Guidelines for implementing Enterprise Edition features

  • Write the code and the tests.: As with any code, EE features should have good test coverage to prevent regressions.
  • Write documentation.: Add documentation to the doc/ directory. Describe the feature and include screenshots, if applicable. Indicate what editions the feature applies to.
  • Submit a MR to the www-gitlab-com project.: Add the new feature to the EE features list.

Act as SaaS

When developing locally, there are times when you need your instance to act like the SaaS version of the product. In those instances, you can simulate SaaS by exporting an environment variable as seen below:

export GITLAB_SIMULATE_SAAS=1

There are many ways to pass an environment variable to your local GitLab instance. For example, you can create a env.runit file in the root of your GDK with the above snippet.

Act as CE when unlicensed

Since the implementation of GitLab CE features to work with unlicensed EE instance GitLab Enterprise Edition should work like GitLab Community Edition when no license is active. So EE features always should be guarded by project.feature_available? or group.licensed_feature_available? (or License.feature_available? if it is a system-wide feature).

Frontend features should be guarded by pushing a flag from the backend by using push_licensed_feature, and checked using this.glFeatures.someFeature in the frontend. For example:

<script>
import glFeatureFlagMixin from '~/vue_shared/mixins/gl_feature_flags_mixin';

export default {
  mixins: [glFeatureFlagMixin()],
  components: {
    EEComponent: () => import('ee_component/components/test.vue'),
  },
  computed: {
    shouldRenderComponent() {
      return this.glFeatures.myEEFeature;
    }
  },
};
</script>

<template>
  <div>
    <ee-component v-if="shouldRenderComponent"/>
  </div>
</template>

Look in ee/app/models/license.rb for the names of the licensed features.

CE specs should remain untouched as much as possible and extra specs should be added for EE. Licensed features can be stubbed using the spec helper stub_licensed_features in EE::LicenseHelpers.

You can force GitLab to act as CE by either deleting the ee/ directory or by setting the FOSS_ONLY environment variable to something that evaluates as true. The same works for running tests (for example FOSS_ONLY=1 yarn jest).

Running feature specs as CE

When running feature specs as CE, you should ensure that the edition of backend and frontend match. To do so:

  1. Set the FOSS_ONLY=1 environment variable:

    export FOSS_ONLY=1
    
  2. Start GDK:

    gdk start
    
  3. Run feature specs:

    bin/rspec spec/features/<path_to_your_spec>
    

CI pipelines in a FOSS context

By default, merge request pipelines for development run in an EE-context only. If you are developing features that differ between FOSS and EE, you may wish to run pipelines in a FOSS context as well.

To run pipelines in both contexts, add the ~"pipeline:run-as-if-foss" label to the merge request.

See the As-if-FOSS jobs pipelines documentation for more information.

Separation of EE code

All EE code should be put inside the ee/ top-level directory. The rest of the code should be as close to the CE files as possible.

EE-only features

If the feature being developed is not present in any form in CE, we don’t need to put the code under the EE namespace. For example, an EE model could go into: ee/app/models/awesome.rb using Awesome as the class name. This is applied not only to models. Here’s a list of other examples:

  • ee/app/controllers/foos_controller.rb
  • ee/app/finders/foos_finder.rb
  • ee/app/helpers/foos_helper.rb
  • ee/app/mailers/foos_mailer.rb
  • ee/app/models/foo.rb
  • ee/app/policies/foo_policy.rb
  • ee/app/serializers/foo_entity.rb
  • ee/app/serializers/foo_serializer.rb
  • ee/app/services/foo/create_service.rb
  • ee/app/validators/foo_attr_validator.rb
  • ee/app/workers/foo_worker.rb
  • ee/app/views/foo.html.haml
  • ee/app/views/foo/_bar.html.haml

This works because for every path that is present in CE’s eager-load/auto-load paths, we add the same ee/-prepended path in config/application.rb. This also applies to views.

Testing EE-only features

To test an EE class that doesn’t exist in CE, create the spec file as you normally would in the ee/spec directory, but without the second ee/ subdirectory. For example, a class ee/app/models/vulnerability.rb would have its tests in ee/spec/models/vulnerability_spec.rb.

EE features based on CE features

For features that build on existing CE features, write a module in the EE namespace and inject it in the CE class, on the last line of the file that the class resides in. This makes conflicts less likely to happen during CE to EE merges because only one line is added to the CE class - the line that injects the module. For example, to prepend a module into the User class you would use the following approach:

class User < ActiveRecord::Base
  # ... lots of code here ...
end

User.prepend_mod

Do not use methods such as prepend, extend, and include. Instead, use prepend_mod, extend_mod, or include_mod. These methods will try to find the relevant EE module by the name of the receiver module, for example;

module Vulnerabilities
  class Finding
    #...
  end
end

Vulnerabilities::Finding.prepend_mod

will prepend the module named ::EE::Vulnerabilities::Finding.

If the extending module does not follow this naming convention, you can also provide the module name by using prepend_mod_with, extend_mod_with, or include_mod_with. These methods take a String containing the full module name as the argument, not the module itself, like so;

class User
  #...
end

User.prepend_mod_with('UserExtension')

Since the module would require an EE namespace, the file should also be put in an ee/ sub-directory. For example, we want to extend the user model in EE, so we have a module called ::EE::User put inside ee/app/models/ee/user.rb.

This is also not just applied to models. Here’s a list of other examples:

  • ee/app/controllers/ee/foos_controller.rb
  • ee/app/finders/ee/foos_finder.rb
  • ee/app/helpers/ee/foos_helper.rb
  • ee/app/mailers/ee/foos_mailer.rb
  • ee/app/models/ee/foo.rb
  • ee/app/policies/ee/foo_policy.rb
  • ee/app/serializers/ee/foo_entity.rb
  • ee/app/serializers/ee/foo_serializer.rb
  • ee/app/services/ee/foo/create_service.rb
  • ee/app/validators/ee/foo_attr_validator.rb
  • ee/app/workers/ee/foo_worker.rb

Testing EE features based on CE features

To test an EE namespaced module that extends a CE class with EE features, create the spec file as you normally would in the ee/spec directory, including the second ee/ subdirectory. For example, an extension ee/app/models/ee/user.rb would have its tests in ee/spec/models/ee/user_spec.rb.

In the RSpec.describe call, use the CE class name where the EE module would be used. For example, in ee/spec/models/ee/user_spec.rb, the test would start with:

RSpec.describe User do
  describe 'ee feature added through extension'
end

Overriding CE methods

To override a method present in the CE codebase, use prepend. It lets you override a method in a class with a method from a module, while still having access the class’s implementation with super.

There are a few gotchas with it:

  • you should always extend ::Gitlab::Utils::Override and use override to guard the overrider method to ensure that if the method gets renamed in CE, the EE override isn’t silently forgotten.
  • when the overrider would add a line in the middle of the CE implementation, you should refactor the CE method and split it in smaller methods. Or create a “hook” method that is empty in CE, and with the EE-specific implementation in EE.
  • when the original implementation contains a guard clause (for example, return unless condition), we cannot easily extend the behavior by overriding the method, because we can’t know when the overridden method (that is, calling super in the overriding method) would want to stop early. In this case, we shouldn’t just override it, but update the original method to make it call the other method we want to extend, like a template method pattern. For example, given this base:

      class Base
        def execute
          return unless enabled?
    
          # ...
          # ...
        end
      end
    

    Instead of just overriding Base#execute, we should update it and extract the behavior into another method:

      class Base
        def execute
          return unless enabled?
    
          do_something
        end
    
        private
    
        def do_something
          # ...
          # ...
        end
      end
    

    Then we’re free to override that do_something without worrying about the guards:

      module EE::Base
        extend ::Gitlab::Utils::Override
    
        override :do_something
        def do_something
          # Follow the above pattern to call super and extend it
        end
      end
    

When prepending, place them in the ee/ specific sub-directory, and wrap class or module in module EE to avoid naming conflicts.

For example to override the CE implementation of ApplicationController#after_sign_out_path_for:

def after_sign_out_path_for(resource)
  current_application_settings.a