Integrations development guide (FREE)

This page provides development guidelines for implementing GitLab integrations, which are part of our main Rails project.

Also see our direction page for an overview of our strategy around integrations.

This guide is a work in progress. You're welcome to ping @gitlab-org/ecosystem-stage/integrations if you need clarification or spot any outdated information.

Add a new integration

Define the integration

1. Add a new model in app/models/integrations extending from Integration.

   • For example, Integrations::FooBar in app/models/integrations/foo_bar.rb.
   • For certain types of integrations, you can also build on these base classes:
     • Integrations::BaseChatNotification
     • Integrations::BaseIssueTracker
     • Integrations::BaseMonitoring
     • Integrations::BaseSlashCommands
   • For integrations that primarily trigger HTTP calls to external services, you can also use the Integrations::HasWebHook concern. This reuses the webhook functionality in GitLab through an associated ServiceHook model, and automatically records request logs which can be viewed in the integration settings.

2. Add the integration's underscored name ('foo_bar') to Integration::INTEGRATION_NAMES.

3. Add the integration as an association on Project:

   has_one :foo_bar_integration, class_name: 'Integrations::FooBar'

4. TEMPORARY: Accommodate the current migration to rename "services" to "integrations":

   • Add the integration's camel-cased name ('FooBar') to Gitlab::Integrations::StiType::NAMESPACED_INTEGRATIONS.

Define properties

Integrations can define arbitrary properties to store their configuration with the class method Integration.prop_accessor. The values are stored as an encrypted JSON hash in the integrations.encrypted_properties column.

For example:

module Integrations
  class FooBar < Integration
    prop_accessor :url
    prop_accessor :tags
  end
end

Integration.prop_accessor installs accessor methods on the class. Here we would have #url, #url= and #url_changed?, to manage the url field. Fields stored in Integration#properties should be accessed by these accessors directly on the model, just like other ActiveRecord attributes.

You should always access the properties through their getters, and not interact with the properties hash directly. You must not write to the properties hash, you must use the generated setter method instead. Direct writes to this hash are not persisted.

You should also define validations for all your properties.

Also refer to the section Customize the frontend form below to see how these properties are exposed in the frontend form for the integration.

There is an alternative approach using Integration.data_field, which you may see in other integrations. With data fields the values are stored in a separate table per integration. At the moment we don't recommend using this for new integrations.

Define trigger events

Integrations are triggered by calling their #execute method in response to events in GitLab, which gets passed a payload hash with details about the event.

The supported events have some overlap with webhook events, and receive the same payload. You can specify the events you're interested in by overriding the class method Integration.supported_events in your model.

The following events are supported for integrations:

Event examples

This example defines an integration that responds to commit and merge_request events:

module Integrations
  class FooBar < Integration
    def self.supported_events
      %w[commit merge_request]
    end
  end
end

An integration can also not respond to events, and implement custom functionality some other way:

module Integrations
  class FooBar < Integration
    def self.supported_events
      []
    end
  end
end

Customize the frontend form

The frontend form is generated dynamically based on metadata defined in the model.

By default, the integration form provides:

• A checkbox to enable or disable the integration.
• Checkboxes for each of the trigger events returned from Integration#configurable_events.

You can also add help text at the top of the form by either overriding Integration#help, or providing a template in app/views/shared/integrations/$INTEGRATION_NAME/_help.html.haml.

To add your custom properties to the form, you can define the metadata for them in Integration#fields.

This method should return an array of hashes for each field, where the keys can be:

Additional keys for type: 'checkbox'

Additional keys for type: 'select'

Additional keys for type: 'password'

Frontend form examples

This example defines a required url field, and optional username and password fields:

module Integrations
  class FooBar < Integration
    prop_accessor :url, :username, :password

    def fields
      [
        {
          type: 'text',
          name: 'url',
          title: s_('FooBarIntegration|Server URL'),
          placeholder: 'https://example.com/',
          required: true
        },
        {
          type: 'text',
          name: 'username',
          title: s_('FooBarIntegration|Username'),
        },
        {
          type: 'password',
          name: 'password',
          title: s_('FoobarIntegration|Password'
          non_empty_password_title: s_('FooBarIntegration|Enter new password')
        }
      ]
    end
  end
end

Expose the integration in the API

REST API

To expose the integration in the REST API:

1. Add the integration's class (::Integrations::FooBar) to API::Helpers::IntegrationsHelpers.integration_classes.
2. Add all properties that should be exposed to API::Helpers::IntegrationsHelpers.integrations.
3. Update the reference documentation in doc/api/integrations.md, add a new section for your integration, and document all properties.

You can also refer to our REST API style guide.

GraphQL API

Integrations use the Types::Projects::ServiceType type by default, which only exposes the type and active properties.

To expose additional properties, you can write a class implementing ServiceType:

# in app/graphql/types/project/services/foo_bar_service_type.rb
module Types
  module Projects
    module Services
      class FooBarServiceType < BaseObject
        graphql_name 'FooBarService'
        implements(Types::Projects::ServiceType)
        authorize :read_project

        field :frobinity,
            GraphQL::Types::Float,
            null: true,
            description: 'The level of frobinity.'

        field :foo_label,
            GraphQL::Types::String,
            null: true,
            description: 'The foo label to apply.'
      end
    end
  end
end

Each property you want to expose should have a field defined for it. You can also expose any public instance method of the integration.

Contact a member of the Integrations team to discuss the best authorization.

Reference documentation for GraphQL is automatically generated.

You can also refer to our GraphQL API style guide.

Availability of integrations

By default, integrations are available on the project, group, and instance level. Most integrations only act in a project context, but can be still configured from the group and instance levels.

For some integrations it can make sense to only make it available on the project level. To do that, the integration must be removed from Integration::INTEGRATION_NAMES and added to Integration::PROJECT_SPECIFIC_INTEGRATION_NAMES instead.

When developing a new integration, we also recommend you gate the availability behind a feature flag in Integration.available_integration_names.

Documentation

You can provide help text in the integration form, including links to off-site documentation, as described above in Customize the frontend form. Refer to our usability guidelines for help text.

For more detailed documentation, provide a page in doc/user/project/integrations, and link it from the Integrations overview.

You can also refer to our general documentation guidelines.

Testing

It is often sufficient to add tests for the integration model in spec/models/integrations, and a factory with example settings in spec/factories/integrations.rb.

Each integration is also tested as part of generalized tests. For example, there are feature specs that verify that the settings form is rendering correctly for all integrations.

If your integration implements any custom behavior, especially in the frontend, this should be covered by additional tests.

You can also refer to our general testing guidelines.

Internationalization

All UI strings should be prepared for translation by following our internationalization guidelines.

The strings should use the integration name as namespace, for example, s_('FooBarIntegration|My string').

Ongoing migrations and refactorings

The Integrations team is in the process of some larger migrations that developers should be aware of.

Rename "services" to "integrations"

The "integrations" in GitLab were historically called "services", which frequently caused confusion with our "service" classes in app/services. We sometimes also called them "project services" because they were initially only available on projects, which is not the case anymore.

We decided to change the naming from "services" and "project services" to "integrations". This refactoring is an ongoing effort, and there are still references to the old names in some places.

Developers should be especially aware that we still use the old class names for the STI column integrations.type. For example, a class Integrations::FooBar still stores the old name FooBarService in the database. This mapping is handled via Gitlab::Integrations::StiType and should be mostly transparent to the rest of the app.

Consolidate integration settings

We want to unify the way integration properties are defined.

Integration examples

You can refer to these issues for examples of adding new integrations:

• Datadog: Metrics collector, similar to the Prometheus integration.
• EWM/RTC: External issue tracker.
• Shimo: External wiki, similar to the Confluence and External Wiki integrations.
• Webex Teams: Chat notifications.
• ZenTao: External issue tracker with custom issue views, similar to the Jira integration.