
     def up
       create_or_update_plan_limit('project_hooks', 'default', 0)
       create_or_update_plan_limit('project_hooks', 'free', 10)
       create_or_update_plan_limit('project_hooks', 'bronze', 20)
       create_or_update_plan_limit('project_hooks', 'silver', 30)
       create_or_update_plan_limit('project_hooks', 'gold', 100)
     end
   
     def down
       create_or_update_plan_limit('project_hooks', 'default', 0)
       create_or_update_plan_limit('project_hooks', 'free', 0)
       create_or_update_plan_limit('project_hooks', 'bronze', 0)
       create_or_update_plan_limit('project_hooks', 'silver', 0)
       create_or_update_plan_limit('project_hooks', 'gold', 0)
     end
   end

   Some plans exist only on GitLab.com. This is a no-op for plans that do not exist.

Plan limits validation

Get current limit

Access to the current limit can be done through the project or the namespace, such as:

project.actual_limits.project_hooks

Check current limit

There is one method PlanLimits#exceeded? to check if the current limit is being exceeded. You can use either an ActiveRecord object or an Integer.

Ensures that the count of the records does not exceed the defined limit, such as:

project.actual_limits.exceeded?(:project_hooks, ProjectHook.where(project: project))

Ensures that the number does not exceed the defined limit, such as:

project.actual_limits.exceeded?(:project_hooks, 10)

Limitable concern

The Limitable concern can be used to validate that a model does not exceed the limits. It ensures that the count of the records for the current model does not exceed the defined limit.

You must specify the limit scope of the object being validated and the limit name if it's different from the pluralized model name.

class ProjectHook
  include Limitable

  self.limit_name = 'project_hooks' # Optional as ProjectHook corresponds with project_hooks
  self.limit_scope = :project
end

To test the model, you can include the shared examples.

it_behaves_like 'includes Limitable concern' do
  subject { build(:project_hook, project: create(:project)) }
end

Testing instance-wide limits

Instance-wide features always use default Plan, as instance-wide features do not have license assigned.

class InstanceVariable
  include Limitable

  self.limit_name = 'instance_variables' # Optional as InstanceVariable corresponds with instance_variables
  self.limit_scope = Limitable::GLOBAL_SCOPE
end

Subscription Plans

Self-managed:

• default - Everyone

GitLab.com:

• default - Any system-wide feature
• free - Namespaces and projects with a Free subscription
• bronze- Namespaces and projects with a Bronze subscription
• silver - Namespaces and projects with a Silver subscription
• gold - Namespaces and projects with a Gold subscription

The test environment doesn't have any plans.