• What are Audit Events?
• Audit Event Schemas
• How to instrument new Audit Events
  • Using block to record multiple events
  • Using standard method call to record single event
  • Data volume considerations
• Audit Event instrumentation flows
  • Using block to record multiple events
  • Using standard method call to record single event
• Event streaming

Audit Event Guide

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.

Audit Event Schemas

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

How to instrument new Audit Events

There are three ways of instrumenting audit events:

• Create a new class in ee/lib/ee/audit/ and extend AuditEventService
• Call AuditEventService after a successful action
• Call Gitlab::Audit::Auditor.audit passing an action block

This inconsistency leads to unexpected bugs, increases maintainer effort, and worsens the developer experience. Therefore, we suggest you use Gitlab::Audit::Auditor to instrument new audit events.

With new 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/manage/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.

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.

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

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.