Practical Microservices

Adding Email to the Registration Process

Next, we’ll teach the identity Component to send a welcome email when users register. Backhere you wrote Registered events in the identity Component. We’ll use those events as the trigger to send a registration email. Yes, when we’re done, identity will respond to its own messages. There is absolutely nothing wrong with that.

We also need to introduce a new event owned by the identity Component. Since we’re going to send emails in response to messages, we’ll need a way to project an identity and know if the email has already been sent. To that end, we introduce the RegistrationEmailSent event:

{
  "id": "2ea97206-10a4-46ac-aa4a-ba48e0cdd450",
  "type": "RegistrationEmailSent",
  "data": { ...