title: How to access authenticated user out of controller context
body: <p>I have a question regarding access to the logged in user, when following the Nest.js guide on authentication (<a href="https://docs.nestjs.com/techniques/authentication" rel="nofollow noreferrer">https://docs.nestjs.com/techniques/authentication</a>). I'm using mongoose as my database driver, and all my data is persisted to MongoDB (user data as well). I want to have "createdBy" and "updatedBy" fields on each document saved or updated in the database. </p>
  
  <p>This can be done by adding these during the schema.pre('save', function() {}) callback, when defining the schema. But I have no way to access the current user performing the save action. The current logged in user is saved in request after the request passes the jwt auth guard. </p>
  
  <p>How do I get a hold of this user at the point of the schema.pre('save') callback?</p>