Event Logging

Requirements

• Completed the Server Setup Guide
• An enterprise organization

Azure Queue (Cloud)

The cloud instance of Bitwarden uses Azure Queue and Table Storage to handle events. Here's how this works:

1. A user carries out an action which needs to be logged
2. If the event is client-side (e.g. viewing a password), the client sends details of the event to the Events server project, which then calls EventService. If the event is server-side, the relevant project calls EventService itself.
3. The event is temporarily stored in Azure Queue Storage (which is designed for handling large numbers of messages)
4. The EventsProcessor server project runs a regular batch job to retrieve events from Queue Storage and save them to Table Storage
5. Events are retrieved from Table Storage for viewing

To emulate this locally:

1. Make sure you've installed and setup Azurite, as described in the Server Setup Guide

2. Make sure that the globalSettings:events:connectionString user secret is not set, or has the default value of UseDevelopmentStorage=true

3. Start the Events and EventsProcessor projects using dotnet run or your IDE. (Also ensure you have Api, Identity and your web vault running.)

You should now observe that your enterprise organization is logging events (e.g. when creating an item or inviting a user). These should appear in the Event Logs section of the organization vault.

Azure Storage Explorer lets you inspect the contents of your local Queue and Table Storage and is extremely useful for debugging.

Database storage (Self-hosted)

Self-hosted instances of Bitwarden use an alternative EventService implementation to write event logs directly to the Event table in their database.

To use database storage for events:

1. Run your local development server in a self-hosted configuration (Api, Identity and web vault)
2. Start the Events project using dotnet run or your IDE (note: EventsProcessor is not required for self-hosted)

Distributed events (optional)

Events can be distributed via an AMQP messaging system. This messaging system enables new integrations to subscribe to the events. The system supports either RabbitMQ or Azure Service Bus.

Listener / Handler pattern

The goal of moving to distributed events is to build additional service integrations that consume events. To make it easy to support multiple AMQP services (RabbitMQ and Azure Service Bus), the act of listening to the stream of events is decoupled from the act of responding to an event.

Listeners

• One listener per communication platform (e.g. one for RabbitMQ, one for Azure Service Bus).
• Multiple instances can be configured to run independently, each with its own handler and subscription / queue.
• Perform all the aspects of setup / teardown, subscription, etc. for the messaging platform, but do not directly process any events themselves. Instead, they delegate to the handler with which they are configured.

Handlers

• One handler per integration (e.g. HTTP post or event database repository).
• Completely isolated from and know nothing of the messaging platform in use. This allows them to be freely reused across different communication platforms.
• Perform all aspects of handling an event.
• Allows them to be highly testable as they are isolated and decoupled from the more complicated aspects of messaging.

This combination allows for a configuration inside of Startup.cs that pairs instances of the listener service for the currently running messaging platform with any number of handlers. It also allows for quick development of new handlers as they are focused only on the task of handling a specific event.

RabbitMQ implementation

The RabbitMQ implementation adds a step that refactors the way events are handled when running locally or self-hosted. Instead of writing directly to the Events table via the EventsRepository, each event is broadcast to a RabbitMQ exchange. A new RabbitMqEventListenerService instance, configured with an EventRepositoryHandler, subscribes to the RabbitMQ exchange and writes to the Events table via the EventsRepository. The end result is the same (events are stored in the database), but the addition of the RabbitMQ exchange allows for other integrations to subscribe.

To illustrate the ability to fan-out events, a RabbitMqEventListenerService instance, configured with a WebhookEventHandler subscribes to the RabbitMQ events exchange and POSTs each event to a configurable URL. This is meant to be a simple, concrete example of how multiple integrations are enabled by moving to distributed events.

Running the RabbitMQ container

1. Verify that you've set a username and password in the .env file (see .env.example for an example)

2. Use Docker Compose to run the container with your current settings:

   docker compose --profile rabbitmq up -d
   • The compose configuration uses the username and password from the env file.
   • It is configured to run on localhost with RabbitMQ's standard ports, but this can be customized in the Docker configuration.

3. To verify this is running, open http://localhost:15672 in a browser and login with the username and password in your .env file.

Configuring the server to use RabbitMQ for events

1. Add the following to your secrets.json file, changing the defaults to match your .env file:

   "eventLogging": {
     "rabbitMq": {
       "hostName": "localhost",
       "username": "bitwarden",
       "password": "SET_A_PASSWORD_HERE_123",
       "exchangeName": "events-exchange",
       "eventRepositoryQueueName": "events-write-queue",
       "webhookQueueName": "events-webhook-queue",
     }
     "webhookUrl": "<HTTP POST URL>",
   }

2. (optional) The webhookQueueName and webhookUrl specified above are optional. If they are defined, a WebhookEventHandler will be added to a RabbitMqEventListenerService instance that will POST the event to the configured URL.

   info

   RequestBin provides an easy to set up server that will receive these requests and let you inspect them.

3. Re-run the PowerShell script to add these secrets to each Bitwarden project:

   pwsh setup_secrets.ps1

4. Start (or restart) all of your projects to pick up the new settings

With these changes in place, you should see the database events written as before, but you'll also see in the RabbitMQ management interface that the messages are flowing through the configured exchange/queues.

Azure Service Bus implementation

The Azure Service Bus implementation is a configurable replacement for Azure Queue. Instead of writing Events to the queue to be picked up, they are sent to the configured service bus topic. An instance of AzureServiceBusEventListenerService is then configured with the AzureTableStorageEventHandler to subscribe to that topic and write Events to Azure Table Storage. Similar to RabbitMQ above, the end result is the same (events are stored in Azure Table Storage), but the addition of the service bus topic allows for other integrations to subscribe.

As with the RabbitMQ implementation above, a WebhookEventHandler can be configured to run and POST events to a URL via a separate subscription.

Running the Azure Service Bus emulator

1. Make sure you have Azurite set up locally (as per the normal instructions for writing events to Azure Table Storage). In addition, this assumes you're using the mssql default profile and have the ${MSSQL_PASSWORD} set via .env.

2. Run Docker Compose to add/start the local emulator:

docker compose --profile servicebus up -d

info

The service bus emulator waits 15 seconds before starting. You can check the console in Docker desktop or run docker logs service-bus to verify the service is up before launching the server.

Configuring the server to use Azure Service Bus for events

1. Add the following to your secrets.json in dev to configure the service bus:

	"eventLogging": {
	  "azureServiceBus": {
		"connectionString": "\"Endpoint=sb://localhost;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=SAS_KEY_VALUE;UseDevelopmentEmulator=true;\"",
		"topicName": "event-logging",
		"eventRepositorySubscriptionName": "events-write-subscription",
	  }
	},

2. Re-run the secrets script to publish the new secrets

pwsh setup_secrets.ps1 -clear

3. Start or re-start all services, including EventsProcessor.

Configuring the webhook (optional)

1. Edit the servicebusemulator_config.json file to add a subscription to the main event-logging topic:

{
  "Name": "events-webhook-subscription"
}

2. Restart the server-bus container to pick up these changes

3. Add the webhook subscription name and URL configuration to secrets.json

  "eventLogging": {
    "azureServiceBus": {
    "connectionString": "\"Endpoint=sb://localhost;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=SAS_KEY_VALUE;UseDevelopmentEmulator=true;\"",
    "topicName": "event-logging",
    "eventRepositorySubscriptionName": "events-write-subscription",
    "webhookSubscriptionName": "events-webhook-subscription"
    },
    "webhookUrl": "<Optional URL here>"
  },

4. Publish the new secrets to the apps:

   pwsh setup_secrets.ps1 -clear

5. Restart all services, including EventsProcessor