Audit event development guidelines

This guide provides an overview of how Audit Events work, and how to instrument new audit events.

What are Audit Events?

Audit Events are a tool for GitLab owners and administrators to view records of important actions performed across the application.

What should not be Audit Events?

While any events could trigger an Audit Event, not all events should. In general, events that are not good candidates for audit events are:

• Not attributable to one specific user.
• Not of specific interest to an administrator or owner persona.
• Are tracking information for product feature adoption.
• Are covered in the direction page's discussion on what is not planned.

If you have any questions, please reach out to @gitlab-org/govern/compliance to see if an Audit Event, or some other approach, may be best for your event.

Audit Event Schemas

To instrument an audit event, the following attributes should be provided:

How to instrument new Audit Events

1. Create a YAML type definition for the new audit event.
2. Call Gitlab::Audit::Auditor.audit, passing an action block.

The following ways of instrumenting audit events are deprecated:

• Create a new class in ee/lib/ee/audit/ and extend AuditEventService
• Call AuditEventService after a successful action

With Gitlab::Audit::Auditor service, we can instrument audit events in two ways:

• Using block for multiple events.
• Using standard method call for single events.

Using block to record multiple events

This method is useful when events are emitted deep in the call stack.

For example, we can record multiple audit events when the user updates a merge request approval rule. As part of this user flow, we would like to audit changes to both approvers and approval groups. In the initiating service (for example, MergeRequestRuleUpdateService), we can wrap the execute call as follows:

# in the initiating service
audit_context = {
  name: 'update_merge_approval_rule',
  author: current_user,
  scope: project_alpha,
  target: merge_approval_rule,
  message: 'Attempted to update an approval rule'
}

::Gitlab::Audit::Auditor.audit(audit_context) do
  service.execute
end

In the model (for example, ApprovalProjectRule), we can push audit events on model callbacks (for example, after_save or after_add).

# in the model
include Auditable

def audit_add(model)
  push_audit_event('Added an approver on Security rule')
end

def audit_remove(model)
  push_audit_event('Removed an approver on Security rule')
end

This method does not support actions that are asynchronous, or span across multiple processes (for example, background jobs).

Using standard method call to record single event

This method allows recording single audit event and involves fewer moving parts.

if merge_approval_rule.save
  audit_context = {
    name: 'create_merge_approval_rule',
    author: current_user,
    scope: project_alpha,
    target: merge_approval_rule,
    message: 'Created a new approval rule',
    created_at: DateTime.current # Useful for pre-dating an audit event when created asynchronously.
  }

  ::Gitlab::Audit::Auditor.audit(audit_context)
end

Data volume considerations

Because every audit event is persisted to the database, consider the amount of data we expect to generate, and the rate of generation, for new audit events. For new audit events that will produce a lot of data in the database, consider adding a streaming-only audit event instead. If you have questions about this, feel free to ping @gitlab-org/govern/compliance/backend in an issue or merge request.

Audit Event instrumentation flows

The two ways we can instrument audit events have different flows.

Using block to record multiple events

We wrap the operation block in a Gitlab::Audit::Auditor which captures the initial audit context (that is, author, scope, target) object that are available at the time the operation is initiated.

Extra instrumentation is required in the interacted classes in the chain with Auditable mixin to add audit events to the Audit Event queue via Gitlab::Audit::EventQueue.

The EventQueue is stored in a local thread via SafeRequestStore and then later extracted when we record an audit event in Gitlab::Audit::Auditor.

skinparam shadowing false
skinparam BoxPadding 10
skinparam ParticipantPadding 20

participant "Instrumented Class" as A
participant "Audit::Auditor" as A1 #LightBlue
participant "Audit::EventQueue" as B #LightBlue
participant "Interacted Class" as C
participant "AuditEvent" as D

A->A1: audit <b>{ block }
activate A1
A1->B: begin!
A1->C: <b>block.call
activate A1 #FFBBBB
activate C
C-->B: push [ message ]
C-->A1: true
deactivate A1
deactivate C
A1->B: read
activate A1 #FFBBBB
activate B
B-->A1: [ messages ]
deactivate B
A1->D: bulk_insert!
deactivate A1
A1->B: end!
A1-->A:
deactivate A1

Using standard method call to record single event

This method has a more straight-forward flow, and does not rely on EventQueue and local thread.

skinparam shadowing false
skinparam BoxPadding 10
skinparam ParticipantPadding 20

participant "Instrumented Class" as A
participant "Audit::Auditor" as B #LightBlue
participant "AuditEvent" as C

A->B: audit
activate B
B->C: bulk_insert!
B-->A:
deactivate B

In addition to recording to the database, we also write these events to a log file.

Event type definitions

Introduced in GitLab 15.4.

All new audit events must have a type definition stored in config/audit_events/types/ that contains a single source of truth for every auditable event in GitLab.

Add a new audit event type

To add a new audit event type:

1. Create the YAML definition. You can either:
   • Use the bin/audit-event-type CLI to create the YAML definition automatically.
   • Perform manual steps to create a new file in config/audit_events/types/ with the filename matching the name of the event type. For example, a definition for the event type triggered when a user is added to a project might be stored in config/audit_events/types/project_add_user.yml.
2. Add contents to the file that conform to the schema defined in config/audit_events/types/type_schema.json.
3. Ensure that all calls to Gitlab::Audit::Auditor use the name defined in your file.

Schema

Event streaming

All events where the entity is a Group or Project are recorded in the audit log, and also streamed to one or more event streaming destinations. When the entity is a:

• Group, events are streamed to the group's root ancestor's event streaming destinations.
• Project, events are streamed to the project's root ancestor's event streaming destinations.

You can add streaming-only events that are not stored in the GitLab database. This is primarily intended to be used for actions that generate a large amount of data. See this merge request for an example. This feature is under heavy development. Follow the parent epic for updates on feature development.

I18N and the Audit Event :message attribute

We intentionally do not translate audit event messages because translated messages would be saved in the database and served to users, regardless of their locale settings.

This could mean, for example, that we use the locale for the currently authenticated user to record an audit event message and stream the message to an external streaming destination in the wrong language for that destination. Users could find that confusing.