title: Securing Microservices that use Spring Cloud & Netflix's Eureka and Feign
body: <p>I'm trying to figure out the best way to structure and implement microservices using Spring Cloud and Netflix's stack, specifically using Eureka and Feign. I have a few security related questions regarding each:</p>
  
  <ol>
  <li><p>I've seen that you can configure Eureka Server with a username / password credential. This keeps out unauthorized apps, but then each app must share credentials to access Eureka. Is there a simple way to create a registry of credentials so each microservice can have it's own? (It would be sweet to hook it into Spring Security's stack -- <code>UserDetailService</code> and the like) </p></li>
  <li><p>Once the microservices are wired up and communicating over feign, is it possible to share / pass the credentials used on an original request to additional calls that are made to other microservices? So if "Jim" requests <code>/foos</code> on <strong>FooService</strong>, and <strong>FooService</strong> requests <code>/bars</code> on <strong>BarService</strong>, <strong>BarService</strong> would know that it was Jim requesting them? </p></li>
  </ol>
  
  <p>Jim > FooService > BarService - where BarService knows the request is being handled for Jim...  </p>