title: Is it possible to have partially federated gateway?
body: <p>I'd like to federate services, but let the federation gateway also hold own schema and logic that would proxy REST API endpoints for simplicity. Now it looks like I need to have federation gateway service, federated graphql service(s) and the rest&lt;->graphql bridge service separately. Anyhow in our case the rest-graphql gateway could be living in the federation-gateway at least for the time being to avoid unnecessary bootstrapping &amp; maintenance. </p>
  
  <p>Looks like Apollo federation gateway has <code>localServiceList</code> that seemingly serves exactly this purpose. An example config:</p>
  
  <pre><code>const gateway = new ApolloGateway({
      serviceList: [
          { name: "some-service", url: "http://localhost:40001/graph" }
      ],
      localServiceList: [
          { name: "rest-bridge", typeDefs }
      ]
  });
  </code></pre>
  
  <p>But it does not do the trick: If there is localServiceList, it skips the serviceList.</p>
  
  <p><strong>So the question is</strong>: Is this possible to hold also own schema &amp; logic in Apollo Federation gateway?</p>